Pitfalls in seismic interpretation

FINAL REPORT

2009 INDUS BASIN 3D MARINE SEISMIC SURVEY

FOR BP PAKISTAN

USING M/V GEOWAVE CHAMPION

25th February 17th April 2009

Report No. : EOM1171 RPS Energy, Nelson House,Author(s) : John Granville & Coombe Lane, Axminster, Eryl Jones Devon. EX13 5AX, UK. T +44 (0)1297 34656 F +44 (0)1297 33277Date : 10th July 2009 E [email protected] W www.rpsgroup.com

BP Pakistan/EOM1171/JG/EJ/dm/df

CONTENTS Title Contents Page Number

1. INTRODUCTION 1 1.1. SUMMARY OF EVENTS 1

2. SURVEY SUMMARIES 4 2.1. POSITIONING PARAMETERS 4 2.2. RECORDING PARAMETERS 5 2.3. STREAMERS 5 2.4. SOURCE 6

3. PROJECT SUMMARY 7 3.1. DESIGN 7 3.2. SEISMIC INTERFERENCE 7 3.3. TIDAL AND OCEAN CURRENTS, STREAMER FEATHER ANGLES 8 3.4. WEATHER AND SEA CONDITIONS 8 3.5. CREW CHANGES 8 3.6. SHIPPING ACTIVITY 9 3.7. FISHING ACTIVITY 9

4. ENERGY SOURCE 10 4.1. SEAMAP GUNLINK 2000 CONTROLLER SPECIFICATIONS 10 4.2. COMPRESSOR PLANT 10 4.3. SYSTEM PERFORMANCE 10

5. STREAMERS 11 5.1. SYSTEM DESCRIPTION 11 5.2. DEPTH CONTROL AND HEADING SENSORS 11 5.3. AUTOMATIC STREAMER RETRIEVER SYSTEM 11 5.4. EQUIPMENT PERFORMANCE 11

6. RECORDING SYSTEM 13 6.1. RECORDING PARAMETERS 13 6.2. SYSTEM OVERVIEW 13 6.3. SYSTEM PERFORMANCE 13

7. NAVIGATION AND POSITIONING 14 7.1. GEODETIC PARAMETERS 14 7.2. CALIBRATION AND VERIFICATION OF NAVIGATION SYSTEMS 14 7.3. VESSEL POSITIONING 16

7.3.1. GPS Positioning 16 7.3.2. Heading Sensors 18 7.3.3. Echo Sounder, Velocity Profiles and Tidal Corrections 19 7.3.4. Current Meter 21

7.4. SOURCE AND STREAMER POSITIONING 21 7.4.1. Relative GPS 21 7.4.2. Acoustics 22 7.4.3. Streamer Compasses 24


7.5. INTEGRATED NAVIGATION AND PROCESSING SYSTEM 25 7.6. 3D BINNING 25 7.7. POSITIONING DATA QUALITY 26

8. DATA PROCESSING AND QC 32 8.1. HARDWARE 32 8.2. SOFTWARE 32 8.3. QC PROCESSING FLOW 32

8.3.1. Reformat Processing Flow 32 8.3.2. Basic Stack 3D Processing Flow 32 8.3.3. Basic Offset QC Processing Flow Chart 32 8.3.4. Basic Means Processing Flow 33

8.4. QUALITY CONTROL OUTPUT 33 8.5. REQUIRED DELIVERABLES 33 8.6. PERFORMANCE COMMENTS 33

9. PERSONNEL LIST 35

10. HEALTH, SAFETY AND ENVIRONMENT 37 10.1. HEALTH 37 10.2. SAFETY 37 10.3. ENVIRONMENTAL ISSUES 37

11. VESSELS 39 11.1. GEOWAVE CHAMPION 39 11.2. SUPPORT AND STREAMER GUARD VESSEL VENTURE G 39 11.3. SUPPLEMENTARY CABLE GUARD VESSEL AL MASHALA 40

12. CONCLUSIONS AND RECOMMENDATIONS 41 12.1. DATA ACQUISITION 41 12.2. COVERAGE 41 12.3. HSE 41 12.4. CONTRACT 42 12.5. EQUIPMENT TOWING CONFIGURATION 42 12.6. STREAMERS 42 12.7. ENERGY SOURCE 42 12.8. SERCEL SEAL RECORDING INSTRUMENTATION 42 12.9. NAVIGATION AND POSITIONING SYSTEMS 43 12.10. GEOWAVE CHAMPION 43 12.11. PERSONNEL 43 12.12. MARINE MAMMAL OBSERVERS 44 12.13. PAKISTAN NAVAL OFFICER OPERATIONS OBSERVER 44

13. PROJECT TIMING ANALYSIS AND COMMENT 45 13.1. ANALYSIS TABLE BY ACTIVITY 45 13.2. ANALYSIS TABLE BY CATEGORY 45 13.3. COMMENTS 45



APPENDICES APPENDIX A Location Map and Prime Lines

Coverage Plots Examples of Inline and Crossline Stacks Timeslices Vessel Positioning and In-water Equipment Layout Diagrams Vessel Specifications Operations Log Line Information Summaries Project Production Tables and Charts Timing Analysis Tables and Charts Navigation QC Charts and Plots

APPENDIX B APPENDIX C APPENDIX D APPENDIX E APPENDIX F APPENDIX G APPENDIX H APPENDIX I APPENDIX J APPENDIX K FIGURES FIGURE 1 Contour Map Image generated from all E Records extracted

from P1/90 files FIGURE 2 Acoustic Networks FIGURE 3 Front Acoustic Network FIGURE 4 Source Separations (Crossline) FIGURE 5 String to String Separations (Inline) FIGURE 6 Streamer Head Separations (Crossline) FIGURE 7 Overall Streamer Separations FIGURE 8 Inline Average CofS to CNG FIGURE 9 Average Values for Streamer Rotations FIGURE 10 Average Values for Streamer Misclosures (Inline Misc) TABLES TABLE 1 Gyrocompass Calibration Results TABLE 2 DGPS Verification Results TABLE 3 RGPS Range and Bearing Observations of 4 Receivers TABLE 4 Veripos DGPS Reference Stations TABLE 5 Fugro MRDGPS Reference Stations TABLE 6 SAIV T/S Dip Results TABLE 7 Sippican T/S Dip Results TABLE 8 Binning Parameters for Offset Groups TABLE 9 Tapered Bin Expansion TABLE 10 Average Node Network Error Ellipses Semi-major axes TABLE 11 NRT A Priori Observation SDs TABLE 12 Average Source and Source Array Separations TABLE 13 Average Streamer Separations TABLE 14 Analysis by Activity TABLE 15 Analysis by Category

1. INTRODUCTION BP Pakistan contracted RPS Energy to provide on board geophysical and positioning supervision for the duration of the 2009 Indus Basin 3D deepwater marine seismic programme. Please find the project location and programme maps in APPENDIX A. RPS Energy proposed and BP accepted John Granville to carry out geophysical supervision and for Eryl Jones (also RPS Energy) for positioning. Patrick Haines (GeoGuide) was assigned an HSE supervisory role aboard the chosen vessel throughout the entire project. With the duration of the survey expected to be approximately 40-50 days it was agreed that the team of 3 would most likely remain on the vessel throughout, and that proved to be the case. The contractor for the survey was Wavefield Inseis utilising their survey vessel the Geowave Champion. Please find vessel details in APPENDIX F. The acquisition parameters were an industry standard 10 x 6000 m spread of streamers (100 m between each) and a flip-flopping source array of 3460 in. Please find source and streamer configuration diagrams in APPENDIX E. Initially the project area covered 2,014 km (full-fold) with a total of 66 lines oriented on a 312/132 heading, 33 lines with a sail length of 79.525 km (76.525 km full-fold) and 33 lines 45.550 km (42.550 km full-fold) in length. On 13th March 2009 the 33 shorter lines were lengthened to 79.525 km, creating a final full-fold programme of 2,525.325 km. Two programme maps in APPENDIX A display the original programme and also when the lines were extended. The Champion completed her previous project (for Eni Pakistan) on 20th February 2009 and there then followed several days of streamer work (21st-24th) before she was ready to commence acquisition for BP. It had been agreed that should the vessel be ready and the BP Representatives had yet to arrive on board then acquisition should start. This proved to be the case although only one line had been recorded when John Granville arrived at 16:00 (local) on the afternoon of 25th February 2009. Once the data for the first sequence had been reviewed and accepted the mobilisation document was signed off. Due to difficulties with the numbers of personnel travelling (the mobilisation coincided with the scheduled crew change on 25th and 26th February 2009), Eryl Jones and Patrick Haines were obliged to wait until the morning of 26th to fly out to the vessel. The focal point with respect to technical issues and general operations was Mike Smith (BP Sunbury-On-Thames), whilst the primary recipient of the daily report was Younus Sheikh, BP Pakistans Offshore Operations Manager based in Islamabad. 1.1. SUMMARY OF EVENTS

Date 2009 Event 23rd February John Granville travelled from home to Dubai, Eryl Jones was delayed due to

problems with a flight connection. 24th February John Granville arrived in Karachi, Eryl Jones en route.

Pre-survey brief at the Ramada Hotel, BP and Wavefield staff in attendance. 25th February Geowave Champion commenced production at 00:55 GMT.

Crew change helicopter flights commenced, John Granville aboard at 11:00. 26th February Prime line acquisition.

Eryl Jones and Patrick Haines arrived aboard Geowave Champion on first and second flights.

27th February Prime line acquisition. 28th February Prime line acquisition.

BP Pakistan/EOM1171/JG/EJ/dm/df 1


Date 2009 Event 1st March Prime line acquisition.

Support vessel Venture G departed for Karachi for fuel and stores. 2nd March Prime line acquisition. 3rd March Prime line acquisition. Venture G back on station. 4th March Prime line acquisition. 5th March Prime line acquisition. 6th March Prime line acquisition. 7th March Prime line acquisition and a single catch-up infill. 8th March Prime line acquisition, Sequence 021 aborted due to source problem. 9th March Prime line acquisition.

