SZ36-1油田聚驱后提高采收率方法探析  

Analysis of Methods for Enhancing Oil Recovery after Polymer Flooding in SZ36-1 Oilfield

作　　者：陈斌 Chen Bin(Energy Economics Research Institute of CNOOC,Beijing 100013)

机构地区：[1]中国海油集团能源经济研究院,北京100013

出　　处：《中外能源》2022年第5期55-61,共7页Sino-Global Energy

摘　　要：SZ36-1存在油水关系复杂、非均质现象严重、油井作业困难等因素制约研究区采收率。为进一步提高SZ36-1油田动用程度,采用数值模拟分析聚驱后剩余油分布位置,对二元驱、高浓度聚驱及气聚交替影响因素进行研究,并结合数值模拟结果对比三种方法驱油效果,优选适合研究区的提高采收率方法。结果表明:研究区属于稠油油藏,地下原油物性差异较大,剩余油主要分布在断层附近等注聚没有波及到、波及程度较低的部位;三种化学驱影响因素存在差异,其中二元复合驱受表活剂及聚合物浓度影响,高浓度聚驱受聚合物浓度、聚合物用量及注入速度影响,气聚交替注入驱气液比为关键因素;通过全区采收率模拟分析,认为聚驱后气聚交替注入驱替效果最好,但受限于气源,无法实现大规模全区注入,建议对油层顶部剩余油及一些化合驱不可及的区域进行局部注入,最后综合海上油田现场条件及生产情况,认为二元复合驱具有更高的适用性,可大大提高海上油田聚驱后采收率。Complex oil-water relations,serious heterogeneity,and oil well operation difficulties in SZ36-1 restrict the oil recovery of the study area.In order to further improve the producing degree in SZ36-1 Oilfield,numerical simulation is used to analyze the remaining oil distribution after polymer flooding.The influencing factors of binary flooding,high-concentration polymer flooding and gas-polymer alternating flooding are studied,and the flooding results of the three methods are compared combined with the results of numerical simu-lation,and method for enhancing oil recovery suitable for the study area is selected.The results show that the study area belongs to heavy oil reservoirs,and the physical properties of underground crude oil are quite different.The remaining oil mainly distributes near faults and other parts that have not been swept by polymer flooding or have low degree of swept efficiency;there are differences among the influencing factors of three chemical flooding :binary combination flooding is affected by surfactant and polymer concentration,high-concentration polymer flooding is affected by polymer concentration,polymer dosage and injection rate,and gas-polymer alternating flooding is affected by gas-liquid ratio mainly.The simulation result of oil recovery in the whole area indicates that the effect of gas-polymer alternating flooding after polymer flooding is the best,but it can′t be applied at large scale in the whole area restricted by the gas source.It is recommended to inject in the area of remaining oil on the top of the reservoirs and not being swept by chemical flooding.According to on-site conditions and production conditions of offshore oilfields,it suggests that binary combination flooding has higher applicability and can greatly improve the oil recovery of offshore oilfields after polymer flood-ing.

关 键 词：海上油田 剩余油 数值模拟 驱替效果 采收率 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]