1. Probabilistic Estimates of Deepwater Offshore Field Abandonment Cost
25-May-16

4. How to deal with uncertainty? – Probability!!!
Why probabilistic?
What is known?
What is not known?
What can change (uncertainty)?
How can probabilistic estimates improve?

5. 2014 Estimate 4 pipelines, 3 EHU, 2 drill centers, jumpers
1 subsea well TA, leave wellhead
5 subsea wells to PA leaving wellhead
1 subsea well to PA removing wellhead

6. 2014 Estimate -> Update to 2016
2014 Probabilistic Estimate
4 pipelines, 3 EHU, 2 drill centers, jumpers
1 subsea well TA, leave wellhead
5 subsea wells to PA leaving wellhead
1 subsea well to PA removing wellhead
P10
P50
P90
Subsea Field - Duration Variance
$ ,388,667
$ ,054,011
$ ,046,677
Well PA - Remove Wellhead - Duration Varied
$ 21,108,555
$ 24,355,233
$ 29,186,019
5 Well PA - Leave Wellhead - Duration Varied
$ 97,815,183
$ 113,850,544
$ 137,635,157
Well TA to PA - Duration Varied
$ 14,143,240
$ 17,749,254
$ 22,954,455
Total
$ 137,455,645
$ 161,009,042
$ 195,822,308

7. Probabilistic – Cumulative Distribution Function
Well PA - Remove Wellhead - Duration Varied
$ 21,108,555
$ 24,355,233
$ 29,186,019

8. Start to build the model
What is known?
Subsea field:
4 pipelines, 3 EHU, 2 drill centers, jumpers
1 subsea well TA, leave wellhead
5 subsea wells to PA leaving wellhead
1 subsea well to PA removing wellhead
Define actions
Identify steps and durations for each step
Refine durations with minimum, most likely, maximum
Define requirements & limitations of actions
Run rates, trip times, time to surface, tool up, tool down, flush time, cut, etc…
Define limitations due to company or vendor requirements

9. What is not known? Identify unknowns – that have impact
Problems with wells – additional steps
Potential – re-squeeze, additional plug, additional trip to recover hardware
Define chance and impact – add to model
Problems with operations – extended duration
Extend flushing, additional WOC time
Redefine max duration if can
Expected issues – required contingencies
Back up, stand by eqt
Add duration and spread

10. What can change? Uncertainty
Oil price
Resource rates
Resource availability
Weather
Additional costs
Hope
Use distribution of rates
Define window of operations – revise above
Apply weather percentage
Apply % or cont.

11. Impact of modifying the model to vary rates
Estimate with fixed 2014 Rates - Duration Varied
Estimate with Rates & Duration Varied
Components
P50
Subsea Field
$ ,054,011
$ ,455,757
Well PA - Remove Wellhead
$ ,355,233
$ ,639,829
5 Well PA - Leave Wellhead
$ ,850,544
$ ,216,826
Well TA to PA
$ ,749,254
$ ,528,814
TOTAL
$ ,009,042
$ ,841,226

12. Impact of modifying the model to vary rates

13. Impact of modifying the model to vary rates
Range of rates

14. Impact of modifying the model to vary rates
Range of rates

15. Impact of modifying the model to vary rates
Range of rates

16. How can probabilistic estimates improve?
How to make a better crystal ball…
Job data:
Field specific data – percentage problem wells, percentage squeeze success, durations of tasks (min/most likely/max)
WOC durations - effectiveness
Range of rates vs date of operation
Impact of previous problems – cost & duration
Better information = more accurate estimate
More data – larger pool

17. Can probabilistic estimates determine a methodology?
Will use of resins be more cost effective vs risk of a repeat squeeze?
Will use of Riserless intervention be more cost effective?
Probabilistic analysis can better define the costs for comparison

18. Probabilistic analysis for the future…
Questions?