Remediation of Severely Damaged Wells Using Mesophase

ABSTRACTchemical conditions can vary greatly depending on the applica-tion. As a consequence, robust, optimized formulations arenecessary, and validation testing is required, to determine theefficacy of a mesophase for a specific application, i.e., OBMdisplacement/cleanup and removal of formation damage inopen hole and cased hole wells.

This article presents a technical overview of mesophasetechnology and field applications that demonstrate the efficiencyof mesophase fluids for removing synthetic OBM debris andfilter cakes, reducing near wellbore damage and improvingwell productivity.

INTRODUCTION

Understanding and minimizing formation damage is one of themajor factors that must be considered in designing reservoirdrilling fluid. There are no fluids today that can guarantee zerodamage to the reservoir. Consequently, the quest is to design afluid system capable of minimizing permeability impairment.The extent of damage can be potentially severe if drilling mudis not effectively displaced and cleaned out from the wellboreusing the appropriate completion fluid after the drilling phase.The fine solid contents of the mud can migrate and penetratedeep into perforations or the open hole rock matrix, limitinghydrocarbon flow. The difficult-to-clean internal and externalmud cake deposited by nonaqueous drill-in fluid (DIF) alsoposes a significant risk to optimal production, especially wherenear wellbore wettability is already altered.

Many changes and improvements have been made in recentyears to the design of DIFs to deliver wells that are completedas open hole; however, formation damage still exists in most ofthe wells drilled. In addition to poorly designed DIF systems,other major factors influencing the degree of residual damagefrom oil-based mud (OBM) include variations in reservoirquality, permeability, pore size distribution, lithology, reservoirdepletion and the complexity of the completion. Further damagemay also be caused by poorly designed stimulation chemicals1.

Accepting the fact that even a properly designed fluid systemhas some negative effect on production, however small, plan-ning and laboratory testing can help to minimize this effect byremoving a significant portion of the damage before the pro-duction phase. In open hole completions, removal of the OBM

Formation damage is a byproduct of the drilling, completionand production process, and is attributed to many factors. Inopen hole and cased hole wells, hydrocarbon flow may be im-peded by various damage mechanisms caused by drilling andcompletion fluids, i.e., in situ emulsions, water block, organicdeposition and oily debris left downhole.

Mesophase fluids have been successfully developed to effec-tively resolve the persistent problem of near wellbore damage.The physical and chemical properties of the mesophase sys-tems include rapid oil solubilization, high diffusion coefficientsthrough porous media, and the reduction of interfacial tensionbetween organic and aqueous phases to near zero, makingthem excellent candidates for removing formation damage.The chemistry of mesophase fluids, in particular, makes thesystems excellent choices for synthetic or oil-based mud(OBM) displacements in casing and for OBM filter cakecleanup in open hole completion applications.

Mesophase fluids are thermodynamically stable, opticallytransparent solutions composed of two immiscible fluids. Theydiffer from ordinary emulsions because they can be preparedwith little or no mechanical energy input. They are typicallycomposed of a nonpolar (or oil) phase, an aqueous phase, sur-factant(s) and an optional cosurfactant. Depending on howthey are formulated, they can exist in a single-phase or three-phase system; in the latter, the middle-phase microemulsion isin equilibrium with the excess water and oil. The formulationcharacteristics, the phase type, and ultimately, the cleaning effi-ciency of a microemulsion are dictated by the hydrophilic-lipophilic balance between the surfactant(s) and the physico-chemical environment. The microemulsions described in thestudy are single-phase systems, where oil and water are co-sol-ubilized by the surfactant(s) and cosurfactants. The water-oilinterface has a zero or near zero curvature, indicative of the bi-continuous phase geometry that produces very low interfacialtension and the rapid solubilization of oil upon contact.

