A Methodology for Precise Flow Contribution and Allocation in Multi-lateral Wells

Abstract

Production allocation and optimization in multi-lateral wells is an industry-wide challenge that impacts sweep efficiency, water survival rate, and economic metrics among other key parameters. The challenge is more prevalent in heterogeneous reservoirs where both lateral and vertical heterogeneity impact production performance. Robust understanding of the complex interaction between reservoir geology and wellbore flow dynamics is pivotal to making informed reservoir management decisions to optimize offtake from each lateral, refine lateral count, and reservoir exposure. This paper presents an integrated workflow for evaluating flow contribution and production allocation in multi-lateral wells to optimize production performance and maximize economic value. The workflow combines flow control valves, permanent downhole pressure monitoring systems, individual and commingled rate testing, with mathematical wellbore modeling to accurately evaluate flow contribution. These optimizations are key to ensuring uniform pressure differentials among different laterals to prevent premature water breakthrough and uneven sweep patterns. This approach enables accurate production allocation without the need for frequent production logging. Moreover, the methodology enables a continuous feedback loop to evaluate the accuracy of implemented optimizations and provide guidance on further enhancements. The integrated workflow was applied in a successful field trial application, where a production log was conducted to verify the estimated production parameters. The test yielded a 95% match in fractional flow and productivity index estimation. Thus, the estimates were considered reliable and utilized for additional analysis. When implemented at scale, the workflow has the potential to optimize the wells performance and prolong production lifecycle through making timely, effective, and well-informed decisions. In addition, it will reduce operating expense and eliminate high risk routine wireline and coiled tubing logging operations.