Wellbore Stability and Formation Damage Study

Well bore Stability and Well bore Stability and Formation Damage StudyFormation Damage Study

Collaborative research project Collaborative research project between School of Petroleum between School of Petroleum

Engineering (SCOPE), University of Engineering (SCOPE), University of New South Wales, Australia and the New South Wales, Australia and the

Institute of Drilling Institute of Drilling Technology(IDT), ONGCTechnology(IDT), ONGC

Proposal for

REASONS FOR STUDYREASONS FOR STUDY•Well Bore instability while drilling through high dip, geo-stressed & chemically active formations is a challenge

•High angle, Horizontal / ERD wells are also prone to well bore instability leading to Stuck Pipe, Mud loss etc

•UBD wells that ONGC is planning in onshore assets also require the study to know safe mud weight window

•Proper fluid selection for avoiding excessive mud weight to control caving for reducing formation damage

Science of Well Bore Stability analysis has progressed considerably in recent times

Well established fact that proper field specific studies on Rock Mechanics, Drilling Fluid – Rock Interaction results in Proper Well Bore Trajectory Planning, Suitable Mud Weight Window to prevent instability and optimal fluid design causing minimum formation impairment

REASONS FOR STUDYREASONS FOR STUDY• IDT does not have requisite expertise to carry out novel well planning mechanism on its own

• Institute was exploring for a work association with a reputed institute in this regard

• School of Petroleum Exploration (SCOPE), University of New South Wales, Australia has done commendable job in the stated fields

• SCOPE also has a MOU with ONGC in Drilling & Petroleum Production

• SCOPE has agreed for a Work Association with IDT to carry out Well Bore Stability and Formation Damage Study for the candidate fields of ONGC

•Caving Prone areas of Ankleshwar Asset

•Horizontal wells of Ahmedabad asset

•Under Balanced Drilling Candidate wells of Ahmedabad and Mehsana Asset – Determine safe mud weight window to hold formation from collapsing during Under Balanced Drilling

FIELDS OF ONGC TO BE TAKEN UP FIELDS OF ONGC TO BE TAKEN UP FOR THE STUDYFOR THE STUDY

TOTAL COST OF THE PROJECT:

$ 421,900 Au

Rs 1,47,66,500/- (@ $ Au = Rs 35/-)

COST BENEFIT ANALYSISCOST BENEFIT ANALYSIS

COST BENEFIT ANALYSISCOST BENEFIT ANALYSIS

S No

Asset / Basin Wells Days Lost

1 Ankleshwar Asset ANGH; GNPL; GNTL; GNTA; GNTZ; KIDG; GNTA

394

2 Ahmedabad asset NJES; WNEY 47

3 Mehsana Asset NKLM; NKNJ 14

4 W. Onshore Basin Rajpardi 280

Total Days Lost = 735 for 3 Years; Av. Rig Days Lost / Year = 245

•Cost of Lost days for W. Onshore wells / year for bore hole instability = 245 days x Rs 3 Lakhs / day (Dep. Rig cost) = Rs 7.35 Crores [ Taking International cost of Land rig, the cost works out = 245 x $ 10,000 per day = $ 24,50,000 US = Rs 11 Crores (Exchange Rate = Rs 45/-)

•Project Cost = Rs 1.47 Crores + Additional (say, Rs 18 Lakhs) = Rs 1.65 Crores

Hence, the Project should be financially viable

COST BENEFIT ANALYSISCOST BENEFIT ANALYSIS

INTANGIBLE BENEFITINTANGIBLE BENEFIT•Acquiring new expertise and Knowledge / Technology transfer

•Acquired skill may be fruitfully applied to other ONGC fields for reducing complications and lost time incidents

•Up gradation of IDT laboratory during study period without paying for additional consultancy charges

•Totally new approach in well planning

SCOPE OF THE PROJECTSCOPE OF THE PROJECT

Task 1 – Data Collection and Data ReviewTask 1 – Data Collection and Data Review

AAnalysis of all the available data from the nalysis of all the available data from the study areastudy area and to and to identify any data gapsidentify any data gaps

ActivityActivity CostsCosts

Data CollectionData Collection $ 23,100 Au$ 23,100 Au

Evaluation of DataEvaluation of Data $ 8,250 Au$ 8,250 Au

ReportsReports $ 3,300 Au$ 3,300 Au

TOTALTOTAL $ 34,650 Au$ 34,650 Au

Task 2 – Characterisation of Petrophysical, Task 2 – Characterisation of Petrophysical, Chemical Chemical && Mechanical Rock Mechanical Rock PropertiesProperties