The formation of a mesophase does not ensure the fluid willsolubilize oil effectively and so leave surfaces water-wet. Themesophase behavior and cleaning efficiency can be altered bysalinity, surfactant, cosurfactant, oil type, temperature andparticulates. No two wells are identical, and the physical and

Remediation of Severely Damaged WellsUsing Mesophase Technology: CaseHistories in Saudi Arabia

Authors: Ajay Kumar V. Addagalla, Balraj A. Kosandar, Ishaq G. Lawal, Prakash B. Jadhav, Aqeel Imran, Mohamed S. El-Araby, Qassam R. Al-Saqer, Adel A. Al-Ansari, Rafael M. Pino Rojas, Ahmed E. Gadalla and Tulio D. Olivares

SPRING 2016 SAUDI ARAMCO JOURNAL OF TECHNOLOGY

filter cake debris can be done either in the completion stage orin the remediation stage. Both approaches have proven suc-cessful in restoring the production potential in several areas.

The primary causes for formation damage are:

• Type of drilling fluid used.

• Bridging package selection.

• Overloading of emulsifiers.

• Fluid losses while drilling.

• Non-acid soluble solids, such as fluid loss control agents and viscosifiers.

• Solids residue invasion.

• Completion fluid incompatibility.

• Reservoir incompatibility.

A relatively new solution has emerged for removing theOBM filter cake in open hole completions, called microemul-sion technology2. This technology has been applied success-fully in most of the areas where hydrocarbon flow wasstopped or reduced by emulsion blockage from fluid-fluid in-compatibility issues. A careful design of the fluid to ensure itpossesses very low — nearly zero — interfacial tension proper-ties with the damaging fluid facilitates the designed fluid’s mo-bility to zones of interest in the rock matrix. This ultra-lowinterfacial tension phenomenon significantly increases the dif-fusion rate of the treatment fluid, thereby improving the rateof solubilization of the damaging oil fraction and the eventualdestabilization of emulsion block. As oil is solubilized and re-moved from the near wellbore, completion screens and therock matrix become water-wet, and residual solids are dis-persed and mobilized. In addition to the removal of oil fromthe surfaces, organic acids help to remove the acid soluble ma-terials and further reduce the wellbore damage. This articlepresents details of the laboratory results and field applicationsbased on this specialized surfactant system technology thatdemonstrate its ability to remove various types of damage andso significantly increase hydrocarbon production. Mechanicalagitation is typically not required — or suggested — becausethe fluid has ultra-low/near zero interfacial tension and highdiffusion rates3.

Microemulsion Technology

The mesophase surfactant fluid is designed to form a micro-emulsion system comprising a nonpolar phase (oil), an aqueousphase (brine and acid), surfactants and cosurfactants (op-tional). The microemulsions described are single-phase fluids— unlike OBM — and comprise two immiscible fluids, whichare transparent and thermodynamically stable, with ultra-lowinterfacial tension. These fluids differ from a normal emulsionsystem — either oil-in-water or water-in-oil — which requires

SAUDI ARAMCO JOURNAL OF TECHNOLOGY SPRING 2016

immense mechanical and thermal energy to blend and stabilizethe emulsion with special emulsifying surfactants. The single-phase microemulsion fluid requires little or no mechanical en-ergy because of its ultra-low free energy, giving it a self-diffusingproperty, and it is thermodynamically stable. In microemul-sion, the hydrophilic group as a head and the hydro-phobicgroup as a tail are constantly engaged in a bicontinuous dance.These fluids have a high self-diffusion co-efficient, one that isclose to the neat fluid used in the formulation, producing a veryhigh diffusion rate when they are used as remediation fluids4.Figures 1 and 2 show emulsion and microemulsion when observed with the naked eye.

The formation of microemulsion does not ensure the fluidwill solubilize the oil effectively and so leave surfaces water-wet. The microemulsion phase behavior and detergency effec-tiveness also can be altered by salinity, surfactant choice,cosurfactant, oil type, temperature and particulates. No twowells are identical, and the physical and chemical conditionscan vary depending on the application. As a consequence, ro-bust but customized formulations are required, accompaniedby validation testing to determine the effectiveness and effi-ciency of a microemulsion for the specific application. Poten-tial applications include OBM displacement, mud cakeremoval/cleanup and remediation of formation damage2.

