ARAB ACADEMY FOR SCIENCE, T ECHNOLOGY AND MARITIME TRANSPORT

College of Engineering and Technology

SUBSEA PROCESSING THE TODAY AND FUTURE

CHALLENGE by

Ahmed Osama Bedair

A Thesis Submitted in Partial Fulfillment to the Requirements

for the Master's Degree in

Marine Engineering

Under supervision of

Prof. Dr. Mohamed EI NOllr Abdelradi

SEPTEMBER 2006

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AlWI ACADEMY FOR SCIENCE, TEcHNOLOGY AND MARITIME TRANSPORT

College of Engineering and Technology

SUBSEA PROCESSING THE TODAY AND FUTURE

CHALLENGE

by

Ahmed Osama Bedair

A Thesis Subm itted in Partial Fulfillment to the Requirements

for the Master's Degree in

Marine Engineering

Prof. Dr. Mohamed EI Nour Abdelradi Supervisor

Prof. Dr. Abdel-Alim Hashem EI-Sayed Examiner

Dr. Eng. Yousri Elmehd<lwi Examiner

SEPTEMBER 2006

GLOSSARY

ACKNOWLEDGEMENT Pagei

ABSTRACT Page ii

INDEX Page iv

LIST OF TABLES Page vi

LIST OF FIGURES Page vii

NOMENCLATURE Page x

CHAPTER I Page I

CHAPTER 2 Page 10

CHAPTER 3 Page 18

CHAPTER 4 Page 79

CHAPTERS Page 116

CHAPTER 6 Page 122

CHAPTER 7 Page 139

APPENDIX I Page 149

APPENDIX 2 Page 150

APPENDIX 3 Page 151

APPENDIX 4 Page 152

ACKNOWLEDGMENT

I would like to express my sincerest gratitude and

appreciation to Prof. Dr Mohamed EI Nour Abd EI Radi , my

advisor , for his valuate guidance , his support and his

patience in helping me bring this research to completion

ABSTRACT

The booming trend for oil and gas activities is that the production comes from new smaller

and marginal fields including tieback fields to existing infrastructure and also larger fields in

deep and ultra-deep waters.

The industry will be faced with several challenges both technical and economical as these

fields may be complex in nature, tieback distances can be significant and so can the water

depths. The very unstable oil prices have also had a great impact on how these fields must be

developed and operated. More cost effective solutions must be developed to meet the

challenges related to future exploration and production from existing and new fields. All

these new requirements have been the basis and background for the development of sub sea

pressure boosting and processing systems, which include several different technologies to

enhance the production from new and mature fields. Most of these different technology

building blocks are successfully being used by operators

As the potential economic benefits of subsea boosting increases with increased water depths;

the dependence on the operator became less effective and the need to utilize deepwater

equipment became a second to none option. However, the deeper the equipment the more

critical becomes its reliability due to high intervention cost and the long waiting time for the

required vessels.

The dream of subsea processing is to take processing of hydrocarbons to the sea bed and

producing straight to shore instead of depending on expensive surface (onshore or offshore)

facilities. Subsea offers several advantages compared to traditional ways of producing,

processing and transportation from well to onshore terminals. This is made possible today by

many advances in development of key elements such as multi phase pumps, multiphase

meters, and flow lines instrumentation.

The opportunities and possible benefits related to subsea processing technologies are many;

however, there are uncertainties related to the performance of these systems. Significant

development and testing work has been undertaken in the effort of qualifying subsea

processing technologies, and several systems have also been successfully deployed. While

the technology itself is perceived as mature, limited operational experience is available. As a

consequence, the anticipated reliability and risks related to applying these systems are

subject to uncertainty.

Operators hesitate to be the first users of subsea processing technology before the benefits

are fully understood, and currently there is no subsea processing equipment deployed in the

Gulf of Mexico. One of the main concerns for the operators is the uncertainty related to the

operating expenditures and inteIVention costs related to "unforeseen" events and equipment

failures. lnteIVentions and repair operations could potentially be very expensive; long

waiting times for the required inteIVention vessels and resources and complicated

inteIVention operations could be significant economical risk contributors.

