鄂尔多斯盆地东部盒8段致密砂岩储层特征——以子洲气田清涧地区为例
Tight Sand Reservoir Features of He 8 Member in Eastern Ordos Basin: A Case Study of Qingjian District in Zizhou Gasfield

摘要： 清涧地区位于鄂尔多斯盆地东部，是子洲气田稳产的主力接替区块。研究区面积大，钻井数目少，地质认识程度低，尚处于开发评价阶段。以盒8段为研究对象，开展了沉积、储层等精细地质研究工作，并与苏里格致密砂岩气田进行综合对比，落实了有效砂体的厚度、规模、发育频率，总结了有效砂体在空间的分布规律，认识到区内有效砂体分布零星，连续性差，与心滩等优势相带对应关系较好，平面上主要集中在研究区的西砂带，垂向上在盒8上2、盒8下2小层相对发育。结合地质与试气资料，以“连续性有效厚度”为主要依据，将储层分成好、中、差、干层等4种类型，优选了富集区，按照开发级次将研究区划分为3类区，建议在一类区、二类区优选直井开发，不建议部署水平井开发。本研究为气田开发方案编制提供了地质依据，同时也可对类似气田的地质工作起到借鉴作用。
Abstract: Qingjian district is one of the most promising succeed blocks for stable production of Zizhou gasfield in eastern Ordos Basin. Because the study area is large with only a few drilling wells, the degree of geological knowledge is relatively low and the study area is still in the early stage of development evaluation. Taking He 8 reservoir as the research object, based on a series of fine geological research work such as sedimentary analysis and reservoir evaluation in a comprehensive comparison with Sulige tight sand gasfield, effective sand bodies thickness, scale, development frequency and distribution regularities were defined. Through analysis, it is clear that effective sand bodies scattered in space with poor continuity, have a good corresponding relationship with the distributions of the favorable sedimentary facies such as channel bars. The effective sand bodies are mainly concentrated in western sand belt in plane, and are more developed in the second layers of upper and lower submembers of He 8 member vertically. Combining geological information and production testing data, “continuous effective thickness” was chosen as the main parameter for reservoir evaluation, and reservoirs were classified into 4 types: good, medium, poor and dry layer. Then, enriched area was optimized, and the study area was divided into 3 types of zones according to different development potentials. It is recommended to deploy vertical wells in enriched zone and not to apply horizontal wells under the current technical and economic situation. This study provides a reliable geological basis for the preparation of gasfield development plan, and it is also of a certain reference significance to the geological research in the gasfields with similar conditions