Design Criteria

Base Oil: To design the mesophase surfactant fluid, the type of

Fig. 1. OBM (water-in-oil emulsion).

• Reservoir Permeability: 1 to 4 darcy

• BHT: 185 °F to 200 °F

• Differential Pressure While Drilling: 500 psi to 1,000psi — drilling fluid density of 80 pounds per cubic foot(PCF)

Cake Removal Test

An American Petroleum Institute (API) high-pressure/high tem-perature (HPHT) heating jacket and fluid loss cell were used toevaluate the removal of filter cake left by an OBM DIF. An 80PCF sample of field mud was collected to build the initial filtercake. An aloxite disc with nominal 55 µm pore openings wasplaced into the filtration cell. The lab prepared OBM DIF wasthen placed into the cell. The cell was placed in the heatedjacket at the required temperature, and near the top and bot-tom stems. The top stem valve was opened, and 100 psi wasapplied until the test temperature was reached. The pressurewas increased, and the lower valve was opened, enabling fluid(filtrate) to pass into a graduated cylinder. Figure 3 shows thefiltrate collected, and Fig. 4 shows the filter cake, which wasbuilt up for 3 hours with a 500 psi differential pressure andthen carefully removed before treatment.

Preparing Mesophase Surfactant Fluid Soak

The mesophase surfactant fluid soak ingredients were added inthe following order: water, brine, surfactant(s), acid and addi-tional cosurfactant. They were then mixed gently with a mag-netic stirrer. A series of mesophase surfactant fluid formulationswas used to evaluate the delay time prior to field use. Table 1provides the details of the mesophase surfactant fluid formula-tions used to treat the 80 PCF OBM DIF mud used for drillingthe Khafji reservoir.

Formulation Components

The recommended formulation for the cleanup jobs in thesewells includes:

Brine: Provides the density required for the system. The systemis flexible to accommodate various salt choices, includingsodium chloride, calcium chloride, calcium bromide, andsodium or potassium formate.

Primary Mesophase Surfactant: Destabilizes emulsion and sol-ubilizes oil fractions. The emulsion to be removed blocks theoil passage pore throats, leading to low or zero production.The surfactant selection primarily depends on the type of baseoil and the BHT.

Corrosion Inhibitor: Helps mitigate the corrosion of inflowcontrol devices (ICDs) and the tubular area that that is exposed

base oil plays a crucial role in the selection of the surfactant.

Bottom-hole Temperature (BHT): Mesophase surfactant fluidcan be designed for a wide range of temperatures; however, thetemperature must be known beforehand to enable the labora-tory to formulate a robust and efficient system.

Density: The desired density of the mesophase surfactant fluidsoak solution dictates the brine type to be used to formulatethe system.

LABORATORY EVALUATION AND CUSTOMIZATION

The mesophase surfactant fluid must be designed based on thefield conditions, reservoir characteristics, DIF properties, com-pletion fluids compatibility with formation fluids and tempera-ture conditions. A series of tests was conducted on laboratorymixed, oil-based DIFs using mesophase surfactant fluid solutionsto evaluate their cleanup efficiency. The cleanup was intended tosolubilize the oil and emulsions, fluidize the filter cake into asingle phase, dissolve the acid soluble particles, and render thedrill solids and formation rock water-wet. The mesophase sur-factant fluid was designed to delay its reaction times to delivera uniform treatment to the entire wellbore in 6 to 8 hours.

Mesophase Surfactant Fluid Design for the Khafji Reservoir

• Type of Formation: Sandstone

Fig. 2. Single-phase microemulsion.


to the fluid. The inhibitor does not contain any aromatic sol-vents, quaternaries or heavy metals. Laboratory test resultsshow the addition of this corrosion inhibitor reduces the corro-sion rates to acceptable levels as per the API.

