基于构型单元“势控论”研究与剩余油开发效果分析

为了研究剩余油的开发效果，综合利用地震、地质、生产动态等资料，将"构型精细解剖"与"势控论"相结合，基于单砂体构型单元进行油水动态运移规律研究，从运移方向和时间角度，预测剩余油运移与聚集规律，构建"运聚再生油藏模式"，提出低势闭合区是剩余油挖潜的重点区域。Y油田主力储层夹层少且薄，砂体连片展布，以堆叠接触为主，关停后1 a左右，零散分布的剩余油向低井控、低势能的构造高部位进行运移聚集；非主力储层夹层发育规模大且厚，砂体发育类型包括堆叠、侧叠和孤立型，零散剩余油在纵向上运移受到夹层遮挡，砂体内运移方向受韵律性影响，横向上砂体之间接触类型决定剩余油聚集规模，关停后3 a以上时间，剩余油逐渐向油藏低势闭合区富集成藏。Z9非主力油藏低势闭合区Y1-6 H井平均日产油超过200 m³，含水率低于5%，已稳产4 a；构造高部位Y1-3 H井平均日产油低于60 m³，含水率约75%，现已关停，远低于低势闭合区生产效果，其他非主力油藏低势闭合区剩余油也取得了较好的挖潜效果。Y油田挖潜资料证明了低势闭合区"动态运聚再生油藏模式"的合理性，可为海上中后期老油田剩余油挖潜提供技术支持。

Potential control theory based on configuration unit and remaining oil development effect

In order to study the development effect of remaining oil,by synthetically utilizing seismic,geological and dynamic production data,combining "fine anatomy of configuration" with "potential control theory", the dynamic migration law of oil and water was studied based on single sand body configuration unit,and the migration and accumulation law of remaining oil was predicted from the migration direction and time. The model of migration and accumulation regeneration reservoir was established,and the low potential closed area was put forward as the key area for tapping remaining oil potential. Taking Y oilfield as an example,the main reservoir has few and thin interbeds,and sand bodies are distributed in succession,mainly in stacked contacts. About one year after shutdown,the scattered remaining oil migrated and accumulated to the high parts of low well control and low potential energy structures. The interbeds developed in non-main reservoirs were large and thick. Sand bodies were dominated by stacking and lateral overlapping isolated type. The vertical migration of scattered remaining oil was blocked by interbeds,and the migration direction of sand body was affected by rhythm. Lateral contact types between sand bodies determined the accumulation scale of remaining oil. After shutdown for about 3 years,the remaining oil gradually enriched and formed reservoirs in low-potential closed zones of reservoirs. The average daily oil production of well Y1-6 H in low potential closed zone of Z9 non-main reservoir is over 200 m³,water cut is less than 5%,and the production has been stable for four years. The average daily oil production of well Y1-3 H in high structural position is less than 60 m³,and water cut is about 75%. Now it has been shut down,its production effect is much lower than that of low potential closed zone. The remaining oil of other non-main reservoirs in low potential closed zone has also achieved good potential tapping effect. Potential tapping data prove the rationality of "dynamic migration and accumulation regeneration reservoir model" in low potential closed zone,which can provide technical support for remaining oil tapping in old offshore oilfields in the middle and later stages.