TERMS OF REFRENCE
WELLBORE STABILITY STUDY
GUDDU EL AREA, OGDCL
OGDCL is planning to have a Wellbore Stability Study, from potential bidders having experience
of providing similar type of services for some of its future wells planned to be drilled in Guddu EL
where it is intended to drill some slant or horizontal wells (having + 615M TVD & inclination
around 70 to 80 degree ). The purpose of the study is to develop Mechanical Earth Model (MEM)
and conduct wellbore stability study in Siwaliks, Drazinda and Pirkoh Limestone.
The model should cover the overburden from surface to the reservoir (Pirkoh Limestone) and
should particularly focus on investigating the risk for borehole instabilities while building angle in
the Siwaliks & Drazinda shales which are dominantly loose formations. The study will provide
practical recommendations for eliminating wellbore instability associated problems, optimum
length for productivity risk prediction for future slant / horizontal wells having inclination around 70
to 80 degree which may be drilled with enhanced Dog Leg Severity (DLS 4.0 or more than 4.0
deg/30M). Maximum and minimum stress regimes etc are also needed to be identified to select
the safest well trajectory profile of proposed well / wells at any specific target location. Two offset
wells will be selected and included in the study, anyhow; if warranted the number of wells can be
increased on merit.
Offset wells data will be provided to construct Mechanical Earth Model in order to constrain the
state of stresses, pore pressure, and mechanical properties over the area for Siwaliks, Drazinda
and Pirkoh Limestone. The operator can provide:
• End of Well Reports (EOWR) that include, mud weights, rate of penetration, drilling
problems and other experiences of the wells for the study purpose.
• Conventional Open Hole Logs ( Reti-1A, Maru-1)
o FMI against Reservoir section, Drazinda and partly (lower part) in Siwaliks
(Conducted at Reti-1A only)
o DSI against Reservoir section, Drazinda and partly (lower part) in Siwaliks
(Conducted at Maru-1 only)
o CMR (Reti-1A and Maru-1)
• Flush Cuttings
• Conventional Core & Core Data of Reti-1 A and Maru-1 (Pirkoh Limestone only)
• DST Data of Reit-1A and Maru-1
• Time Map at reservoir level i.e. Pirkoh Limestone (if required)
In order to determine in-situ stresses, pore pressure, and to develop a Mechanical Earth Model
(MEM) includes rock properties such as unconfined compressive strength, a suite of existing data
from the offset wells be utilized for the model. It should help in the identification of mechanisms
(mechanical & chemical) responsible for the observed well bore instabilities (through generation
of mechanical earth model, micromechanical and shale / sand stability studies). MEM model
should also attempt to use vertical stress data from density logs and pore pressure information to
constrain the full stress tensor as a function of depth.
The operator can provide drilling / well reports that include, mud weights, rate of penetration,
drilling problems and other experiences of the wells for the study purpose. The model should be
used to predict future well performances in the study area, being consistent with previous drilling
experiences. Using this calibration, a robust geo-mechanical model should be prepared which
could serve as a base for assessing borehole stability for the horizontal and the overlying build
section of well/wells, being planned in near future.
A quantitative risk assessment should also be carried out to quantify the effect of uncertainties
associated with the model on the predicted mud weights and to define how different parameters
in the Mechanical Earth Model (e.g. Pore pressure, rock strength, mud activity etc) affect the
likelihood of success. Based upon these uncertainties model need to recommend a data
acquisition program that will help to reduce the uncertainties of the Mechanical Earth Model and
improve the accuracy of future predictions. Study should also optimize drilling performance and
well bore stability.
2. TECHNICAL REQUIREMENTS
Part A: Construction of Mechanical Earth Models
Two offset wells will drilled in the area selected and the bidder / contractor will construct
the Mechanical Earth Model (MEM) for Guddu EL area which will be helpful in predicting
wellbore stability (up to Pirkoh Limestone reservoir) and well trajectories for future slant /
Generate Mechanical Earth Model (MEM) using data from selected wells should
1. Rock elastic properties, Young’s modulus, Poisson’s ratio, shear modulus and bulk
2. Rock strength properties, Unconfined Compressive Strength (UCS) friction angle and
3. Overburden stress
4. Pore pressure.
5. Fracture Gradient Profile.
6. Maximum horizontal stress and minimum horizontal stress magnitudes and
Scope of work
1. Collection, review and validation of all relevant data
2. Reservoir Property Review
3. 1D Mechanical Earth Model for Selected Wells.
• Determine in-situ stress magnitude including overburden stress, maximum horizontal
stress and minimum horizontal stress.
• Estimate rock elastic properties including Young’s modulus, Poisson’s ratio, shear
modulus and build modulus.
• Determine formation pressure profile for both overburden and reservoir.
• Determination of Fracture gradient Profile.