Secondary Mesophase Cosurfactant: Helps mobilize the solidsthat stick to the surface of the wellbore so as to produce water-wet surfaces. The other advantage of adding a cosurfactant isthat it reduces the interfacial tension of the system to nearlyzero, enabling the fluid to penetrate deeper into the formation.

Organic Acid: Acidizable solids, e.g., calcium carbonate, in themud cake and in the formation are solubilized efficiently aftertheir dislodgment and water-wetting by the surfactants, all in asingle run.

Filter Cake Cleaning

After the filter cake was deposited, the 100 ml soak solutionwas carefully poured into the HPHT cell — so as not to dis-turb the integrity of the filter cake. The HPHT cell was placedin the heating jacket and heated to 200 °F, and 200 psi of pres-sure was applied to the cell. The first 50 ml collected checkedthe designed delay time. The cell was refilled with another 50ml of mesophase surfactant fluid. The lower valve was closedfor 16 hours to check for complete water wettability.

Soaking Test

The purpose of the soaking test was to determine the amountof time it takes for the mesophase surfactant fluid solution topass through a filter cake — referred to as “delay time.” Thetime reflects how long it would take the mesophase surfactantfluid solution to create a path through such a filter cake duringcompletion and begin experiencing completion fluid losses.The test was run at a BHT of 200 °F for the Khafji reservoirdesign. The volume of soak solution collected was recorded asa function of time. The initial 100 mL of soak solution wasplaced on top of the filter cake, and the test ended when thetotal volume was collected from the bottom stem valve.

The second purpose of the test was to determine the abilityof the mesophase surfactant fluid soak solution to water-wetthe solids from the OBM filter cake. The test used the sameHPHT cell in which the filter cake was built, enabling contactbetween the solution and the cake to occur using 200 psi ofapplied pressure. After the required amount of soak time at

Fig. 3. The first 50 ml of filtrate after treatment.

Fig. 4. Filter cake before treatment.

Product Concentration

Brine 63% to 77%

Primary Mesophase Surfactant Fluid 15% to 21%

Corrosion Inhibitor 0.5% to 1%

Mesophase Cosurfactant 2.5% to 5%

Organic Acid 5% to 15%

T

Table 1. Laboratory customized mesophase surfactant fluid formulation forsandstone reservoirs (Source: Baker Hughes Dhahran R&D Center laboratory)


200 °F, a water-wetting evaluation was conducted. The cakewas dispersed in fresh water, and the behavior of the solids insuspension and at the surface of the disk was observed. Figures5 and 6 present the results.

Compatibility Testing

Based on the reservoir information, a series of mesophase sur-factant fluid formulas was customized to ensure improved wet-tability and the removal of wellbore emulsion/water blockagesand filter cake components. Laboratory results showed a reac-tion delay of 6 to 8 hours was needed to improve operation efficiency and perform uniform cleanup. Figure 7 shows con-firmation of the mesophase surfactant fluid’s compatibilitywith brine, with no phase separation observed.

A compatibility test was performed between the crude oilfrom an existing well in the same field and the mesophase for-mulation optimized for use in this job. Both samples weretaken and heated up to 150 °F separately. Equal amounts(50:50) of solution were poured into a 100 ml beaker, one af-ter another, and agitated vigorously with a glass rod for 5 min-utes to ensure good miscibility. The cylinder was placed atstable room temperature in a static position and observed forseparation or any emulsion/precipitate formation. The goal ofthe test was to determine how fast separation occurred withoutany emulsion/precipitate formation; 100% phase separation

should be observed to confirm the mesophase surfactant fluidcompatibility with the reservoir hydrocarbon.

Table 2 shows the amount of separation with respect totime. The percent breakout is calculated as: Vs/Vt, where Vs isthe volume of fluid separated and Vt is the total volume in thebeaker. Figures 8 and 9 show the behavior of the two fluids,crude oil and mesophase surfactant fluid, at the initial and fi-nal stages, respectively, of their mixing together.

