Feasibility of Optimizing and Reserves from a Mature and Geological Complex Multiple Turbidite Offshore California Reservoir Through the Drilling and Completion of a Trilateral Horizontal Well.

The main objective of this project is to devise an effective re- development strategy to combat producibility problems related to the Repetto turbidite sequences of the Carpinteria Field. The lack of adequate reservoir characterization, high-water cut production, and scaling problems have in the past contributed to the field`s low productivity. To improve productivity and enhance recoverable reserves, the following specific goals were proposed: (1) Develop an integrated database of all existing data from work done by the former ownership group. (2) Expand reservoir drainage and reduce sand problems through horizontal well drilling and completion. (3) Operate and validate reservoir`s conceptual model by incorporating new data from the proposed trilateral well. (4) Transfer methodologies employed in geologic modeling and drilling multilateral wells to other operators with similar reservoirs. Pacific Operators Offshore, Inc. with the cooperation of its team members; the University of Southern California; Schlumberger; Baker Oil Tools; Halliburton Energy Services and Coombs and Associates undertook a comprehensive study to reexamine the reservoir conditions leading to the cent field conditions and to devise methodologies to mitigate the producibility problems. A computer based data retrieval system was developed to convert hard copy documents containing production, well completion and well log data into easily accessible on-line format. To ascertain the geological framework of the reservoir, a thorough geological modeling and subsurface mapping of the Carpinteria field was developed. The model is now used to examine the continuity of the sands, characteristics of the sub-zones, nature of water influx and transition intervals in individual major sands. The geological model was then supplemented with a reservoir engineering study of spatial distribution of voidage in individual layers using the production statistics and pressure surveys. Efforts are continuing in selection of optimal location for drilling and completion of probing wells to obtain new data about reservoir pressure, in-situ saturation and merits of drilling a series of horizontal wells. The probing re-drills and horizontal wells are scheduled for Budget period 11. Information generated on the characteristics of the geology and reservoir setting have been presented at various SPE Meetings and Tech Transfer workshops of PTTC. Oil and gas professionals from State and Federal agencies have visited POOI offices and have received briefings on the Carpinteria re-development progress