Subsea processing equipment is characterized by use of novel technologies or extended

application of existing technologies, increased reliance on remote operations and control

systems and introduces additional complexity in a deepwater subsea production system.

Further, when moving into deeper waters, the uncertainty related to whether "unforeseen"

events would occur increases as the technology is introduced into an operating environment,

which is different compared to shallow water operations. These and other factors have

motivated the interest in a risk assessment and risk comparison of subsea versus surface

based processing.

Objectives and Scope of Study

This study will start initially with an oveIView of the current production systems followed by

a presentation of separation strategies used to manage the onshore fields and offshore

platforms with a focus on strategies and technologies that could be adopted to boost the sub

sea processing and in particular separation technologies. The study will then follow by brief

presentation of challenges related to process/flow assurance and other operability issues

followed by a detailed risk comparison for subsea processing versus surface processing,

finally the study will then conclude with a case study for the Rosetta / Egypt, Simian and

Sapphire field that is being developed recently in a very aggressive and promising manner.

III

INDEX

CHAPTER I OIL AND GAS INDUST RY

1.1 OIL AND GAS PRODUCTION SYSTEMS

CHAPTER 2 REMOVAL OF LIQUIDS AND SOLJUS FROM GAS STREAM AT ONSHORE PLANTS

2. 1 REMOVAL MECHANISMS 10

2.2 SEPARATION TECHNOLOGIES 12

2.2.1 LIQUJU/GAS CAOLESCERS 12

2.2.2 THREE PHASE ROTARY SEPARATOR TURBINE 14

2.2.3 SPIRA FLOW DEMISTING CYCLONE 15

CHAPTER 3 SUBSEA PROCESSING

3.1 REMOVAL OF LIQUJUS AN D SOLI DS FROM OIUGAS IS STREAM AT SUBSEA PROCESS PLANTS

3.1.1 DOWNHOLE OIL I GAS SEPARATOR IS

3.1.2 SUB SEA SEPARATION AND INJ ECTION SYSTEM (SUBSIS 20 CONCEP1)

3.1.3 COMPACT SUB SEA SEPARATOR WITH INEGRATED 23 SAND MANAGEMENT SYSTEM

3.1.4 ULTRADEE P WATER-GRAYITY DASED SEPARATOR 25

3.1.5 TWISTER SUB SEA SEPARATION MODEL 30

3.2 SUBSEA PIG LAUNCHER 32

3.3 TRANSFER PUMPS 35

3.4 DEHYDRATION SYSTEMS 40

3.5 HEATING OF DEEPWATER FLOW LINES 47

3.6 POWER SUPPLY AND CONTROL SYSTEM 52

3.7 SUBSEA MAN IFOLDS 63

3.S SUBSEA LEAKAGE MONITOR 72

3.9 SUBSEA FLOWMETERS 74

CHAPTER 4 RISK COMPARISON SUBSEA VS SURFACE PROCESSING

4.1 DEEP WATER CHALLENGES 79

4.2 SUBSEA PROCESSING TECHNOLOGY 84

4.3 RISK IDENTIFICATION 95

4.4 RISK CAMPARISON 105

CHAPTERS DEEPWATER INSTALLATION OF SUBSEA HARDWARE

5.1 DEEPWATER INSTALLATION ISSUES 116

5.2 THE CHALLENGES 116

CHAPTER 6 CASE STUDY

6.1 PROJECT INFORMATION 122

6.2 DESIGN AND INSTALLATION ASPECTS 123

6.3 EXISTING SUB SEA FACILITIES - DESCRIPTION OF THE 128 FIELD

6.4 EXISTING EQUIPMENT· ONSHORE FACILITIES 128

6.5 ASSUMPTIONS 129

6.6 SUBSEA PLANT 129

6.7 RISK COMPARISON 130

CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS 139

REFERENCES 147

v

Table I

Table2

Table3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table II

LIST OF TABLES

Types of liquid/gas separators

Retrofits summary

Overview of the project activities

Summary of HAZID review of subsea processing

Risk values for the base case

Breakdown of gas related process ri sks

Summaries of the subsea processing risks

Base case - Annual frequency of hydrocarbon release

Subsea processing - Annual frequency of hydrocarbon release

Onshore Faci lity - Equipment summary

Indicative cost comparison for surface equipment VS subsea

equipment

VI

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure II

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

LIST OF FIGURES

Offshore production systems

Typical fixed platforms

Typical compliant tower

Semi submersible platfonn

Typical floating production unites

Tension leg platform

Examples of spar platforms

Subsea processing (multiple wells)