Contact Angle

The wettability of the reservoir is a very important parameterthat affects oil-water relative permeabilities, fluid movementand solids mobilization. The contact angle of a water dropleton a surface before and after the surface’s exposure to theOBM and mesophase surfactant fluid is an important parame-ter to consider when validating wettability. These tests were

Fig. 5. Wettability evaluation of solids in suspension after mesophase surfactantfluid soak.

Fig. 6. Wettability evaluation of solids at the disk surface after mesophasesurfactant fluid treatment.

Fig. 7. Mesophase surfactant fluid compatibility with brine.


used to evaluate the ability of a spacer or remediation fluid tochange the surface wettability from oil-wet to water-wet. Con-firmation of a water-wet surface was achieved by leaving a wa-ter droplet on the surface of the glass to observe the contactangle. The lower the contact angle, the greater degree of water-

wettability on the surface. Figures 10 and 11 shows the con-tact angle of the water drop before and after treatment of theglass surface.

Time (Min) Separation (vol%)

0 0

1 4

2 10

3 20

4 44

5 76

8 96

10 98

15 100

20 100

25 100

30 100

60 100

Table 2. Phase separation (%) with respect to time in a test of the mesophasesurfactant fluid compatibility with the reservoir hydrocarbon

Fig. 8. Fluids after agitation at time t = 0 hr.

Fig. 9. Fluids after agitation at time t = 1 hr.

Fig. 10. Droplet contact angle on glass treated with OBM.


FIELD APPLICATION

Many wells in Saudi Arabia have open hole completions be-cause it is nearly impossible to perforate/fracture thousands offeet. Production rates or injection rates often fail to meet theinitial targets due to OBM damage. To demonstrate the per-formance of the formulated mesophase surfactant fluid blendin the field applications, two case histories are presented. InCase 1, a newly drilled well that was drilled with OBM didn’tproduce during the initial well flow testing right after thedrilling was finished. In Case 2, the well was drilled with OBMand shut-in for some time. No wellbore remediation systemswere used to treat the OBM damage at either well after drillingwas completed.

Case 1: New Well Remediation

This well was drilled with OBM at 80 PCF using calcium car-bonate as a weighting agent; the OBM formulation and aver-age parameters are given in Tables 3 and 4, respectively. Thewell did not flow back after drilling, so completion work wasperformed — including flow back. The reservoir was believedto be plugged with the solid particles and severely damaged bythe drilling mud. Selected based on previous experience in thearea, the mesophase surfactant fluid was pumped in, using acoiled tubing (CT) unit because the rig had already moved on

to its next location. The well’s ICD screen completion em-ployed six packers in the reservoir. After the CT unit riggedup, the mesophase surfactant fluid was pumped into each sec-tion of the reservoir individually and was squeezed into theformation. The mesophase surfactant fluid package was left tosoak for 24 hours in the formation. Table 5 shows the wellconditions recorded before the job.

When the production section had been drilled to the targetdepth, roller reamer trips were performed to eliminate any re-strictions on placing the ICD screens. The ICD screens weredesigned using electrical log information that identified themost productive zones. The screens were run in hole to the tar-get depth, and the following procedures were followed in con-ducting the near wellbore damage remediation:

• The liner hanger was placed and set.

Fig. 11. Droplet contact angle on glass treated with OBM and mesophasesurfactant fluid.

Product Concentration Units

Base Oil As Required lb/bbl

Primary Emulsifi er 8.0 lb/bbl

Secondary Emulsifi er 2.0 lb/bbl

Lime 6.0 lb/bbl

Fluid Loss Controlling Agent 6.0 lb/bbl

Water As Required lb/bbl

Calcium Chloride As Required lb/bbl

Clay Viscosifi er 8.0 lb/bbl

Low-End Rheology Modifi er 1.0 lb/bbl

Assorted Calcium Carbonate 135 lb/bbl

T

Table 3. Formulation of OBM used to drill the section

Property Range Units

Mud Weight 80 PCF

PV 28 to 35 cP

YP 20 to 28 lb/100 ft2

Gels (10 sec/10 min) 8 to 10/12 to 18 lb/100 ft2

6 RPM 10 to 12 lb/100 ft2

HPHT at 250 °F/500 psi < 3.0 ml

ES > 400 Volts

Chlorides 200K to 250K mg/lit

Excess Lime ± 2.0 lb

OWR 80/20 –

T

Table 4. Average OBM parameters maintained during drilling


• The well was displaced to clear brine using custom-designed spacers.

