沙三段储层展布与剩余储量差异化表征

Distribution Pattern and Differential Characterization of Reservoirs in the Sha-3 Formation and Their Remaining Reserves

摘要: 针对断块低渗透油藏高含水期砂体精细刻画难度大、剩余油富集规律不清的技术瓶颈，采用动静态结合的研究方法，以沙河街组三段(沙三段)为研究对象，开展多尺度储层非均质性与剩余储量差异化表征研究。通过引入测井相分析、地震属性优选及相控地质统计学建模等定量化表征技术，结合生产动态曲线分段拟合、含水上升率判别与井间连通性分析，构建了“静态构型–动态响应–剩余储量”一体化预测流程。结合开采十年以上老井的动态递减特征，优化调整注采井网，形成注水驱替流场重构技术，配套实施下部储层限流改造、堵水提液等综合开发措施。研究结果表明，实现了沙三段砂体展布的定量化刻画，精准识别出断层边缘与低渗透夹层控制的绕流剩余油富集区。经现场试验井组治理后，平均单井日产油由1.18 t升至4.98 t，综合含水由96.4%降至82.7%，阶段累计增油超过4500 t，老井自然递减率由1.3%降至0.3%。有效实现了断块高含水油藏的控水增油与持续稳产。

Abstract: To address the technical bottlenecks associated with the difficulty of fine characterization of sandstone bodies in high-water-cut periods of fault-block low-permeability reservoirs, where the patterns governing residual oil enrichment remain unclear, this study employs a combined static and dynamic research approach. Using the Shahejie Formation Member 3 (Sha-3 Member) as the study object, this work conducts a multi-scale investigation into the heterogeneity of the reservoir and the differential characterization of residual reserves. By integrating quantitative characterization techniques such as well logging facies analysis, seismic attribute optimization, and phase-controlled geostatistical modeling, along with segmental fitting of production dynamics curves, discrimination of water-cut rising rates, and inter-well connectivity analysis, this study establishes an integrated prediction workflow encompassing “static configuration-dynamic response-residual reserves”. By leveraging the dynamic decline characteristics observed in wells with over a decade of production history, this study optimizes and adjusts the injection-production well network to develop a water injection displacement flow field reconstruction technology, complemented by comprehensive development measures such as restricted-flow modification of lower reservoir zones and water blocking for liquid recovery. The results demonstrate that quantitative characterization of the sandbody distribution within the Sha-3 Member has been achieved, enabling precise identification of residual oil enrichment zones controlled by fault edges and low-permeability interbeds. Following treatment of the field test well group, the average daily oil production per well increased from 1.18 t to 4.98 t, the overall water cut decreased from 96.4% to 82.7%, the cumulative oil production increase over the stage exceeded 4500 t, and the natural decline rate of the old well decreased from 1.3% to 0.3%. This approach effectively achieves water control and oil recovery enhancement, as well as sustained stable production in fault-block high-water-cut reservoirs.