Large fishing net snagged on the S7-S8 separation rope, acquisition suspended in order to remove it.

10th March Production resumed at 01:38 on a short section of infill. Prime line acquisition thereafter. Venture G alongside Champion from 08:00-17:20 local time, transferring 850 m3 of fuel.

11th March Prime line acquisition. Source separation rope from string 1 to S3 snapped, acquisition suspended from 00:17 to 02:14.

12th March Prime line acquisition. 13th March Prime line acquisition. 14th March Prime line acquisition. 15th March Prime line acquisition. 16th March Prime line acquisition. 17th March Prime line acquisition.

Large fishing net snagged on S3-S4 separation rope, line continued to end point.

18th March Prime line acquisition. Production suspended at 05:26 to recover guns and remove fishing net.

19th March Production resumed at 04:28 with completion of reshoot (Sequence 021 on 8th March) followed by infill.

20th March Infill acquisition. 21st March Infill acquisition to completion of first half of the block, prime line acquisition

on the second half commenced at 12:38. 22nd March Prime line acquisition. 23rd March Prime line acquisition. 24th March Prime line acquisition. 25th March Prime line acquisition. 26th March Prime line acquisition. 27th March Prime line acquisition. 28th March Prime line acquisition. 29th March Prime line acquisition. 30th March Prime line acquisition.

Production suspended at 08:37 to recover guns and remove fishing net. Production resumed at 23:17 on a short section of infill.

31st March Partial infill and prime acquisition 1 helicopter flight for crew change. 1st April Prime and infill acquisition 3 helicopter flights for crew change. 2nd April Prime and infill acquisition 2 helicopter flights for crew change. 3rd April Prime line acquisition. 4th April Prime line acquisition 1 helicopter flight for crew change. 5th April Prime line acquisition. 6th April Prime line acquisition. 7th April Prime line acquisition.


Date 2009 Event 8th April Prime line acquisition. 9th April Prime and infill acquisition. 10th April Prime and infill acquisition. 11th April Prime and infill acquisition. 12th April Infill acquisition. 13th April Infill acquisition. 14th April Infill acquisition finished, project satisfactorily complete.

Commenced recovery of all in-water equipment. 15th April Recovering streamers. 16th April Recovering streamers John Granville, Eryl Jones and Patrick Haines to

Karachi by helicopter. 17th April Recovery of all in-water equipment complete, Geowave Champion transited

to Karachi and dropped anchor whilst awaiting clearance. John Granville, Eryl Jones and Patrick Haines en route to London via Doha.

2. SURVEY SUMMARIES 2.1. POSITIONING PARAMETERS Working Datum : WGS84 Spheroid Parameters Spheroid : WGS84 Semi-major axis : 6378137.000 m Inverse Flattening : 298.25722356 Projection Parameters Type : Transverse Mercator TM66NE Latitude of Origin : 00 00 00.000 N Longitude of Origin : 066 00 00.000 E False Easting : 500000.000 m False Northing : 0.000 m Scale Factor : 0.9996 Grid Unit : 1 m Vertical Datum : Mean Sea Level Geoid Height Value : -48.82 m Location (Survey Centre) : 22 42N, 66 46E Origin of Value : EGM-96 Magnetic Declination Value : 0-164 changing by 0.042/year (24th Feb 2009) Location : 22 42N, 66 46E Origin of Value : IGRF-10 Vessel Positioning Systems System 1 : Fugro SkyFix-XP SDGPS System 2 : Veripos Ultra SDGPS System 3 : Veripos Standard Plus DGPS System 4 : Fugro MRDGPS Source Arrays : Konsberg Seatex 320 Tailbuoys : Konsberg Seatex 220 Streamer Compass Positioning and Depth Control Compasses : ION DigiCOURSE 5011 Number per Streamer : 23 Separation : 300 m or less Acoustics : Sonardyne SIPS 2 Binning Parameters X Origin : 561696.27 Y Origin : 2554775.27 Azimuth J : 132.0 Bin Size DX Inline : 6.25 m Bin Size DY Crossline : 25.00 m


Coverage Parameters Nominal Fold : 60 Offset Field Length : 1500 m Number of Fields : 4 Expanded Binning : Tapered: 37.5 m near to 75 m far Minimum coverage for Nears : 90% Minimum coverage for Near Mids : 80% Minimum coverage for Fars Mids : 65% Minimum coverage for Fars Mids : 50% 2.2. RECORDING PARAMETERS Recording System : Sercel Seal Version 5.2.10 Number of Data Channels : 4800 plus auxiliaries Streamer 1 Starboard Outer : Channels 3 482 Streamer 2 : Channels 483 962 Streamer 3 : Channels 963 1442 Streamer 4 : Channels 1443 1922 Streamer 5 : Channels 1923 2402 Streamer 6 : Channels 2403 2882 Streamer 7 : Channels 2883 3362 Streamer 8 : Channels 3363 3842 Streamer 9 : Channels 3843 4322 Streamer 10 Port Outer : Channels 4323 4802 Sample Rate : 2 ms Record Length : 8050 ms Nominal Fold : 60 Recording Start Delay : -50 ms Recording Polarity : SEG convention - Positive pressure is recorded as a

negative number on tape Recording Media : Dual recording to 3592 IBM 20 GB cartridge Media Format : SEG-D 8058 rev.132 bits IEEE Low-cut Filter : 3 Hz at 6 dB/oct Hi-cut Filter : 200 Hz at 370 dB/oct Shot Interval : 25 m

2.3. STREAMERS Streamer Type : Digital Manufacturer : Sercel Seal Oil filled Number and Active Length : 10 x 6000 m Separation : 100 m Group Interval : 12.5 m Group Length : 12.5 m Streamer Depth : 8.0 m 1 m Hydrophones per Group : 16 Hydrophone Sensitivity : 17.4 V/bar Hydrophone Spacing : Evenly along section length Compass/Depth Controllers : 23 per streamer Acoustic Units : Streamers 1, 2 and 3 2 front - 2 centre - 3 tail : Streamers 4, 5, 6 and 7 3 front - 2 centre - 3 tail : Streamers 8, 9 and 10 2 front - 2 centre - 3 tail Tailbuoys : On each streamer rGPS and acoustics Configuration : Please see diagrams in APPENDIX E


2.4. SOURCE Number of Source Arrays : 2 Number of Sub-arrays : 3 Sub-array Layout : Please see array diagram in APPENDIX E Shot Interval : 25 m Array Volume : 3460 in3 Array Separation : 50 m Array Depth : 6 m Array Length : 15 m (centre of front pair to centre of rear pair) Array Width : 15 m Sub-array Separation : 10 m Gun Manufacturer and Model : Bolt LongLife 1500 LL and 1900 LLXT Number of Guns in Full Array : 30 (including spares) Operating Pressure : 2000 psi Source Controller : Seamap GunLink 2000 software Version 2.5.2 Near Field Hydrophones : On each cluster and on each single Depth Transducers : Front, centre and rear Source Acoustics : Pod at the rear of every array


3. PROJECT SUMMARY 3.1. DESIGN The Indus Basin 3D followed on from an extensive 2D programme that BP Pakistan conducted in 2007. The main target of the survey was to image the biogenic gas features in the Miocene, around 2 to 3 s below the water bottom. Imaging the short wavelength channels required frequencies up to around 70 Hz. To achieve this, the streamers were towed at 8 m, which gave good high frequency content but at the same time did not introduce noise from the long wavelength swell which is common in the Arabian Sea. As the AVO response of the target sands was important for this survey, the cable length was chosen to be 6000 m which would deliver the far offset data necessary for the AVO analysis. The 6000 m cables were also able to image the deep structure containing the source rock which was a secondary target. Due to the canyonised water bottom, depth conversion and depth migration is an important objective, and the 6000 m cables were necessary to help define the velocity model. Results from the "fast track" migrated cube indicate that the survey geophysical objectives were met. 3.2. SEISMIC INTERFERENCE No other seismic vessels were operating in the immediate vicinity of the project and no random interference was seen from other seismic survey operations, although radio traffic and the Champions automatic vessel identification system did pick up some ships operating far to the southeast (in Indian waters). Three lines (1231 Sequence 041, 1291 Sequence 033 and 1331 Sequence 029) were affected by what remains an unidentified source of interference that (due to its regularity) can only be man-made. The 3 lines were all shot on a heading of 132 and by assessing the shot ranges on each, the interference occurred within a 30 km area near the submarine trench known as The Swatch. When first seen it manifested itself as a slow rising burst of energy (over a period of approximately 2 minutes) up to around 40 bars that on the Seals rms streamer noise monitor affected a total of 4 shots, this was followed by silence for 6 shots, it then returned for another period of 4 shots (2 minutes). When on one occasion it was seen to be stronger on the port streamers, slowly weaken and then shortly afterwards become stronger on the starboard streamers, the only conclusion that could be reached was that it was sonar emissions from a submarine. However, after narrowing down the locations where it was seen and finding that all 3 were in close proximity to The Swatch it would now appear that some kind of distorted return of Champions own shot energy was seen, but why it was only seen on the 3 lines mentioned earlier, not on any 2 adjacent lines, and why for only 3 or 4 out of 10 shots fired cannot be adequately explained. The bathymetry map created from the Champions echo sounder data by navigation representative Eryl Jones (please see APPENDIX K) shows that The Swatch extends much further out across the northwest end of the project area than had initially been expected (based upon the Admiralty chart) and that its northwest and southeast edges are not at all straight, the trench meanders much like a slowly flowing river. Perhaps this explains the irregularity, line to line and shot range to shot range, of when the interference was seen. The only way to confirm that it was Champions own shot energy would be to reshoot one of those sections again and see if it could be re-created.