• The top packer was set.

• The well was flowed back, and the well didn’t produceanything.

• The cleanup fluid system was mixed in a batch mixerand pumped through the CT unit, to improveoperational efficiency and to avoid contamination.

• The customized fluid system — designed to produce insitu mesophase surfactant fluid reactions — waspumped using modeled flow rates to minimize OBMfilter cake erosion and minimize fluid losses.

• The mesophase surfactant fluid system soaked for 24hours.

Case 2: Old Well Remediation

This well was drilled as an 8½” hole in 2009 and completedwith 5½” ICD screens with seven constrictors and six swellpackers on the horizontal section. The well was flared andcleaned with 99% oil at 550 psi flowing wellhead pressure.When the well was first placed on production, it could notflow against the back pressure of 400 psig. The well was shut-in (dead). An X-ray diffraction analysis revealed that thesludge collected during the nitrogen lifting operation washeavy with solids and calcium carbonate. Table 6 shows thewell conditions recorded after the job.

• The CT was rigged up with a jetting assembly and runin hole to total depth (TD) — a jetting assembly withrotating/spinning heads is recommended.

• At TD, the open hole volume was displaced to base oilwhile pulling upwards, jetting the lower completionwith the oil. This can be repeated two or more times.

• With the jetting tool back on-bottom, the open holevolume was displaced to mesophase surfactant fluid bypumping 5 bbl to 10 bbl ahead, then pulling upwardsand jetting with the fluid.

• The tool was run back to the bottom, pumping

mesophase surfactant fluid — at a minimum rate — andthe displacement/jetting was repeated from the bottomupwards.

• Some volume of mesophase surfactant fluid wassqueezed to pass through the screens into the variouscompartments.

• The tool was pulled out of hole, and operations pausedfor the required soak time before flowing the well —typically ~24 hours.

Figure 12 shows the production levels for both wells beforeand after treatment with the mesophase surfactant fluid pack-age. Both wells showed great improvement in production.

CONCLUSIONS

1. The laboratory tests used to qualify the mesophasesurfactant fluid package to remove the near wellboredamage in open hole wells showed that it worked. Theresults indicate that the formation damage can be removed,thereby enhancing the hydrocarbon flow.

2. Laboratory studies demonstrated that the designedsurfactant package does not have any compatibility issuesand can solubilize oil and remove any in situ emulsionblockage.

3. The selected mesophase surfactant fluid package used forthe open hole remediation was effective in the fieldapplications.

Reservoir Name Khafji Main Sand

Temperature Range 160 ºF

Formation Type Sandstone

Open Hole Size 8½”

Open Hole Length 3,350 ft

Completion Type 5½” ICD Screens

Completion Brine Sodium Chloride

T Table 5. Well conditions recorded before the new well remediation (Case 1)

Reservoir Name Khafji Sand

Temperature Range 160 ºF

Formation Type Sandstone

Open Hole Size 8½”

Open Hole Length 3,300 ft

Completion Type 5½” ICD Screens

Completion Brine Sodium Chloride

T Table 6. Well conditions recorded after the job

Fig. 12. The performance of Well-A and Well-B before and after treatment withthe mesophase surfactant fluid package.


4. The field case histories prove:

• Delayed reaction helps in removing the filter cakeuniformly, thereby enabling the reservoir to flow at itsmaximum potential.

• Induced emulsion damage in the open hole can beremoved using this mesophase surfactant fluidsurfactant package.

• The mesophase surfactant fluid package can performeffectively in mobilizing the solids and water-wetting thenear wellbore area.