• Validate the MEMs by comparing predicted wellbore instability against image (FMI) if
available, caliper logs and drilling experience and observations up to Pirkoh
Part B: Wellbore Stability Analysis
1. Identify potential drilling hazards
2. Provide optimized drilling practices
3. Predicted MEM based on offset well MEM
4. Predicted stable and safe mud weight windows for each formations
5. Predicted wellbore instability
6. Well trajectory sensitivity analysis considering open hole logging, running in casing &
Scope of Work
1. Collection, review and validation of all relevant data
2. Offset wells drilling review
3. Predict MEM of planned horizontal well
4. Wellbore Stability Analysis, including:
Well bore stability analysis based on the validated MEMs to determine the stable
mud weight, mud weight window and recommended mud weight program and to
identify potential drilling hazards.
• Well trajectory sensitivity analysis on wellbore stability considering open hole
logging, running-in casing & completion.
3. FINANCIAL REQUIREMENTS
The bidder will have to provide detailed cost for the following items:
No. Detail Cost (US$)
1 Lump Sum charges for Generation of Mechanical Earth Model and
Well bore Stability Analysis and well bore stability predictions for Two
(02) well trajectory & submission of final report(s) as per Technical
requirements Part A & B of the bid document.
2 Shale Instability Sensitivity Analysis (if any)
3 Rock Mechanics Laboratory Testing (if any)
4 Future up-gradation of predicted MEM.
5 Additional Offset well Analysis (per well, if any)
6 Additional wellbore stability Analysis (per well, if any)
7 Any additional cost e.g. supplies, communication
1. Bidders should conform to whole technical requirements and work scope.
2. Bidders should have conducted similar studies in Pakistan, study lists should be
3. Best qualified with optimized solutions for full well bore stability will be selected as
Qualified in the range of acceptance of costs among technically qualified bidders.
4. Prospectivity Review
The results of the study should be used to define well trajectory in such a way that the company
is enable to plan and drill the slant well / wells to Pirkoh Limestone level with reasonable
enhancement in reservoir thickness.
5. DATA COLLECTION
The prepared data list will be provided to the Consultant. All the well data available in Guddu EL
and surrounding area (if required) will be collected and incorporated in the list by OGDCL
professionals. The consultant will conduct an initial review/scrutiny of the data to identify any
additional data requirement. The dataset required to achieve the stated objectives might include
o Flush cutting / Core pieces collected from geologic sections.
o Open Hole Wire Line Logs.
o Mud logs
o EOWR (End of Well Report) etc
o Any other additional (available) data as per requirement of the qualified bidder
The final data list will incorporate all data accumulated till the date of award of the contract.
After data collection and compilation, the study will comprise a programme Well Bore Stability.
Well bore stability studies carried out for Guddu Exploration license in the Middle Indus Basin,
Pakistan is proposed to be completed within three (03) weeks from the commencement of the
study. Anyhow keeping in view the scope of work contractor may also propose study duration
acceptable / negotiable to the operator.
PRESENTATION & REPORTS
The proposed Study of the Guddu Exploration license in the Middle Indus Basin, Pakistan
involves the data of approximately two (02) wells. Report should include, in detail, all aspects of
the study. The consulting first will submit a preliminary report for OGDCL review, allowing
sufficient time for OGDCL to complete the review. The final report should incorporate the
changes recommended by OGDCL and agreed by the consultants.
The Consultant may be required to present the key findings of the study to OGDCL Management
and Joint Venture partners at OGDCL head office, Islamabad.
The consultants will supply one proof copy and five final copies of the report. A report may be
named as “Well Bore Stability study of Guddu Exploration License, Middle Indus Basin, Pakistan”,
will also be provided to OGDCL on Compact Disk.
7. GENERAL TERMS
• The Consultancy services will be engaged for completion of the task as required in the
scope of work.
• The contracted firm will provide the required services as per terms of reference/scope of
work etc for this study.
• Transportation of samples and supporting study material will be responsibility of the
• Companies with national/international experience and proven excellent reputation with
technical expertise in this field will be preferred.
• The bidder should be able to perform the work as per international oil industry standards.
The bidder should also indicate the hardware and software to be used for this proposed
• The bidder must be able to complete the proposed study within the specified period of
time agreed upon (study program should be shown in Gantt chart for time).
• Bidder may submit an alternate appropriate study schedule acceptable to operator.
• The project will commence within one week after the signing of the contract.
• The consultant should propose a program (duration in the technical proposal) for the
involvement of professionals from Exploration Department of OGDCL in the subject study
to QC, supervise and assist in study before completion of the preliminary report.
Consultant should also propose the stage when OGDCL professional’s participation can
be of maximum use.
• Expense for the OGDCL’s professional participation in the study will be the responsibility
• An organizational structure of the Proposed Study Group along with CVs of professionals
and detailed methodology indicating work details and work flow schedule is required from
the bidders with bench marks in the technical portion of the bid.
• The personnel who will conduct this study should be dedicated fully to this study.