3.3. TIDAL AND OCEAN CURRENTS, STREAMER FEATHER ANGLES An extensive Internet search was made at the start of the project to try to locate ocean and tidal current data for the Arabian Sea and none that would assist in the project planning could be found. Given the lengths of the lines (79.525 km/average online time 10.3 hours) it would have been impossible to hold to a regular cycle using the data to optimise the coverage anyway. Shortly after the start of the project a sample of tidal data from BP in the UK was matched with the elevation data from the vessels position and showed a very close correlation, however whether the irregular and unpredictable lateral movements of the streamers along any given line on the project can be specifically attributed to tidal or ocean currents or a combination of the 2 would be speculative. The decision was made very early in the project to acquire 2 swaths and steer the vessel as efficiently as possible. Regardless of whether the currents were tidal or oceanic they were certainly strong and during the initial phase of the project (the northwest half of the block) swings of 24 during a line became normal. There was speculation that the submarine trench, The Swatch, was partly responsible and that may well be the case, but given the fact that large and rapid changes in the current direction were observed well away from it (which affected the ability of the Navigators to steer the vessel and the range of the feather angles) then it is clear that strong tidal and ocean currents move through the entire project area continuously. Given that at times during March the total online time on the 132 heading was less than 10 hours, whilst it was more than 11 hours (close to 12 on one occasion) on the 312 heading seems to prove that there are continuous ocean currents made stronger at certain times by tidal movements. 3.4. WEATHER AND SEA CONDITIONS No weather downtime was accrued throughout the duration of the programme. The wind direction varied on a day to day basis but rarely held above 20 knots for sustained periods and sea conditions were never reported as having exceeded 1.5 m. The atmospheric conditions were very stable during the month of March with very little cloud, during early April there appeared to be a brief change with light rains and much higher humidity. 3.5. CREW CHANGES Crew changes took place on a 5 week on 5 off schedule via helicopter from Karachi on 25th/26th February, 31st March, 1st and 2nd April 2009. Wavefield Inseis contracted the Abu Dhabi Helicopter Company for the duration of the project using a AW (Augusta-Westland) 139 aircraft throughout, with ex-patriot pilots. The range of the project from Karachis main airport meant that the aircraft was never able to fly with a full passenger and baggage load, the consequences being that several round trips were needed to complete a full crew change (e.g. 6 for the 31st March-1st April 2009 crew change). The aircraft was on stand-by in Karachi throughout the project providing medevac support if required.


3.6. SHIPPING ACTIVITY As one would expect in this area of the Arabian Sea, significant shipping activity was seen throughout the entire period of the project, mainly following a northwest-southeast track between the Arabian Gulf and India/Southeast Asia. The bridge officers were able to keep these vessels significantly far away such that the noise generated by their propellers was kept to a minimum, although it was rare to record a line without there being some noise on the records. 3.7. FISHING ACTIVITY Fishing was limited to small local boats and these remained outside the project area. However, there were 3 incidents during the project that forced a suspension of data acquisition because large fishing nets had become snagged on the front-end streamer separation ropes 7-8 (9th March 2009), 3-4 (18th March 2009) and the starboard paravane (30th March 2009). Fortunately the strength of the Kevlar ropes was sufficient to hold the enormous strain that was placed upon them until the nets were removed. If they had not it would have been likely that the nets would have snagged on one or more of the streamers instead resulting in their loss. On the third incident (30th March 2009 when a net snagged on the point where the starboard paravane tow rope connects to the Streamer 1-2 separation rope and Streamer 1 spur rope) the concern was that the tow ropes to the paravane could part resulting in the collapse of all the starboard streamers (1-5) in on themselves. The nets themselves were extraordinarily large (weighing several tons one would guess) and comprised the net itself, 30-40 small white pellet buoys, several large blue plastic barrels as end of net markers and large rocks acting as weights to hold the net vertical in the water. By the time they were pulled aboard the Champion they had become tight bundles that needed the hydraulic winches and cranes on the gun, streamer and top decks to drag them clear. All 3 appeared to be relatively new (there was very little marine growth) and would probably be seen as a considerable loss to their owners.


4. ENERGY SOURCE Number of Source Arrays : 2 Number of Sub-arrays : 3 Total Number of Guns : 30 (including spares) on each array Array Length : 15 m (centre of front pair to centre of rear pair) Array Width : 20 m Array Volume : 3,460 in Array Depth : 6 m Nominal Operating Pressure : 2000 psi Primary Amplitude : 55.02 bar m Peak to Peak Amplitude : 118.55 bar m Peak to Bubble Ratio : 24.86 Bubble Period (+) : 72.5 ms Bubble Period (-) : 125.25 ms Gun Manufacturer and Model : Bolt LongLife 1500 LL and 1900 LLXT Source Controller : Seamap GunLink 2000 Source Timing Specification : +/- 1.0 ms 4.1. SEAMAP GUNLINK 2000 CONTROLLER SPECIFICATIONS Manufacturer : Seamap Model : Seamap GunLink 2000 Controller Software Version : 2.5.2 Input gain : Programmable Parameter Back-up : Hard Disk Monitor : 17" AOC flat screen Synchronisation Model : Automatic individual Synchronisation : Typically +/- 1.00 ms Controller Timing Accuracy : +/- 0.1 ms Timing method : Positive threshold 4.2. COMPRESSOR PLANT Compressors : 3 Manufacturer : NEA Type : 57 Maximum Output Pressure : 1100 kW, 2000 cfm at 2,000 psi 4.3. SYSTEM PERFORMANCE All the systems performed well throughout the project and no major problems were encountered, one airleak and one separation rope parting accounted for just 9.9 hours of downtime, 0.84% of total project time. As production had already commenced when John Granville arrived on the Champion, the standard checks ahead of the first deployment on a project, solenoid click test, the physical measurement of each sub-array, the positions of the GPS units, acoustic pods, depth transducers and gun hydrophones and after deployment the pressure drop tests were carried out as each array was recovered for maintenance and re-deployed. String 1 8th March String 2 9th March String 3 10th March String 4 11th March String 5 12th March String 6 13th March * Precise diagrams for the individual arrays can be found in APPENDIX E.


5. STREAMERS 5.1. SYSTEM DESCRIPTION Streamer Type : Seal Digital - Kerosene filled polymer jacket Manufacturer : Sercel Number of Streamers : 10 Active Streamer Section Length : 150 m Section Diameter : 50 mm Group Interval : 12.5 m Group Length : 12.5 m Hydrophones per Group : 16 Hydrophone Sensitivity : 17.4 V/bar Streamer Depth : 8.0 m 1 m Cable Depth Control : 23 x DigiCOURSE 5011 controllers per streamer 5.2. DEPTH CONTROL AND HEADING SENSORS Manufacturer : DigiCOURSE Model : Digiscan Software Version : 5.01 In-water Unit Model : 5011 Depth control and heading sensor The DigiCOURSE 5011 compass bird has become almost an industry standard with respect to the provision of data on the depth and heading orientation of towed streamers. Whilst sending this information back to the vessels on board operators data is also provided on the following;

Reporting current depth and temperature Reporting battery usage in hours and minutes Reporting wing angle with a resolution of 0.1

5.3. AUTOMATIC STREAMER RETRIEVER SYSTEM Manufacturer : Concord Marine Systems Model : SRD-500S Number in Use : 21 - On every bird except first and last Release Depth : 48 m or 70 psi 5.4. EQUIPMENT PERFORMANCE Overall the streamers were well balanced and electrically sound, it should be noted that most of the equipment on the vessel is relatively new as the Champion was only mobilised in 2007. However, the crew had to work hard at keeping the compass birds and acoustics within specification by launching the workboat almost daily for several hours (when the sea conditions permitted them to do so) and replacing units that had failed due to a drop in battery power or that appeared to have some debris wrapped around them preventing the fins from moving. It should be noted that when the Indus Basin project commenced on 25th February 2009 the entire spread had been in the water for over 3 months, by the time it ended on 14th April 2009 it was 5 months. Two characteristics of the streamers stood out, one of which features prominently in the comments and statistics presented by Eryl Jones in Section 7.7 and APPENDIX K. This refers to the inconsistency of the separation distances of the inner streamers (predominantly 5 and 6), it could be satisfactorily explained away by vessel speed, the effect of the current flow (either


from ahead or from behind) or where the streamers were in relation to the prop wash from the Champion. The second feature was the vane turbulence that created noise on the outer streamers (1 and 10) when the streamers were in a bend as they moved laterally with the changing current. Neither could be satisfactorily explained away by the crew, nor were there any plans for the problem to be addressed at some stage in the future. Although the authors have not worked on every vessel in the seismic industry one would have to say that these 2 issues are not common to all vessels, the trousering effect on the shape of the streamers yes (although on the Champion that was not a problem) but not vane turbulence and consistent separation problems on the inner streamers.


6. RECORDING SYSTEM 6.1. RECORDING PARAMETERS Recording System : Sercel Seal Software Version : 5.2.10 Number of Data Channels : 10 x 480 = 4,800 Sample Interval : 2 ms Record Length : 8050 ms Recording Polarity : SEG convention - Positive pressure is recorded as a

negative number on tape. Low-cut Filter : 3 Hz at 6 dB/oct High-cut Filter : 200 Hz at 370 dB/oct Shotpoint Interval : 25 m Fold : 60 Tape Decks : 2 x IBM Tape Format : SEG-D Tape Medium : IBM 3592 cartridge 6.2. SYSTEM OVERVIEW As with all the recording systems industry wide the Sercels Seal acquires, processes and records data at variable sample rates. The system is flexible enough to be easily integrated with all the other component parts of a marine seismic vessels instrument room. Aboard the Geowave Champion it operated in conjunction with the vessels Spectra navigation software system and the Seamap GunLink 2000 gun controller. 6.3. SYSTEM PERFORMANCE No problems were encountered with the Seal and no downtime accrued throughout the project.


