缝洞体系连通性分析——塔北深埋碳酸盐岩研究的一个实例

Analysis of fracture- cavern system connectivity: a case study of carbonate rocks in Tabei area

缝洞型碳酸盐岩是塔北地区哈拉哈塘油田主要储集层,油藏的储渗空间主要为规模不同的洞穴、溶蚀孔隙以及各级裂缝。缝洞连通性是油田勘探开发实践中高效井优选的重要依据,油田勘探开发实践证实,油藏呈现为由洞穴、孔洞和裂缝组成的相互连通的大型缝洞集合体的特征,且紧邻缝洞集合体的油藏开发情况差异非常大,油藏压力、日产量与累积产油量等都不同,给油田的开发带来困难。研究中针对缝洞型储层的强非均质性,提出裂缝强度量化描述、裂缝方向量化描述与动态资料相结合的研究思路与技术方法,通过三维油藏建模技术研究缝洞的连通性以及确定大型缝洞集合体的边界,结合实际生产情况,指导油藏高效开发井组部署。

The fracture -cavern carbonate rocks are the main reservoirs for Halahatang Oilfield in Tabei area.The res-ervoir and flow space mainly consist of various scale of caves,dissolution pores and fractures.The fracture -cavern connec-tivity plays an important role in screening high efficient wells in the exploration and development practice of oilfield.The exploration and development practice indicated that the oil pool presents the characteristics of fracture -cavern type aggre-gation,which is communicated by caves,vuggy and fracture.The difference of reservoir development situation,such as res-ervoir pressure,daily oil production and cumulative oil production,is too large between the immediate vicinity aggregations, which brings a lot of difficulties to the oilfield development.In view of the strong heterogeneity of the fractured vuggy reser-voir,the study technological method was put forward,in which the quantitative description of fracture density and fracture direction was combined with dynamic production data.By 3D reservoir modeling,the connectivity of fracture -vuggy and the border of fracture -cavern type aggregation were determined,guiding the deployment of high efficiency well group based on the actual production situation.