• Consultant will submit their invoices; OGDCL will make 15% deduction of taxes as
Pakistan corporate tax as per Government of Pakistan rule or any other amount
announced by Government of Pakistan from time to time in this regard. OGDCL shall
make all reasonable efforts to make payment as early as possible against verified
invoices. However no claim for interest/surcharge etc for payment beyond 30 days would
• A penalty of 2.5% per month (Penalty will be charged on per day basis) of the total cost
will be imposed on the consultant if the consultant fails to provide the report within the
committed time period.
• Upon completion of the study, the Consultant will send one copy of draft report and five
(05) copies of the final report along with one digital copy on DVD /CD to OGDCL.
• All data required for the study will be available to the consultant free of charge; such
material will remain the property of OGDCL. The consultant will treat all the data and
information supplied by OGDCL and those acquired by him during the implementation of
the study with utmost confidentiality.
• All kinds of taxes either local & foreign will be paid by the consulting firm only.
• OGDCL reserves the right to discontinue, increase or reduce any study/ task/ service
related to above scope of work at any stage during the study period.
8. EVALUATION CRITERIA
All bidders are requested to submit their bid considering the evaluation criteria. The technical
evaluation will be based on the following criteria.
Total credit points 100
a) Proven Experience of the firm /consultant in proposed study/Evaluation in complex
geological provinces of the world.
Total credit points 15
Year of Established less Credit Established since Credit pts. 8
establishment than ten years pts. 5 ten years or more
No. of Less than 15 Credit More than 15 Credit pts. 7
professionals on Professionals in pts. 5 professionals in
company’s pay related fields related fields.
b) Experience in similar geological settings Total credit points 20
No. studies / Completed ten Credit One credit point Maximum
reports completed studies pts.15 for each study Credit pts. 20
c) Technical work plan and manning schedule. Total credit points 25
Organizational structure of the Study Group and methodology Project completion
indicating work details and work flow schedule. Maximum within stipulated 03
credit pts. 15 weeks. Maximum credit
d) Personnel (Qualification) Total credit points 10*
B.Sc. Credit pts. 5 M. Sc. Credit pts. 10
e) (Experience) Total credit points 15*
Less than 10 Credit pts. More than 10 Credit pts. More than 15 Credit pts.
years in 5 years in 10 years in 15
related fields related fields related fields
f) Software applications Total credit points 15
Workstation based experience and use of One credit point for each attachment to
specialized softwares. OGDCL counterparts. Maximum Credit
Maximum Credit pts.10 pts 5
The financial proposal of bidders obtaining less than 70% points in total and less than 60%
points of each category in the technical evaluation will not be opened.
9. EVALUATION OF PROPOSALS
Technical proposal shall be reviewed first to determine its technical responsiveness and
conformity with the requirement of TOR. After completion of Technical Evaluation, the
Financial Proposal of only the technically responsive / qualified bidder(s) shall be opened
and evaluated. The bids requiring substantial modifications to make it responsive shall be
rejected out rightly.
9.1 Technical Evaluation
Technical proposal of the bidder shall be reviewed first to determine / check its technical
responsiveness and conformity with the requirement of TOR. In all 100 marks have been
assigned for Technical conformity of the bid out of which the qualifying marks are 70%.
The technical evaluation shall be carried out according to the above technical evaluation
schedule. The technical portion of the bid shall carry over-all weightage of 70% in
Technical cum financial evaluation for award of contract.
Technical marks weightage of qualifying bidders shall be calculated as under;
Total technical marks obtained X 70 whole divided by 100 = Total technical weightage.
Suppose a bidder obtains 90 marks out of 100 marks in the technical evaluation, it’s total
technical weightage shall be 90 X 70 / 100 = 63%. Where as another bidder obtains
qualifying marks 70, then its total technical weightage shall be calculated as 70 X
70 / 100 = 49%.
9.2 Financial Evaluation
The Financial Proposal of only the technically responsive bidder(s) shall be considered
and evaluated. The cost will be evaluated upon entire project completion lump sum cost
basis including third party cost; materials cost all type of taxes etc. The financial portion
shall carry over-all 30% weightage in final technical cum financial evaluation for award of
contract. The bidder with lowest financial offer shall be given full 30% marks for award.
The financial marks / weightage for other bidders shall be calculated as under.
Total financial value of lowest bidder X 30 divided by total financial value of other bidder.
Suppose the financial bid of second lowest bidder is US $ 60,000-00 then his financial
weightage will be 50,000 X 30 / 60,000 = 25
The bidder attaining highest marks in technical cum financial evaluation will be awarded
The bids requiring substantial modifications to make it responsive shall be rejected outright.
FINANCAIL BID FORMAT
The rate per day for each category of staff.
Rates per day for services to be performed during the execution of the study (detail must
Total lump sum project cost inclusive of the third party charges if any.
Payment will be subject to deduction of withholding tax at source as per rules of
Government of Pakistan.
OGDCL shall not be held liable for any expenses incurred with the preparation or
submittal of the proposals or any subsequent discussion and / or negotiations.
The lump sum quoted cost should be inclusive of all charges for complete study i.e.
laboratory services, deliverable etc.