7. NAVIGATION AND POSITIONING 7.1. GEODETIC PARAMETERS Datum : WGS84 Ellipsoid : WGS84 Semi-major Axis : 6378137.000 m Inverse Flattening : 298.25722356 Projection : Transverse Mercator TM66NE Zone Number : N/A Latitude of Origin : 00 00 00.000 N Longitude of Origin : 066 00 00.000 E False Easting : 500000.000 m False Northing : 0.000 m Scale Factor at CM : 0.999600 Geoid-Ellipsoid Separation : -48.82 m (EGM-96) 22 42N, 66 46E Magnetic Declination : 0-164 changing by 0.042/year (24th February 2009) 22 42N, 66 46E IGRF-10 Vertical Datum : MSL Tidal Corrections : Supplied by BP Unit of Measurement : International metre

7.2. CALIBRATION AND VERIFICATION OF NAVIGATION SYSTEMS No pre-survey calibration or verification programme was carried out prior to the start of the operation. The vessel transferred directly from a previous project in the Arabian Sea without recovery of the streamers and without visiting a local port. Details of the most recent gyrocompass, DGPS and RGPS calibrations carried out alongside at Singapore on 25th October 2008 were supplied for examination. The checks were carried out by Swift Survey Pte Ltd for Wavefield Inseis Singapore Pte Ltd. The checks were considered to be minimal with the gyrocompasses checked on only one heading and only 4 rGPS receivers tested as a representative sample of at least 16 in use. Please find the report included in APPENDIX K. The details are briefly as follows: Gyrocompasses Three gyrocompasses were calibrated on a 45 heading only. Observations were made from shore based reference stations to points on the vessel centre-line at the bow and at the stern, and the true bearing derived between these 2 points. Gyro readings were logged simultaneously for comparison. The gyrocompasses were designated 1, 2 and 3 but there was no indication as to which instruments these actually were. Subsequent discussions with the Chief Navigator revealed that they were 1 - SG Brown Meridian Surveyor, 2 Simrad GC80 and 3 Robertson RGC11 respectively which was the same as the configuration for this operation. As the calibration was carried out on one heading only any differences could not be averaged and eccentricities in the instruments would not have been exposed. Low SDs did indicate that sufficient time had been allowed for the gyros to settle before the data was recorded. The results were as given in TABLE 1 below.


Gyro C-O SD 1 - SG Brown Meridian Surveyor -0.47 0.06 2 - Simrad GC80 +0.24 0.07 3 - Robertson RGC11 -0.06 0.16

TABLE 1 Gyrocompass Calibration Results It is apt to note that, apart from the facility of being able to compare the 3 gyro headings during the survey, there was no precise GPS based heading sensor such as Seapath to monitor the gyro headings, during the operation. DGPS Four DGPS systems were verified: SkyFix-XP, Veripos1, Veripos 2 and MRDGPS. The technique involved observing and computing the main primary antenna (SkyFix-XP) position from shore observations and comparing the position derived against observations of the positions of all 4 systems logged simultaneously on board. The positions of the other 3 systems were corrected relative to the XP antennae. The results are displayed in TABLE 2 below:

System Eastings Northings C-O (m) SD C-O (m) SD SkyFix-XP -0.68 0.20 +0.76 0.07 Veripos 1 -0.94 0.04 +0.41 0.04 Veripos 2 -0.69 0.70 -0.33 0.33 MRDGPS -0.91 0.46 -0.71 0.65

TABLE 2 DGPS Verification Results The reference stations used with MRDGPS were not representative of the selection used in the prospect area. No RINEX data was recorded whilst the vessel was alongside for online processing by Auspos (Geoscience Australia), Precise Point Positioning (Natural Resources Canada) or a similar service. RGPS Four Seatex tailbuoy rGPS receiver modules were set up on the quay and their positions derived by observations with survey equipment from known shore stations. Observations of the ranges and bearings to the buoys were recorded on board and compared to the computed distances and bearings known positions. The results are shown in TABLE 3 below:

Receiver Range Bearing C-O SD C-O SD Tb 4937 -0.31 m 0.64 0.00 0.04 Tb 2686 -0.18 m 0.67 -0.02 0.05 Tb 2227 +0.13 m 1.07 -0.03 0.03 Tb 2269 +0.72 m 1.12 -0.06 0.04

TABLE 3 RGPS Range and Bearing Observations of 4 Receivers The 4 rGPS receivers were only a representative sample of at least 16 used for the operation and the check was thus considered inadequate. However, all 22 of the receivers on board were tested en route from Singapore to the Arabian Sea between 30th October and 1st November 2008, and the results were provided for examination. Please find these results in APPENDIX K.


Echo Sounder An echo sounder check was carried out by the crew while the vessel was alongside at Singapore. The average depth from corrected measurements using a sounding line on both sides of the vessel was compared to the echo sounder readings. Observations were logged for three frequencies (12 kHz, 38 kHz & 200 kHz) and the C-O values were -0.70 m, -0.50 m and -0.27 m respectively. The results were acceptable and are included in APPENDIX K. T/S Dip Probe A calibration certificate dated 29th January 2007 was supplied by the contractor and a copy is included in APPENDIX K. 7.3. VESSEL POSITIONING GPS was used for navigation and absolute horizontal positioning of the vessels navigation reference point (NRP). The positions of sources and receivers were referenced to the vessel NRP for each shotpoint. Four GPS systems were employed to derive the vessel system position: Fugros SkyFix-XP, Veripos Ultra, Veripos Standard Plus and Fugros MRDGPS which are described below. All 4 systems were interfaced with the Concept Systems ORCA Integrated Navigation System (INS) which maintained shot control and steering. SkyFix-XP and Veripos Ultra were totally independent systems, provided by different contractors and were designated primary and secondary systems respectively. 7.3.1. GPS Positioning Fugro SkyFix-XP SDGPS SkyFix-XP is a decimetre level global dual frequency service provided by Fugro, utilising a technique referred to as Satellite Differential GPS (SDGPS) capable of overcoming the distance limitations of conventional differential GPS. The system provides global corrections for orbit and clock errors for each satellite and is supplied by NASAs Jet Propulsion Laboratory (JPL). Corrections were transmitted to the vessel via the Inmarsat B IOR satellite and on the L-Band frequency via the EA-Sat/AF-Sat High Power satellite beam. Corrections were received on the vessel via the Inmarsat tracking dome antenna (low power) and the smaller omni-directional SPOT antennae (high power) respectively. The corrections were routed through demodulators before being applied to the data for the GPS satellites being tracked at the vessel location. Comparisons of the GPS L1 and L2 frequencies at the vessel location were expected to eliminate potential ionospheric and tropospheric errors. GPS data was acquired via a dual-frequency receiver. SkyFix-XP operated in 3D Auto mode. The satellite elevation mask was maintained at 8. Correction update rate was in the region of 10 to 20 s. SkyFix-XP positions were processed through the MultiFix 5 software which also displayed performance, statistical and QC data although this information was not available post-line. Statistical testing for gross errors was carried out (W-test and F-test) in accordance with UKOAA recommendations to detect and reject correction outliners prior to being fed to ORCA. Carrier-phase smoothing reduced the random noise effects on the pseudo-ranges and assisted in multi-path detection. Statistics transferred in the output string to ORCA included the position, PDOP, HDOP, Number of Satellites, Error Ellipse SMA, Antenna Ellipsoid Height and Unit Variance.


Veripos Ultra PPP Veripos Ultra is a dual-frequency GPS system provided by Veripos, described as a Precise Point Positioning service and employing in many ways similar techniques to the SkyFix-XP system. The system claims to provide decimetre level accuracy and provides one set of corrections for all the satellites which are valid globally. Proprietary algorithms reduce satellite orbit, clock errors, multipath and noise while tropospheric and ionospheric errors were minimised with the aid of the dual-frequencies. Corrections were broadcast for each satellite via the Inmarsat 109E L-band communication satellite high-power level service and were received on the vessel through small omni-directional antennae. The correction update rate was in the region of 30 s. The satellite elevation mask was 10. The Veripos Ultra position was computed through the Veripos Verify QC software using data from the Veripos LD2 integrated mobile unit. Veripos QC provided real-time positioning and quality control information and transferred the data to ORCA. The LD2 mobile unit included a demodulator for the global satellite corrections and a dual-frequency GPS receiver. Veripos Standard Plus DGPS Veripos Standard Plus is a dual-frequency differential GPS system provided by Veripos. The multi-reference station solution was computed through the same Veripos Verify QC software as for Veripos Ultra and used data from the LD2 receiver/demodulator as described above. The dual frequencies were used to mitigate the effects of any potential ionospheric errors. Data from the Verify QC software was transferred to ORCA. The system operated in 3D mode with a satellite elevation mask of 10. Differential correction data was received from 5 reference stations distributed around the area of operations. Details of these stations are shown in TABLE 4 below: Station ID Latitude Longitude Distance *

Doha 904 25 16 49.52126 N 051 31 44.59088 E 1575 km Dubai 905 24 58 44.57070 N 055 02 36.76536 E 1220 km Mumbai 906 18 59 48.08518 N 072 49 09.18832 E 750 km Kolkata 907 22 34 07.66092 N 088 21 01.75261 E 2215 km Chennai 908 13 03 37.19581 N 080 14 54.38184 E 1780 km

TABLE 4 Veripos DGPS Reference Stations * Approx distance from centre of prospect (22 42 00.00 N, 066 46 00.00 E)

The differential correction data was received on the vessel in the same manner as for Verify Ultra via the High Power level service. Fugro Starfix.MRDGPS Starfix.MRDGPS is a single-frequency DGPS positioning system from Fugro which provides a multi-reference station positioning solution. MRDGPS is a Starfix Navigation Suite (V 8.1) software module. Pseudo-ranges are weighted according to user range accuracy, distance from the reference station, age of correction data, satellite elevation and receiver noise. With only one GPS frequency tropospheric and ionospheric corrections are computed from a model. The software complies with UKOOA requirements for statistical testing and data rejection. Statistical displays were available in real-time only. Data was transferred to ORCA for post-line statistics. MRDGPS ran in 3D mode with a satellite elevation mask of 6. The TABLE 5 includes a list of the reference stations used for the operation:


Station ID Latitude Longitude Distance *

Chennai 131 13 04 06.648 N 080 16 43.733 E 1785 km

Mumbai 191 19 03 38.599 N 073 00 55.099 E 765 km

Abu Dhabi 240 24 22 59.019 N 054 31 11.051 E 1265 km

Bahrain 263 26 13 04.497 N 050 34 31.507 E 1685 km

TABLE 5 Fugro MRDGPS Reference Stations * Approx distance from centre of prospect (22 42 00.00 N, 066 46 00.00 E)

Differential correction data was available on Low Power via the Inmarsat IOR communications satellite or on High Power via IORH, AF-Sat or AP-Sat.

