KickRisk – a Well Specific Approach to the Quantification of Well Control Risks

IADC Well Control Asia Pacific 2009 Conference & Exhibition, 18-19 November, Bangkok, Thailand, 2009

Øystein Arild, IRISEric Ford, IRISThomas Nilsen, StatoilAntonino Merlo, Eni

Presentation Outline

1. Introduction1. Introduction

2. Conceptual Framework2. Conceptual Framework

3. The KickRisk Kick Model3. The KickRisk Kick Model

5. Summary & Conclusions5. Summary & Conclusions

4. Case study4. Case study

KickRisk - introductionWhat is it?- A software tool and methodology for well control risk management and decision support, with particular emphasis on pressure control

What can it specifically be applied for?- quantification of kick (and blowout probabilities)

- identification of critical factors & risk reducing measures

- comparison of different well design alternatives from a well control risk perspective

Kick module Loss of well control module

KickRisk – overview

The Kick module: facilitates analysis related to kicks

The Loss of Well Control module: analyses the kick scenarios generated in the kick module in terms of kick volume, shut-in possibilities etc and quantifies the blowout probability

Conceptual framework• The traditional approach has been to use

historical data to forecast and quantify risks for future operations

KickRisktakes the view that every well is uniquerequires modeling of physical process in the well integrates relevant uncertainties andphysical models in a Monte Carlo framework

The predictive Bayesian approach:

The KickRisk Kick Model

A porous and permeable formation is exposedThe bottomhole pressure is less than the pore pressure

Kick definition :

The pore pressure (PP), fracturing pressure (FP) and the BHP are all uncertain

The KickRisk Workflow

1

State objectivesof study

2

Input parametersassessment

3

Analysis and evaluation of

results

4

Implementation ofrisk reducing

measures

5

Communicationof results

Case Study• Assignment: an offshore well is to be drilled in

a hitherto unexplored area• Assumptions: poor seismic data and few nearby

wells, the pore and fracturing pressure uncertainty is relatively high

The OperatorIs the operation safe enough ?What are the areas of improvement ?

What is the optimal mudweight

The particular decisions:

Case Study – objectives and input parameters

state objectives of study

assess all the input parameters

Input parameters: Input parameters:

Step 2:

Step 1:

Case Study – input parameters

assess all the input parameters (events)

Input parameters: Input parameters:

Step 2:

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:

The overall kick and fracturing probabilities, covering all the suboperations

P(kick)

P(fracturing)

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:

What can be done to reduce both probability of kick & fracturing ?

The planning team

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:Identification of critical factors

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:Pick the largest kick & fracturing drivers

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:

Mitigate these factorsThe planning team

Risk reducing measures:

Risk reducing measure:

Increased awareness and stricter procedures

The use of shale swelling inhibitors

Case Study – analysis & evaluation

analyze & evaluate the calculation of resultsStep 3:

The planning team

Probability reduction: 60% to 10%

Probability reduction: 60% to 20%

Case Study – implementation

Implement the effective risk reducing measures

Mudweight 1.82 s.g

Rerun the KickRisk tool

New Input

OLD

7,26 %9,72 %P(Fracturing)

P(Kick) ::

Step 4:

NEW

6,44 %3,92 %

Case Study – establish an optimal mudweight

• Assume no further risk reducing measures will be implemented in this case

• Planned mudweight is 1.82 s.gAnalysis and

evaluation of results:Mudweight sensitivity plot

Step 4:

Case Study – communication

Communicate the results with different groupsStep 5:

Summary & Conclusions

• KickRisk is a tool for quantifying risks related to kick and fracturing

• It is based on a well-specific approach and detailed modeling of BHP variations

• It provides decision support related to risk level, risk reducing measures and well design

• A case example was provided to illustrate the practical use of the KickRisk tool

Thanks for your attention!

Any questions?