• This mesophase surfactant fluid package can removeblockage caused by solids and enable hydrocarbon flow.

5. Field case studies show that the mesophase surfactant fluidcan restore production in old, damaged wells in maturefields and is an effective alternative to new well orsidetrack drilling.

ACKNOWLEDGMENTS

The authors wish to thank the management of Baker Hughesand Saudi Aramco for their support and permission to publishthis article. We are also grateful for the contribution and sup-port provided by Saudi Aramco’s Drilling Technical Department.

This article was presented at the SPE/IADC Middle EastDrilling Technology Conference and Exhibition, Abu Dhabi,UAE, January 26-28, 2016.

REFERENCES

1. Berge, J.J., El Sherbeny, W.I.A., Quintero, L. and Jones,T.A.: “Using Microemulsion Technology to Remove Oil-based Mud in Wellbore Displacement and RemediationApplications,” SPE paper 150237, presented at the NorthAfrica Technical Conference and Exhibition, Cairo, Egypt,February 20-22, 2012.

2. El Sherbeny, W.I.A., Bakr, D., Quintero, L., Jones, T.A.,Anwar, M. and Moussa, D.: “New Insights into SurfactantSystem Designs to Increase Hydrocarbon Production,” SPEpaper 164273, presented at the SPE Middle East Oil andGas Show and Conference, Manama, Bahrain, March 10-13, 2013.

3. Christian, C.F., Quintero, L., Clark, D.E. and Jones, T.A.:“Production Enhancement of Cased Hole Wells UsingMesophase Fluids,” SPE paper 126062, presented at theSPE Saudi Arabia Section Technical Symposium andExhibition, al-Khobar, Saudi Arabia, May 9-11, 2009.

4. Olsson, U. and Lindman, B.: “Uni- and BicontinuousMicroemulsions,” in The Structure, Dynamics andEquilibrium Properties of Colloidal Systems, Vol. 324, eds.

D.M. Bloor and E. Wyn-Jones, Kluwer AcademicPublishers, The Netherlands, 1990, pp. 233-242.

BIOGRAPHIES

Ajay Kumar V. Addagalla is currentlyworking as the Technical Manager forDrilling and Completion at BakerHughes for the North Arabian GulfGeomarket. He has more than 8 yearsof oil field experience and has servedin various positions, including

Engineering and Sales Manager. Ajay’s areas of expertiseinclude drill-in fluids, completion fluids and near wellboredamage remediation techniques.

He received his B.Tech. degree in Chemical Engineeringfrom Jawaharlal Nehru Technical University, Hyderabad,India, and his M.Res. degree in Petroleum andEnvironmental Engineering from University of Nottingham,Nottingham, U.K.

Balraj A. Kosandar is currentlyworking as a Product Line Manager atBaker Hughes for the North ArabianGulf Geomarket. He has more than 20years of oil field experience and hasserved in various positions inEngineering, Sales and Operations.

Balraj has worked in more than eight countries. He received his M.S. degree in Petroleum Technology

from Nowrosjee Wadia College, Pune, India.

Ishaq G. Lawal is currently workingas an Operations Manager at BakerHughes for the North Arabian GulfGeomarket. He started his career as aLab Technician and moved intoOperations, and then Sales, beforecoming to Saudi Arabia in his current

position. Lawal has more than 15 years of experience inthe oil industry.

He received his B.S. degree in Petroleum Engineeringfrom the University of Ibadan, Ibadan, Nigeria, and hisMBA from the University of Liverpool, Liverpool, U.K.

Prakash B. Jadhav is currentlyworking as an Operations Manager atBaker Hughes for the North ArabianGulf Geomarket. He has more than 10years of experience in the oil industry,working in more than five countries,and served in various positions in

Operations and Sales before coming to Saudi Arabia in hiscurrent position.

He received his B.Tech. degree in Chemical Engineeringfrom Dr. Babasaheb Ambedkar Marathwada University,Aurangabad, India.