GPS Systems Performance The performance and reliability of all 4 GPS positioning systems was excellent throughout the operation. There were no noted outages, or disturbances of any significance and no interruption to vessel positioning. There were occasional minor jumps in position but these were usually less than 1 m and were further diluted when combined with data from the other 3 systems to derive the vessel system position. Comparisons were provided between all 4 GPS system positions for each line through the ORCA end of line reports. The average radial difference between the 2 main systems, SkyFix-XP and Veripos Ultra was less than 1 m and well within the required standard. Data was continuously monitored by the system providers, Fugro and Veripos. Performance statistics were available from the providers if quality was questionable and required further investigation. Fortunately, there was no such occurrence that required further investigation. 7.3.2. Heading Sensors There were 3 gyrocompasses installed on the vessel. These included an SG Brown Meridian Surveyor located in the instrument room together with Robertson RGC11 and Simrad GC80 gyrocompasses located on the bridge. The SG Brown gyrocompass was designated the primary instrument. Data from all 3 instruments were logged to ORCA throughout the operation. Heading data was used primarily for vessel navigation and vessel offset computations (e.g. for GPS antennae, SIPS hull transceiver and echo sounder). Latitude and speed settings were manually set on all the instruments. All 3 gyrocompasses performed reliably throughout the operation with no noted problems and no evidence of drift relative to each other. The instruments were not calibrated immediately prior to the start of the operation. The most recent calibration took place at Singapore in October 2008 (please find the report included in APPENDIX K) and the details are discussed in Section 7.2 above. The correction values derived from this calibration were applied in ORCA. SG Brown Meridian: -0.47, Robertson RGC11: -0.06 and Simrad GC80: +0.24. Time series plots of raw uncorrected heading data and comparisons, were available for each line from the ORCA end of line reports. It is presently not uncommon to find a GPS based heading determination system such as, for example, Kongsbergs Seapath 200 on seismic vessels. Given the accuracy (0.05 RMS) of these GPS based headings, the data serves effectively as a real-time calibration system


acceptable for continuous gyrocompass calibration. There was no such system available on the Geowave Champion. Given that there was no calibration carried out at the start of the operation, and that the last calibration was considered to be less than adequate, it would have been advantageous to have had this facility available during the operation. Furthermore, there was no motion sensor/attitude determination system on board and as a result no pitch, roll and heave data were applied to the echo sounder. 7.3.3. Echo Sounder, Velocity Profiles and Tidal Corrections The Geowave Champion was equipped with a triple frequency Kongsberg Simrad EA 600 Series hydrographic single beam echo sounder operating on 3 transceiver frequencies (12 kHz, 38 kHz and 200 kHz). Only 2 frequencies (12 kHz and 38 kHz) were suitable for acquiring data over the depth ranges encountered in the prospect area which ranged from 545 m to 1698 m (recorded). The depth profile for both frequencies was available continuously for monitoring on a colour display and the digital data produced was recorded by ORCA which provided time series profiles at the end of each line. No real-time hard copy paper trace was available. Water depths were recorded with a fixed nominal velocity of 1500 m/s with the transducer set at a draught of 0.0 m in accordance with industry practice. Water depths in the P1/90 were corrected for vessel draught (5.8 m), tides and velocity of sound in water, the latter being based upon the full column value (1515 m/s) derived from the Sippican deployments at the start of the operation. As there was no motion sensor installed on the vessel, adjustments for pitch, roll and heave were not applied to the echo sounder data. Tidal correction data was supplied to the contractor by BP. The raw water depth data acquired for both useable frequencies was consistently good throughout despite the presence of some very steep slopes in the seabed topography. Problems were, however, experienced with the water depth data found in a large number of P1/90 files where it seemed that NRT, in the process of de-spiking and filtering the raw water depth data, had actually removed data from the final product. Firstly, it was unacceptable that NRT had removed good raw data during processing; and secondly the fact that the data was missing and had not been discovered by the navigation team, highlighted a lack of final data quality control on board. Where data was missing in the P1/90 files it was usually in groups of 10 to 15 shots. As a result the lines affected had to be reprocessed with Sprint to recover the data and the P1/90 files regenerated in ORCA from the database. This problem resulted in extensive communication between the contractor and Concept Systems with numerous transfers of data and installation of software patches. P1/90 files with missing water depths were still appearing sporadically right up until close to the end of the operation, indicating clearly that the problem had not been properly resolved. The echo sounder was last calibrated at Singapore in October 2008. Please find details included in Section 7.2 above and in APPENDIX K. Water depths generally increased to the southwest. Towards the northern end of the prospect a conspicuous submarine canyon referred to as The Swatch on the marine chart ran across the breadth of the prospect from the northeast to the southwest. The contour map image below has been generated from all the E records extracted from the P1/90 files.


FIGURE 1 Contour Map Image generated from all E Records

extracted from P1/90 files T/S Dips An SAIV STD/CTD SD204 velocity probe was used to acquire data for computing the velocity of sound in water at streamer depth (8 m) for validating the streamer velocimeter data. The probe was deployed from the workboat close to the area of operations on a more or less weekly basis when operationally practicable. The SAIV probe was autonomous and fitted with conductivity, temperature and pressure sensors plus a microprocessor to compute velocity values. Once the probe had been deployed and recovered, the data was downloaded directly into a computer and then brought back to the Geowave Champion. The probe was rated for use well beyond streamer depth but only about 300 m of rope was available therefore it could not be used for full water column measurements. Please find a summary of the results obtained in TABLE 6 below.


T/S Dips No Date Lat Long Velocity (at 7 m depth) 1 27th Feb 2009 225934 663459 1536.67 m/s 2 8th Mar 2009 224354 665028 1538.27 m/s 3 15th Mar 2009 223806 663459 1537.94 m/s 4 23rd Mar 2009 222854 670440 1539.21 m/s 5 29th Mar 2009 223700 664600 1539.77 m/s 6 5th April 2009 222736 665221 1540.87 m/s

TABLE 6 SAIV T/S Dip Results The velocity of sound in water as acquired from the SAIV probe for the 8 m streamer depth was entered into ORCA. This data was only used for the calculation of the Sonardyne SIPS ranges in ORCA if the real time velocimeter data was not available. Measurement of the full water column was made using Sippican XBT T-5 Expendable Bathythermograph (XBT) probes which measured temperature and computed sound velocity data. These probes were deployed from the chase boat Venture G on 3 occasions during the survey. TABLE 7 below lists the results of the Sippican deployments during the survey:

T/S Dips (Sippican) No Date Lat Long Velocity (Full Column) 1 28th Feb 2009 225800 664200 1522.64 m/s (-495.3 m) 2 12th March 2009 225000 663900 1514.53 m/s (-973.2 m) 3 12th April 2009 224825 665219 1509.52 m/s (-1722.6 m)

TABLE 7 Sippican T/S Dip Results 7.3.4. Current Meter A Nortek Acoustic Doppler Current Profiler (ADCP) was installed but was not operational. Reports indicated that a connecting cable on the hull was damaged. Current meters are always useful tools for predicting feather changes and for optimising infill. Extreme feather angles or sudden feather changes were generally, however, not a problem. The recording of the current patterns and magnitudes throughout the survey for future reference in the event of further exploration work would have been an advantage. 7.4. SOURCE AND STREAMER POSITIONING 7.4.1. Relative GPS RGPS receivers were deployed on buoys to provide reference positions for the source and streamer networks relative to the vessel NRP. The receivers, antennae and UHF telemetry modems were installed in modules on each of the 6 gunstring floats and each of the 10 tailbuoys as part of the Fugro Seatex Seatrack 220/320 rGPS tracking system. A 320 GPS receiver/transponder module was employed on each of the 6 gun arrays, with a 220 module on each of the 10 tailbuoys. All tracking modules featured single-frequency GPS receiver boards. GPS code and carrier phase data was transmitted to the vessel via low power UHF radio from the gunstring floats and tailbuoys. On board the vessel, the Seatrack VCU 200 transceiver module communicated with the remote units and directed the raw GPS data to the rGPS module of the Fugro Starfix Suite (V8.1) software. Slope ranges and bearings were then exported to ORCA for processing.


RGPS performance was very good overall and the receivers were resilient and reliable. RGPS headbuoys for reinforcing the front acoustic network were not deployed and, given the overall quality of the front network positioning there was no reason to consider using them. Acquisition was not compromised at any time through the failure of the rGPS positioning on either the gun arrays or the tailbuoys. The quality of the rGPS positioning was monitored for each line from the error-ellipse statistics for each of the networked rGPS source nodes. The average values were generally good but the maximum values were frequently unacceptable indicating that the NRT processing was not wholly adequate. Any lines with unacceptably high maximum error ellipse semi-major axis values were re-processed with Sprint. There were 2 problems experienced with the rGPS system during the course of the operation:

1. RGPS data on Tailbuoys 5, 6 and 7 dropped out for exactly 15 minutes from 00:15 to 00:30 just after midnight on Sunday mornings (UTC). This was attributed to software or firmware problems with those particular receivers but the situation was not resolved before the end of the operation. Sequences 008, 033 and 042 were affected. The outages did not prove to be detrimental to positioning of the tail network as the other 7 tailbuoys and the tail acoustics were operating during those periods.