- - DDetermination of in-situ stresses and etermination of in-situ stresses and wellbore stability analysiswellbore stability analysis-Log interpretation Log interpretation && triaxial test on core triaxial test on core samples to derive porosity, permeability, samples to derive porosity, permeability, Young’s modulus, Poisson’s ratio Young’s modulus, Poisson’s ratio etcetc-Core analysis using binocular microscopy, Core analysis using binocular microscopy, scanning electron microscopy (SEM), X-ray scanning electron microscopy (SEM), X-ray diffraction (XRD) to determine mineral diffraction (XRD) to determine mineral content and distribution, clay types of content and distribution, clay types of reservoir formationsreservoir formations-Determination of capillary pressure and Determination of capillary pressure and pore size distributions by mercury pore size distributions by mercury injection/nitrogen absorptioninjection/nitrogen absorption

SCOPE OF THE PROJECTSCOPE OF THE PROJECT

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 2 – Characterisation of Petrophysical, Task 2 – Characterisation of Petrophysical, Chemical Chemical && Mechanical Rock Mechanical Rock PropertiesProperties

Activity Costs

Log Analysis to Determine Rock Properties $ 37,950 Au

Triaxial Test on Cores for Rock Properties $ 4,950 Au

Core Analysis to Determine Mineral Content & Reservoir Rock Distribution (at IDT)

-

Determination of capillary pressure and pore size distributions (at IDT)

$ 4,950 Au

Reports $ 3,300 Au

TOTAL $ 51,150 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 3 – In-Situ Stresses Task 3 – In-Situ Stresses & & PorePore PressuresPressures

- - PPore pressure prediction from log ore pressure prediction from log / / seismic velocity data seismic velocity data and fromand from relationships relationships ofof rock physics, local rock physics, local ccalibrationsalibrations & & regional trends regional trends- - Stress orientation Stress orientation from from borehole borehole bbreakoutsreakouts / / induced fractures from induced fractures from dipmeterdipmeter, , imageimage, , calipecaliper - r - Vertical stress Vertical stress determination from density logsdetermination from density logs- H- Horizontal stress determination from orizontal stress determination from well logswell logs, , LOT, Extended LOT, minifrac LOT, Extended LOT, minifrac tests etctests etc - - Stress constraining technique applied to Stress constraining technique applied to determine the maximum and minimum determine the maximum and minimum horizontal stress boundshorizontal stress bounds..

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 3 – In-Situ Stresses Task 3 – In-Situ Stresses & & PorePore PressuresPressures

Activity Costs

Prediction of Pore pressure from Log Data (to be carried out at IDT/KDMIPE)

-

Prediction of vertical stress from log data $ 8,250Au

Determination of Stress Orientation $ 9,900 Au

Determination of Minimum Horizontal Stress $ 19,800 Au

Determination of Maximum Horizontal Stress $ 19,800 Au

Reports $ 3,300 Au

TOTAL $ 61,050 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 4 – Wellbore Stability Analysis, Including Chemical / Physical Interaction Between Drilling Fluid and Formations-Characterization of pore pressure and stress changes induced by capillary effect (pressure penetration), chemical potential (osmosis flow) and swelling effects (interaction between drilling fluid and clay minerals)-Determination of shale/claystone membrane efficiency and water activity of formation fluid. - Numerical modelling of wellbore stability by integrating poroelastic theory, capillary effect, chemical potential and swelling effects-Determination of safe mud weight windows

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 4 – Wellbore Stability Analysis, Including Chemical / Physical Interaction Between Drilling Fluid and Formations

Activity Costs

Characterization of Pore Pressure & Stress Changes due to Capillary / Chemical / Swelling Effects

$ 16,000 Au

Determination of Shale/Claystone Membrane Efficiency and Water Activity of Formation Fluid

$ 24,000 Au

Numerical Modeling of Well bore Stability & Determination of Safe Mud Weight Windows

$ 29,700 Au

Reports $ 3,300 Au

TOTAL $ 73,000 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 5 – Formations Damage Prevention, Task 5 – Formations Damage Prevention, Evaluation and RemediationEvaluation and Remediation:: - - Water sensitivity tests to determine Water sensitivity tests to determine critical salt concncritical salt concn.. of drilling/completion of drilling/completion fluid to evaluate permeability impairment fluid to evaluate permeability impairment ofof fluid rock interaction fluid rock interaction- - Quantitative analysis of permeability Quantitative analysis of permeability impairment due to mud filtrate, solid impairment due to mud filtrate, solid particle invasion using dynamic filtration particle invasion using dynamic filtration test. test. - - Pore-level study of the effect of mud Pore-level study of the effect of mud chemistry and fluid-rock interaction on the chemistry and fluid-rock interaction on the microscopic structure of mud-cake and microscopic structure of mud-cake and mud caking process using advanced mud caking process using advanced electronic microscopyelectronic microscopy and other and other specialised facilitiesspecialised facilities

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 5 – Formations Damage Prevention, Task 5 – Formations Damage Prevention, Evaluation and RemediationEvaluation and Remediation