Aqeel Imran is currently working as aBusiness Development Manager atBaker Hughes for the North ArabianGulf Geomarket. He has more than 20years of experience in the oil industryand has served in various positions.Aqeel has worked in more than eight

countries. His last role before coming to Saudi Arabia wasas the Product Line Manager for the Iraq Gulf and IndiaGeomarket.

Aqeel received his M.S. degree in Petroleum Geologyfrom the University of Karachi, Pakistan.

Mohamed S. El-Araby is currentlyworking as a Sales Manager at BakerHughes for the North Arabian GulfGeomarket. He has more than 20years of experience in the oil industryand has served in various positions,including Operations. Before assuming

his current position, Mohamed was the Operations Leadfor the Northern Area and offshore Saudi Arabia.

He received his B.S. degree in Petroleum Geology fromSouth Valley University, Qena, Egypt.

Adel A. Al-Ansari is a Drilling FluidsSpecialist in Saudi Aramco’s Research& Development Center. His areas ofinterest include designing the drilling,completion and workover fluids,promoting protection of corporateassets, including reservoir protection,

by introducing less damaging drill-in fluids, monitoringdrilling operations, reviewing daily reports and providingconsultations. Adel is conducting applied research projectsto resolve problems associated with field operations and toprovide a foundation in transferring and implementing thelatest drilling and completion fluid technology in SaudiAramco fields. He is involved in the development ofproduct specifications and laboratory test procedures andthe QA/QC management program for drilling fluidadditives.

Adel is a member of the American Petroleum Institute(API) and the Society of Petroleum Engineers (SPE).

He received two B.S. degrees, the first in IndustrialChemistry from King Fahd University of Petroleum andMinerals (KFUPM), Dhahran, Saudi Arabia, and his secondin Petroleum Engineering from Tulsa University, Tulsa, OK.

Rafael M. Pino Rojas joined SaudiAramco in June 2013 as a DrillingEngineer working in the DrillingOperations Support Unit of theDrilling Technical Department. He hasover 15 years of experience in technicaland operational procedures, including

coordination and supervision of onshore operations inVenezuela and offshore operations in Saudi Arabia. Rafaelwas trained as a Drilling and Completion Fluids Engineerand has advanced knowledge in the design and fieldapplications of oil-based drilling fluid systems (invertemulsion, 100% oil) and water-based systems (conventional,high performance and drill-in), as well as the elaboration ofdrilling fluids techno-economic proposals under differentcontract schemes.

Prior to joining the company, he worked for BakerHughes for 13 years.

Rafael received his B.S. degree in Chemical Engineeringfrom the Universidad Central de Venezuela, Caracas,Venezuela.

Ahmed E. Gadalla joined SaudiAramco in September 2014 as aDrilling Engineer working in theDrilling Operations Support Unit ofthe Drilling Technical Department. Hehas over 18 years of experience intechnical and operational procedures,

including coordination and supervision of onshore andoffshore operations in several countries. Ahmed was trainedas a Drilling and Completion Fluids Engineer and hasadvanced knowledge in the design and field applications ofoil-based drilling systems (invert emulsions, 100% oil) andwater-based systems (conventional, high performance anddrill-in fluids).

He received his B.S. degree in Geology from MenoufiaUniversity, Al Minufya, Egypt.

Tulio D. Olivares is a Drilling Engineerworking in Saudi Aramco’s DrillingOperations Support Unit of theDrilling Technical Department. He has15 years of experience in technical andoperational procedures, and hascoordinated and supervised onshore/

offshore operations in Venezuela and Saudi Arabia fordifferent companies, including Halliburton, Chevron andSaudi Aramco. Tulio was trained as a Drilling andCompletion Fluids Engineer and has advanced knowledgein the design and field applications of oil-based drillingfluid systems (invert emulsion, 100% oil) and water-basedsystems (conventional, high performance and drill-in).

He received his B.S. degree in Chemical Engineeringfrom the Universidad Rafael Urdaneta, Maracaibo,Venezuela.


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Remediation of Severely Damaged Wells Using Mesophase