2. Sporadic interference to the transmissions of data from the tailbuoys to the vessel was experienced. This did not prove to be a major problem. As VHF broadcasts from seismic vessels had been picked up over very long distances around the same time and because there were no potential sources anywhere in the area of operations, the interference was attributed to E-Skip from distant sources?

7.4.2. Acoustics The Sonardyne (Seismic Integrated Positioning System) SIPS 2 (V2.22.00.32) acoustic positioning system was employed in a 3 network arrangement. The 3 networks comprised streamer and tailbuoy mounted XSRS (Cross Streamer Ranging System) transceivers together with HGPS (Head and Gun Positioning System) transceivers on the vessel and gun-strings. Each XSRS had 1 transmit and 4 receive channels allowing simultaneous ranging between transceivers and the capability to receive 4 of 60 unique digital signals. Range data was transmitted to the vessel via the inductive coils contained within each streamer and data from the sources were transmitted via the umbilicals. The Controller on the vessel provided the interface between the transceivers and ORCA.

FIGURE 2 Acoustic Networks


The front acoustic network included a vessel hull HGPS transceiver, one HGPS shock mounted transceiver on each gunstring, and 3 XSRS transceivers mounted on each streamer, a total of 31 units. The front network was referenced to the surface positions provided by the rGPS receivers on each source array float.

FIGURE 3 Front Acoustic Network

The middle network included 2 XSRS acoustic transceivers on each cable a total of 20. The tail network used 3 XSRS transceivers on each streamer, including one on each tail stretch forward of the tailbuoy rGPS antennae a total of 30. The tail network was referenced to the surface positions of the rGPS receivers on the tailbuoys. The configuration and geometry of the networks presented for the project was adequate by current standards and also included a satisfactory level of redundancy. No changes were made to the original configuration after the start of the survey. Both one-way and 2-way ranges were used. The orientation of the individual networks was achieved with the streamer compasses. The reliability and performance of the acoustics system was very good overall. Situations where 100% of the transceivers were operational were common, particularly during the second half of the operation. There were no significant difficulties with reflections due to the water depths and conditions where the sea surface was calm and reflective were generally not a problem. Front end ranges were sufficiently robust to negate the need for headbuoys. Defective transceivers, or those with expired batteries, were usually replaced by workboat as soon as it was operationally practicable provided the sea conditions were suitable. Thirty-eight transceivers were replaced by workboat during the survey. Network adjustment statistics were provided at the end of each line as part of the NRT diagnostics. Three SIPS XSRS ASV combined transceivers/velocimeters were deployed, one in the front net on Streamer 4 (S4V1), one in the mid net on Streamer 8 (S8V1) and the third in the tail net on Streamer 9 (S9V1). Velocimeter data was generally good from all 3 sensors but there were 2 problems. Occasionally the Sonardyne DMU would not reset before the start of the line and as


a result the velocimeter data would be occasionally lost for a complete line. The velocimeter data would also occasionally become intermittent due to the growth of barnacles on the sensors which would have to be removed to rectify the problem. The velocimeter data was ordinarily used for computing the acoustic ranges in ORCA on a shot by shot basis. In the event that the velocimeter data was not available, the velocity as acquired from the weekly T/S Dip was used for the computations. Maintenance operations involved replacing units on the streamers for various reasons. These included replacement of batteries and defective units. Some of the transceivers had to be replaced because of corrosion to the stainless steel casings. The corrosion appears to have originated from a previous area of operations where the water was largely anaerobic. The transceivers thus affected were being gradually replaced by units with carbon fibre casings. 7.4.3. Streamer Compasses IONs DigiCOURSE Model 5011 DigiBirds were employed on the streamers to provide compass heading information for streamer shaping, streamer depth measurement and streamer depth control. Twenty three compass birds were deployed along each streamer distributed at intervals of 300 m or less. The second compass on each streamer was located between the first and second acoustic nodes. The birds were controlled via the DMU controller. Overall the performance of the streamer compasses was excellent; biases were low, failures were minimal, and they met the objective of providing continuous heading data. All compasses were filtered at source in the manufacturers software, as recommended, to avoid undue noise in the data. Given the overall good sea conditions the data was sampled at the minimum rate of 2 s intervals and averaged over 6 samples. The difference between the predicted compass value and the actual compass reading was tested at each shot. If the residual exceeded twice the standard deviation for 2 successive shots the online compass filtering was flagged as requiring post-processing. Normally, as expected, the first, and particularly the last compasses on each streamer were usually slightly noisier owing to the movement generated from the towing arrangements. Compasses with persistently high biases or correction values in excess of 1.0 were flagged for replacement and generally not used in processing. Distances between useable compasses were never greater than 300 m during the operation. There were no instances where 2 adjacent compasses in any part of the total network were deemed unusable. Please find details of the compass positions on the streamers in the drawings in APPENDIX K. No corrections derived from static calibrations were applied in ORCA. ION DigiCOURSE set the static corrections in new units and subsequently after servicing or repair. The manufacturer provided a 2 year warranty and advised that afterwards it is only necessary to monitor the compasses for persistent high biases from the dynamic calibrations or any errors following which they should be despatched for repair and recalibration. Calibration records were available by consulting the manufacturers website for a full list of the latest results for each individual compass unit. Faulty compasses were normally changed out as soon as was operationally practicable or as the weather permitted. Eighteen compasses were replaced by workboat during the operation. Compass statistics were provided at the end of each line as part of the ORCA and NRT diagnostics. The reports included biases, SDs and DSDs. Magnetic Declination The magnetic declination value for the prospect area acquired by the contractor from the IGRF10 (International Geomagnetic Reference Field 2010) model was 0.164 changing by


0.042 per year based on a position near the centre of the survey area 22 42 00 N, 066 46 00 E for 24th February 2009. This data was applied in ORCA. The value was verified using the Declination Calculator based on the IGRF10 World Magnetic Model: this facility was available at the US National Geophysical Data Centre (NGDC) website: http://www.ngdc.noaa.gov/geomagmodels/Declination.jsp No unusually erratic compass behaviour was observed during the operation. NOOA Solar Activity Forecasts consulted, indicated quiet geomagnetic field levels overall with no indications of abnormal solar geomagnetic disturbances. Archives were available at: http://www.swpc.noaa.gov/forecast.html

7.5. INTEGRATED NAVIGATION AND PROCESSING SYSTEM The Concept Systems ORCA (V 1.5.1) Integrated Navigation System (INS) provided real time navigation and positioning for vessel, sources and receivers together with final processing and on-line binning facilities. ORCA is a recent system which has evolved from the well established Spectra INS and includes the combined functionality of Spectra, Sprint and Reflex. Processing was carried out through the NRT (Near Real Time) module. As its title implies, NRT delivered the final processed positioning data soon after the end of a line following which ORCA generated the P1/90 and P2/94 files, binned the data, applied any necessary edits and generated the statistical QC reports. ORCA system time was referenced to GPS time acquired via a dedicated receiver. Overall, ORCA performed well and met the objectives. The contractors component identification convention numbered the streamers from starboard (1) to port (6). Gun arrays were similarly numbered from starboard to port. Streamer group numbers were numbered consecutively with, for example, Group 1 (near) to 480 (far) on Streamer 1, and Groups 481 (near) to 960 (far) on Streamer 2 and so on. The acoustic units and streamer compasses were numbered from front to tail, for example the first acoustic unit on the starboard outer streamer was S01T01 and the last S01T07, the first compass on Streamer 1 was S01C01, and the last S01C23. The Simrad-Robertson Robtrak autopilot on the vessel was interfaced with ORCA and was controlled online, and during line changes, by the Navigators who entered crossline offset deviations to steer for coverage or otherwise manoeuvre the vessel. At the end of each line comprehensive statistics were available, mostly numerical but with some time series charts. Statistics were provided for quality control purposes and in a suitable format for import into QC software. Passive LCD displays were available in the Client Office which allowed limited graphical monitoring of the progress of the current line together with some feather and separation data. Access to the ORCA Web Interface in the Client Office also allowed passive monitoring of events during the line in progress, together with information and reports for previous lines and the survey as a whole from the ORCA database. 7.6. 3D BINNING Binning was carried out by the ION Concept Systems Reflex system which fulfilled its function both online and offline for the duration of the survey. The streamers were divided into 4 equal offset groups as summarised in TABLE 8 with a minimum offset of 325 m:


http://www.ngdc.noaa.gov/seg/geomag/jsp/struts/calcDeclinationhttp://www.swpc.noaa.gov/forecast.html

Binning Parameters

Offset Range (m) 325-1825 1825-3325 3325-4825 4825-6325 Zone Nears Near-mids Far-mids Fars Minimum Coverage 90% 80% 65% 50% Used for Steering Yes Yes Yes Yes

TABLE 8 Binning Parameters for Offset Groups Bin Expansion Tapered bin expansion was used in assessing the coverage required ranging from 50% (nears) to 200% (fars).