Activity Costs

Determination of Critical Salt Concentration for Drilling Fluid

$ 3,300Au

Evaluation of Permeability Impairment by Dynamic Filtration

$ 3,300 Au

Pore-Level Study of Mud Caking Process $ 3,300 au

Reports $ 3,300 Au

TOTAL $ 13,200 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 6 – Design of drilling and completion Task 6 – Design of drilling and completion

fluids for specific well conditionsfluids for specific well conditions

- - Analysis of Analysis of lithology profiles, mineral contents, lithology profiles, mineral contents,

drilling reports drilling reports including performance analysis including performance analysis

of drilling/completion fluidsof drilling/completion fluids, , experimental experimental

results of fluid-rock interaction and dynamic results of fluid-rock interaction and dynamic

filtrationfiltration

- - Development of a basic fluid program Development of a basic fluid program

based on the previous analysisbased on the previous analysis

- - Evaluation of chemical and functional Evaluation of chemical and functional

properties of the selected mud systemsproperties of the selected mud systems

SCOPE OF THE PROJECTSCOPE OF THE PROJECT

Task 6 – Design of drilling and completion Task 6 – Design of drilling and completion

fluids for specific well conditionsfluids for specific well conditions

Activity Costs

Screening of Drilling/Completion Fluid for Specific Well Conditions

$ 4,950 Au

Reports $ 3,300 Au

TOTAL $ 8,250Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 7 – Well Planning and Wellbore Risk Task 7 – Well Planning and Wellbore Risk

AnalysisAnalysis

- - Determination of collapse and fracture Determination of collapse and fracture

gradients. gradients.

- - Characterisation of natural fracture systems to Characterisation of natural fracture systems to

determine fracture density and orientation.determine fracture density and orientation.

-- HHybrid stochastic simulation to integrate all ybrid stochastic simulation to integrate all

the characterised fracture behaviours to the characterised fracture behaviours to

generate discrete fracture network of the study generate discrete fracture network of the study

areaarea

- - Design optimum wellbore trajectory and casing Design optimum wellbore trajectory and casing

program based on reservoir properties and program based on reservoir properties and

nature fracture system, wellbore stability nature fracture system, wellbore stability

analysis, collapse and fracture gradient analysis, collapse and fracture gradient

together with torque and drag analysis and together with torque and drag analysis and

borehole cleaning efficiency analysis borehole cleaning efficiency analysis

- - Wellbore risk assessmentWellbore risk assessment

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 7 – Well Planning and Wellbore Risk Task 7 – Well Planning and Wellbore Risk

AnalysisAnalysis

Activity Costs

Determination of collapse and fracture gradients $ 11,550 Au

Characterization & Modeling of Natural Fractures $ 37,950 Au

Design optimum well bore trajectory & casing program

$ 19,800 Au

Well bore risk assessment $ 24,750 Au

Reports $ 3,300 Au

TOTAL $ 97,350 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTTask 8 – Finalisation of the Task 8 – Finalisation of the ProjectProjectThis stage will include archiving, report This stage will include archiving, report presentation, and transfer of Software presentation, and transfer of Software

License of “Stress Check” & “Bore Map”.License of “Stress Check” & “Bore Map”. Activity Costs

Transfer Software licensing “Stress Check” & “Bore Map”

$ 75,000 Au

Final Reports $ 8,250 Au

TOTAL $ 83,250 Au

SCOPE OF THE PROJECTSCOPE OF THE PROJECTVISIT OF SCOPE PERSONNEL TO IDTTask 1: 1.1 - 2 Persons x 7 Days = 14 man DaysTask 2: 2.2 - 3 man days; 2.4 - 3 man Days = 6 Man DaysTask 5: 2 Man Days each for Tasks 5.1 to 5.3 = 6 man daysTask 6: 6.1 = 3 Man Days

ONGC TEAM VISIT TO SCOPE, AUSTRALIA

Task 2.1, Tasks 3.2 to 3.5, Entire Task 4, Entire Task 7

SCOPE OF THE PROJECTSCOPE OF THE PROJECTCOMPOSITION OF ONGC TEAM

Project requires multi disciplinary approach in the fields of Drilling Technology, Drilling Fluid Engineering and Log Interpretation Following composition of ONGC team is required:

Drilling Technology : Two Officers from IDTDrilling Fluid Engineering: Two Officers from IDTLog Interpretation : One Officer from Logging, KDMIPE

SCOPE OF THE PROJECTSCOPE OF THE PROJECT

ADDITIONAL COSTS INVOLVED

•To and Fro Air Fare to SCOPE Personnel from Australia to India as per actuals

•Hospitality to SCOPE Personnel in India as per prevailing rules

•To and Fro Air fare to ONGC Team from India to Australia and DA for stay at Australia as per rules

IDTIDT officers in work association officers in work association

shall be shall be traintraineded and mentor and mentoreded

through out the project durationthrough out the project duration

SCOPE OF THE PROJECTSCOPE OF THE PROJECT

APPROVAL OF ECAPPROVAL OF EC

Case put up to EC for approval as the

proposal pertains to BDP No. RS 4 (Enter

into collaboration with University or a

Research Organization : To be exercised by

the institutes) and as per the Notes, the

proposal require approval of EC