Challenge
A major oil and gas company was challenged with further development of an existing deepwater field. While the field had a good reserve potential, it was highly compartmentalized with multiple reservoirs at a variety of pressures requiring expensive wells that were difficult to drill and to complete. The drilling service companies that supported operations and the drill ship had been highly inefficient resulting in previous wells that were significantly over budget with completions that were often compromised. The existing field development plan had wells that would be highly deviated and passed through several different pressure regimes and/or hard lithologies at high angles in order to reach multiple targeted reservoirs. It was thought that a new dynamically positioned drilled ship would be required to overcome the difficulties previously experienced.
Solution
Decision Strategies met with client’s expanded team which consisted of members from all aspects of field development: subsurface, drilling, completions, operations, human resources, procurement, planning and economics. The expanded team’s role was to bring critical issues to light and to find the best path forward.
DSI’s decision management process allowed the conflicting objectives to surface for analysis and resolution. The new team quickly became aligned on a common goal, and DSI assisted the client team in generating a comprehensive and creative set of strategic options to meet the stated objective. Some of the options included: moored rig or dynamically position 3rd or 5th generation rig, subsea trees with tie backs versus a tension leg platform with dry trees, straight wells with simple completions versus deviated wells and multiple completions.
DSI conducted interviews with subject matter experts to assess major uncertainties such as capital costs, drilling time, failure rates, reserves and production response. Using this information, DSI and the client team developed a probabilistic model to analyze each of strategic options. Additionally, the strategies were required to honor existing contractual production sharing agreement while still meeting the stated objective. DSI’s value analysis determined that the best strategic option included:
- A 3rd generation dynamically positioned rig should be used.
- Multiple straight holes with simple completions were preferable to highly deviated holes with multiple completions.
- Smaller reservoirs could be profitable with the reduced costs.
Result
Using Decision Strategies’ process to add clarity to the strategic options, the project team developed and implemented an improved strategy that improved the value of the planned development of this complex and difficult field by $350 Million.