Improving Oil Recovery in Complex Heterogeneous Reservoirs of Highly Mature Oil Fields through Innovative Measurement and Strategies: A Case Study from South China Sea

摘要

Located in South China Sea, B oil field has entered into mature development phase. A horizontal drilling campaign was initiated to develop the remaining oil reserve within the heterogeneous reservoirs with multiple laminated layers. To address the challenges and uncertainties of drilling horizontal wells in these complex reservoirs, an innovative approach and strategy were introduced and employed for optimal well placement in a specific heterogeneous reservoir. This approach includes the advance distance-to-boundary mapping service and the high-definition multiboundary mapping service with the ability to map multiple key boundaries within reservoirs. Best practices have been developed for using this innovative approach in strategic planning and real-time well placement of horizontal wells in the field for the efficient draining of the reservoir. These include the description of the detailed reservoir profile, the sweet zone identification while drilling, and the lateral placement close to the sweet zone top to minimize the attic oil and extend the well life. The outcomes in two successful wells were: · Clear identification of multiple boundaries of the reservoir geobodies and their interfaces including the current fluid contact level. · Minimization of attic oil and achieving optimum lateral placement to drain the reservoir. · Exceeding the economic prediction of heterogeneous reservoirs The successful implementation of the innovative well placement strategy in complex and heterogeneous fields will lead to extended production, optimal well economics, and increased oil recovery. The approach provides an example of using integrated technology solutions to overcome the challenges in complex reservoirs with multiple laminated layers.