Global subsea total expenditure 2004 - 2008

Global subsea expenditure (%) 2004 • 2008

Coalescer cut-away View

Aerosol sizes

Three-phase rotary Separators (RST3)

Spiraflow cyclones

Typical in-l ine, bulk gas: liquid downhole separator

Schematic SUBSIS unite

SUBS IS unite ready for installation

New subsea separator concept

Subsea separator as part of subsea system

Full-scale separator installed in test rig

Production with and without subsea separation

Figure 22

Figure 23

Figure 24

Figure 2S

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 3S

Figure 36

Figure 37

Figure 38

Figure 39

Figure 40

Figure 41

Figure 42

Figure 43

Figure 44

Hydrate-formation curve

Deepwater gravity separator

Typica1 Twister sub sea module with up to six twister tubes

mounted vertically around a vertical liquid degassing vessel

Modular subsea gas processing system including a Twister

debydration unit

Subsea pig launcher overall assembly

injection pump cross section drawing

Multiphase pump

Deep Booster system

Deep separation module pump

ceo Compact cyclonic degasser

ROY operation on the D1PSIS module by 1500 m water depth

Pump manifold and control system

Typical XLPE power cable cross section

Control umbilical reel spooling at factory

NAXYS subsea leakage monitor

Wet gas flowmeter

Chocke bridge versions - MPFM CBV

Pressure boosting of the well

The Framo subsea multi phase booster pump

Schematic showing how the V ASP system works

The Subsea waler separator - Troll Pilot

Flow assurance risks for a typical deepwater development

Offshore field general lay out

r igur. 45

figure 46

Figure 47

Figure 48

Figure 49

Figure 50

Figure 5 1

PLEM (pipeline end manifold)

10" PLET (pipeline end terminal)

4 - Slot manifold horizontal at 106m water depth

4 - Slot manifold horizontal at 308m water depth

6 - Slot deepewater manifold

4 - Slot manifold with high pressure high temperature

2 - Slot overtrawlable manifold at 260 water depth

IX

hfpd

CAPEX

CT

CVC

DAPS

DGS

DGWS

DIPSlS

DMC

DOWS

ESP

FEED

FP

FPSO

GLCC

GOR

HAZID

HPIHT

HSE

lRPA

LDA

LLCC

NOMENCLATURES

Barrel fluid per day

Capital expenditure

Compliant tower

Cameron Vertica l Connector

Dual action pumping system

Downhole gravity segregation

Downhole gas I water separator

Deep integrated production, separation and injection system

Deep water managing contractor

Downhole oil I water separator

Encapsulated subsea pump

Front end engineering and design

Fixed platfonn

Floating production, storage and amoading system

Gas liquid cylindrical cyclone

Gas I Oil ratio

Hazard identification

High pressure / High temperature

Health , safety and environment

Individual risk per annum

Low dosage additives

Liquid liquid cylindrical cyclone

MARS

MEG

MPFM

MTBF

MW

NPV

OPEX

PLEM

PLET

QRA

ROV

RSTJ

sev

SDA

SEPDIS

SPL

SUBSIS

SWL

TLP

TDU

UTB

VASI'

ves

VDF

we

Multi application re- injection system

Mono ethylene glycol

Multi phase flowmeter

Mean time between failures

Mega watt

Net present value

Operational expenditure

Pipeline end manifold

Pipeline end terminal

Quantitative risk assessment

Remote operated vehicle

Three phases rotary separator

Subsea control valve

Subsea distribution assembly

Subsea electrical power distribution system

Subsea pig launcher

Subsea separation and injection system

Safe working load

Tension leg platform

Tool deployment unit

Umbil ical distribution box

Vertical annular separation and pumping system

Vertical connection system

Variable frequency drive

Water content

WGM

XLPE

Wet gas flowmeter

High vo ltage insulated cable

XII