Tapered Bin Expansion Zone Fold 60/60 Bin Size Start (m) Bin Size End (m) Threshold Nears 15 37.5 46.87 90% Near-mids 15 46.87 56.25 80% Far-mids 15 56.25 65.62 65% Fars 15 65.62 75 50%

TABLE 9 Tapered Bin Expansion Vessel Steering The vessel was steered through ORCA by the Navigator who assessed, using the data displayed as a guide, the required vessel offset needed to obtain the desired CMP coverage. The vessel was thus steered using a computer mouse with steering offsets entered in increments of 5 or 10 m. The steering was based on consideration of all offsets but with a main focus on near and near-mid offsets. Small holes of limited length and up to 2 columns in width were tolerated in the far offsets. Lines were acquired based on steering the coverage edge and with no overlap applied. Shooting Method The method of shooting was the so called race track method where the vessel travelled up and down one particular swathe acquiring lines as quickly as possible (4.5 knots) and without waiting for the tides. In all, 2 different swathes were acquired in this way starting with the northeastern half of the programme in February 2009 and finishing with the southwestern half during April 2009. 7.7. POSITIONING DATA QUALITY The quality of the data for the source and receiver positions was of an acceptable standard for all the lines acquired and within the required specifications. Any final NRT derived data presented by the contractor that fell outside the required specifications was re-processed with Sprint satisfactorily. No lines had to be re-acquired as a result of navigation or positioning problems. The in-sea positioning sensors were well maintained and the sea conditions were good throughout, both factors contributing towards the success of the operation. The designated processing system on board was the ORCA/NRT module. There was no dedicated Sprint Navigation Processor on board but some Navigators were experienced users. Ordinarily, processed data was available soon after the end of the line with NRT. Where further processing was required with Sprint the flow was normally completed within a few hours of the end of each line following which the P1/90 had to be re-created from the ORCA database. The contractor ordinarily reprocessed the first 10 lines acquired with Sprint for comparisons.


Afterwards, it was customary to reprocess every fifth line and any lines flagged for Caveats or Reprocess. The quality of the NRT data produced was classified as either Optimal, Caveats or Reprocess. Lines with Optimal results should have required no further processing but that was not necessarily always the case as was discovered when water depth data was found to be missing in some of the P1/90 files. Furthermore, large maximum error-ellipse semi-major axes values (spikes) exceeding specifications in some nodes were also seen in reports classified as Optimal. In both these cases the lines were reprocessed with Sprint. Lines classified with Caveats were usually automatically reprocessed with Sprint. Of a total of 90 line sequences acquired during the operation, one was rejected due a non-positioning problem (source air leak), 80 (93%) had NRT Optimal status, 6 (7%) had Caveats status and there were no lines with Reprocess status. However, 40 line sequences, representing 45% of all acquired, had to be reprocessed due to NRT problems which leaves much to be expected from the next version of the software. The contractor despatched the first line acquired (Sequence 001) to FGPS Ltd, for an independent verification of the quality of the data and the UKOOA file formats. The adjusted total network quality for the whole operation, in terms of the average values for the semi-major axes of the a-posteriori error-ellipse and based on the results of the contractors statistical diagnostics is shown in TABLE 10 below. The data was provided in the usual 1 Sigma level from NRT by the contractor and subsequently converted to 2 Sigma (95% probability level). Average Node Network Error Ellipses

Semi-major Axes (95%) (m)

Centre of Source 2.4 Near Receivers 3.6 Mid Receivers 5.3 Tail Receivers 3.3

TABLE 10 Average Node Network Error Ellipses Semi-major Axes

NRT A Priori Observation SDs Type Observation SD DGPS Fugro SkyFix-XP (E, N) 2.0 m Veripos Ultra (E, N) 2.0 m Veripos Standard Plus (E,N) 2.0 m Fugro MRDGPS (E,N) 3.0 m RGPS All Ranges 2.0 m All Bearings 0.2 Acoustics All Ranges 2.0 Compasses Compasses 02 - 22 0.7 Compasses 01 & 23 0.9 Gyro Gyro Heading 0.0

TABLE 11 NRT A Priori Observation SDs


Source and Streamer Separations The geometry was monitored continuously during production and time series statistics were provided at the end of each line to show the changes during the line. Source and source array separations were stable and consistently good throughout the operation. The same could not be said of the front separations, particularly between Streamers 4 and 5 and 5 and 6 which were invariably low (less than 90% of the nominal separation) after the first 10 line sequences and remained as so until the end of the operation. Furthermore, large variations were experienced between Streamers 5 and 6. The total front end separation between Streamers 1 and 10, however, was always over 90% of the nominal 900 m distance. Some adjustments were attempted but without success and the reasons for the low separations were likely to be a combination of the vessels low average speed (4.5 knots) and currents. The common phenomenon whereby the tail separation between the 2 centre streamers (5 and 6 in this case) is splayed was generally not apparent. In fact, the opposite was occasionally the case where the separation between Streamers 5 and 6 was dangerously low.

Average Source and Source Array Separations (m)

G1-G2 Array 1-2 Array 2-3 Array 3-4 Array 4-550.2 10.7 9.9 10.5 10.8

TABLE 12 Average Source and Source Array Separations

45

46

47

48

49

50

51

52

53

54

55

001

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res SD

's

Source Separations (XLine)

Sequences

Nominal

FIGURE 4 Source Separations (Crossline)

G1_Str1-2 G1_Str2-3 G2_Str1-2 G2_Str2-3

7.07.47.88.28.69.09.49.8

10.210.611.011.411.812.212.6

001

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res

String to String Separations (Xline)

Sequences

Nominal

FIGURE 5 String to String Separations (Inline)


Average Streamer Separations

Near Mid Far S1-S2 99.7 98.9 100.8 S2-S3 101.6 98.6 96.4 S3-S4 102.2 98.5 98.6 S4-S5 88.8 88.2 89.3 S5-S6 84.5 88.4 90.8 S6-S7 98.4 97.4 98.3 S7-S8 101.9 97.7 92.8 S8-S9 104.0 99.6 100.2

S9-S10 101.6 101.9 103.2 S1-S9 882.6 869.2 870.5

TABLE 13 Average Streamer Separations

50

60

70

80

90

100

110

120

130

140

150

15.0

18.0

21.0

24.0

27.0

30.0

33.0

36.0

39.0

42.0

45.0

48.0

51.0

001

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res SD

Streamer Head Separations (XLine)

Sequences FIGURE 6 Streamer Head Separations (Crossline)

Total Near Seps Total Mid Seps Total Far Seps

781

801

821

841

861

881

901

921

941

001

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res

Overall Streamer Separations

Sequences

Nominal

FIGURE 7 Overall Streamer Separations

Inline Offset The overall line by line average for the inline distance between the centre of source and the centre of the near group was 260.85 m. There were no adjustments in this distance during the survey but some variation was seen from line to line.


CofS-CNG

248

250

252

254

256

258

260

262

26400

1

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res

Inline Average CofS to CNG

Sequences

FIGURE 8 Inline Average CofS to CNG

Streamer Rotations and Inline Misclosures Average rotation values were low overall and consistent. There was no indication of significant variation along the lines which would have been indicative of any anomalies. Inline misclosures were also low overall. The inline misclosure for Streamer 7 was slightly larger than the misclosures for the other streamers by approximately 5 m over the average of 4 m. This was attributed by the contractor to a very large log which had been caught on the tailbuoys during the preceding survey and could have lengthened the tail stretch. The streamers had not been recovered between the surveys and consequently there had been no opportunity to change the stretch. FIGURE 9 and FIGURE 10 extracted from the MultiSeis database show the average values for both Rotations and Inline Misclosures:

Rot1 SD1 Rot2 SD2 Rot3 SD3 Rot4 SD4 Rot5 SD5Rot6 SD6 Rot7 SD7 Rot8 SD8 Rot9 SD9 Rot10 SD10

0.00

0.10

-0.10

-0.20

-0.30

-0.40

-0.50

-0.60

-0.700.0

0.2

001

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

degr

ees

SD

Streamer Rotations

Sequences

FIGURE 9 Average Values for Streamer Rotations


Rad1 SD1 Rad2 SD2 Rad3 SD3 Rad4 SD4 Rad5 SD5Rad6 SD6 Rad7 SD7 Rad8 SD8 Rad9 SD9 Rad10 SD10

0.0

2.04.06.0

8.010.0

-2.0-4.0

-6.0-8.0

-10.0

-12.0-14.0 0.0

0.4

0.8

1.2

1.6

2.0

2.4

2.8

3.2

3.6

4.0

4.400

1

004

007

010

013

016

019

023

026

029

032

035

038

041

044

047

050

053

056

059

062

065

068

071

074

077

080

083

086

089

met

res

SD

Streamer Misclosures (Inline Misc')

Sequences

FIGURE 10 Average Values for Streamer Misclosures (Inline Misc)


8. DATA PROCESSING AND QC 8.1. HARDWARE All the acquired data was processed on an SGI (Silicon Graphic Incorporated) suite of computers using Geotrace software.

Mainframe SGI 1 x Main frame SGI Origin 2200 2 x IBM 3592 tape drive - 512 tracks 93 x Dual XEON Linux worker nodes 5 x Dual Xeon Linux NFS file server with 10 TB of Raid disk attached

(one Raid disk replaced with 20 TB of disk) 1 x 24 port gigabit switch

8.2. SOFTWARE

Geotrace Anser Geotrace Data Viewer Geotrace Volume Viewer Geotrace Xanser Geotrace Job Scheduler Geotrace Job Submission Geotrace Job Monitor

8.3. QC PROCESSING FLOW 8.3.1. Reformat Processing Flow

Reformat from disk to Geotrace internal format Apply 3 (18) Hz dB/oct low-cut filter, correct for start of data delay (-50 ms), apply

temporal anti-alias filter and resample to 4 ms Store raw shots to disk Sort data into shot/channel order Group and display near trace for both sources and one streamer Apply 2D geometry Group and display brute stacks and brute CDPs Measure amplitude and display for deep, whole and data time windows, edit out bad

traces 8.3.2. Basic Stack 3D Processing Flow

Read raw shots from Geotrace internal format Read P1/90 navigation data Apply NMO corrections Complete 3D stacking Read stack volume, scale and calculate trace amplitude values Create timeslices as requested

8.3.3. Basic Offset QC Processing Flow Chart

3D - Read raw shots from Geotrace internal format Read P1/90 navigation data Apply and create time offset values, resample to 4 ms Perform a seismic write for offset QC


8.3.4. Basic Means Processing Flow

Generate traces from data amplitudes Resample to 4 ms and scale ensembles Sort data to shot/channel order Perform header values and 3D store for means (shot shot and channel channel)

and cable comparison analysis 8.4. QUALITY CONTROL OUTPUT Via the Champions on board computer network the Client Representative was provided with access to a designated common drive into which, for every sequence, 2 (one from each source) SEG-Y formatted stacks were loaded. The streamers used in the creation of the stacks were rotated sequence by sequence, for example on Sequence 076 Source 1/Streamer1 and Source 2/Streamer 6, on Sequence 077 Source 1/Streamer 2 and Source 2/Streamer 7. In the Client Representatives assigned office a password protected networked computer and a large high-resolution monitor enabled the user to load and analyse the stacks at will using the Geotrace software, no hard copy prints were created which the author was perfectly comfortable with. The only problem was that the Geotrace software was somewhat cumbersome in terms of opening the programme and loading the SEG-Y files for viewing, the slightest error in terms of a keystroke or mouse click saw a message appear indicating that a re-start would be required. The SEG-Y stacks were also transferred to an FTP site established by Geotrace so that BP staff could access the data any time that they wished. Any other large files, crossline stacks for example, were also sent across to the site. Once the first half of the project was complete the author requested sets of timeslices at 250 ms intervals from 2.0 s down to 4.0 s, JPEG files were created and these were passed to BP in the UK as attachments in e-mail directly to Mike Smith. Please find examples of inline and crossline stacks plus timeslices between 1.5 and 4 s in APPENDIX C and APPENDIX D. 8.5. REQUIRED DELIVERABLES

SEG-D field tapes - 2 copies, one of which to be passed to BP Pakistan SEG-Y tapes 1 copy, with shots at 4 ms, geometry attached Hard drive with processed gathers for input to pre-stm (Geotrace Woking) 3D stack of processed data 1 copy 3D migrated stack 1 copy

8.6. PERFORMANCE COMMENTS All the QC processing staff members were sub-contracted in from Geotrace, Woking, United Kingdom and are, along with all their equipment, permanently assigned to the Champion by Wavefield Inseis. All were competent, experienced and fully co-operative with the Author in terms of requests for additional QC products, most of which (timeslices and crossline stacks) were directed through the 2 lead QCs (James Wallace - 25th February to 1st April 2009 and Stuart Rodger 1st April 2009 to the end of the project). There were several hardware issues (one particularly troublesome computer) and one tape drive which failed completely. Fortunately, as only one copy of the SEG-Y tape was required as an end of project deliverable, this was not of any great importance.


Overall the performance of the Geotrace staff was considered to be satisfactory.


9. PERSONNEL LIST

Name Position Nationality On Off Arve Bukkoy Captain Norwegian Feb 25th April 2nd Robert Herland Captain Norwegian April 2nd April 16th Geir Inge Hoyland Chief Officer Norwergian Feb 25th April 2nd Borge Vindenes Chief Officer Norwegian April 2nd April 16th Mervin Fernandez 2nd Officer Philipino Feb 25th April 16th Feilim OMuiri Chief Engineer Irish Feb 25th April 2nd Frode Orten Chief Engineer Norwergian April 2nd April 16th Volodymyr Ponomaryov 1st Engineer Ukrainian Feb 25th April 2nd Jose Emerson 1st Engineer Philipino April 2nd April 16th Vladislavas Vasilevskis 2nd Engineer Lithuanian Feb 25th April 16th Sergey Pecherskiy Electrician Russian Feb 25th April 2nd John Robert Sovik Electrician Norwegian April 2nd April 16th Graham Fisher Party Chief British Feb 25th April 4th Gavin Handbury Party Chief British April 1st April 16th Douglas McLeod Chief Observer Canadian Feb 25th April 1st Anders Langeland Shift Leader Observer Norwegian Feb 25th Mar 31st Gairn McLennan Shift Leader Observer New Zealand April 1st April 16th Robert Reason Shift Leader Observer British Feb 25th April 1st Linden Price Shift Leader Observer British April 1st April 16th Patrick Birt Observer British Feb 27th April 2nd Trond Harald Petterson Observer Norwegian April 1st April 16th Jeremy Hibberd Observer British Feb 27th April 2nd Robert Handal Observer Norwegian April 2nd April 16th Giovani Mariano Observer Philipino Feb 25th April 2nd Darren Pettit Trainee Observer British Feb 25th April 1st Jeremy Harris Chief Navigator British Feb 25th April 2nd George Mladineo Chief Navigator Australian April 2nd April 16th Quantus Ludick Shift Leader Navigator South African Feb 25th April 2nd Kjetil Storetvedt Shift Leader Navigator Norwegian April 1st April 16th Martin Frederiksen Shift Leader Navigator Norwegian April 2nd April 16th Sandine Boudon Shift Leader Navigator French April 2nd April 16th Emir Karcic Navigator Swedish Feb 25th April 1st Tobias Johnson Navigator British April 2nd April 16th Andrew Handspiker Navigator Canadian Feb 25th April 1st Maria De Deuge Navigator Australian April 2nd April 16th Beng Chung Chai Trainee Navigator Malaysian Feb 25th April 2nd John Foss Chief Gun Mechanic Norwegian Feb 25th April 1st Arne Seppola Chief Gun Mechanic Norwegian April 1st April 16th Martin South Shift Leader Mechanic British Feb 25th April 2nd Oystein Foss Shift Leader Mechanic Norwegian April 2nd April 16th Rune Arseth Shift Leader Mechanic Norwegian April 1st April 16th Espen Torgersen Shift Leader Mechanic Norwegian April 2nd April 16th Aristotle Cormero Gun Mechanic Philipino Feb 25th April 1st Igor Mazepa Gun Mechanic Russian Feb 25th April 1st Norbeto Angue Gun Mechanic Philipino Feb 25th April 2nd Faustino Callada Gun Mechanic Philipino April 1st April 16th Christopher Wood Gun Mechanic British April 2nd April 16th Jonathan Nesbitt Trainee Gun Mechanic British Feb 25th April 1st David Stott Medic British Feb 25th April 1st Andy Berry Medic South African April 1st April 16th Peter Huxford HSE Advisor Australian Feb 25th April 2nd Adam Powell HSE Advisor Australian April 1st April 16th James Wallace Chief QC Processor British Feb 25th April 2nd Stuart Rodger Chief QC Processor British April 1st April 16th Mark Seymour QC Data Processor British Feb 25th April 1st Oliver Barroclough QC Data Processor British April 2nd April 16th


Charlotte Royall-Hercoc QC Data Processor British Feb 25th April 1st Frederik Sulle QC Data Processor Indonesian April 2nd April 16th Francisco Figueira QC Data Processor Brazilian April 2nd April 16th M Shah Rome Naval Liaison Officer Pakistani Feb 25th Mar 17th Abdul Razzer Naval Liaison Officer Pakistani March 22nd Apr 17th Muhammad Sheikh Marine Mammal Obs Pakistani Feb 25th Mar 17th Waseem Haider Syed Marine Mammal Obs Pakistani March 22nd April 16th John Granville BP Geophysical Rep British Feb 25th April 16th Eryl Jones BP Navigation Rep British Feb 26th April 16th Patrick Haines BP HSE Rep British Feb 26th April 16th

*Note Only the senior positions on the marine crew are listed, catering staff, junior engineering and deck hands are not.


10. HEALTH, SAFETY AND ENVIRONMENT *NB A detailed report has been submitted by the BP on board HSE advisor Patrick Haines. All of the main seismic companies have well defined HSE management systems in place and Wavefield Inseis are no exception, although of course they are now in the process of integrating theirs into the CGGVeritas Vision database. Overall the crew displayed an excellent approach to all aspects of HSE, from senior management (Party Chiefs, the Captains, the permanent HSE Advisors and Medics) down to the less experienced members of the crew. The project was completed without any incidents, not even a First Aid case being reported and confirmation of that came from BPs HSE Representative Patrick Haines. 10.1. HEALTH The 2 Medics that were aboard the Champion for the duration of the project (Dave Stott and Andy Berry) played a prominent role in the day to day operations, especially when it was confirmed that the Party Chief who left the vessel on the day that the project commenced (Bjorn Henriksen) was subsequently confirmed as having contracted Typhoid whilst in transit through Karachi. A meeting to discuss this issue was specifically called to allay the fears of the crew and to provide advice on the recognition of the symptoms of all tropical diseases in addition to the prevention measures that should always be taken, no matter how short the transit time (in Bjorns case this was only a matter of hours).

10.2. SAFETY The pre-survey brief provided by Mike Smith (BP Sunbury-On-Thames) focused on the BP 8 Golden Rules and the crew readily took the components of the system and wove them into their own safety management system. As one would expect, there was a considerable degree of similarity, e.g. Permit to Work, Energy Isolation, Confined Space Entry, Working at Height, Lifting Operations and Management of Change, whilst obviously driving safety and ground disturbance was not so significant. The crews ability to keep safe operations to the forefront of their thinking was very evident in the manner with which they dealt with 3 occasions when large fishing nets became tangled with the streamer separation ropes and the starboard paravane tow ropes. The planning, execution and recovery from these situations was handled expertly by the senior members of the staff (specifically Party Chief Graham Fisher and Chief Observer Doug McLeod). 10.3. ENVIRONMENTAL ISSUES The crew operated a strict soft start policy on the run-in to the start of each line, there were no requests from the Marine Mammal Observer to terminate a line due to the proximity of any cetaceans. Naturally, no waste materials were disposed of at sea and all 3 nets that were snagged on the streamers were transferred to the shore, the first and second via the Venture G into Karachi and the third when the next opportunity presented itself as it was still being held on board the Champion when the project was completed. A waste segregation policy was in place which required paper, glass, plastics, aluminium, tins and food waste to be disposed of separately. Both the marine and seismic operations also


adhered to strict policies with respect to waste oils and any other hazardous materials that needed to be disposed of.

BP Pakistan/EOM1171/JG/EJ/

Documents

Pitfalls in seismic interpretation