鄂尔多斯盆地演武油田延9段油藏低阻成因分析

Genetic analysis of low resistivity in Yan 9 reservoir of Yanwu Oilfield, Ordos Basin

刘之的,刘一仓,王联国,胡克来,吴泽民,康永梅

西安石油大学地球科学与工程学院，陕西 西安 710065 西安石油大学陕西省油气成藏地质学重点实验室，陕西 西安 710065 中国石油长庆油田分公司第十一采油厂，甘肃 庆阳 745000

College of the Geoscience and Engineering, Xi′an Shiyou University, Xi′an 710065, China Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi′an 710065, China No.11 Oil Production Plant, Changqing Oilfield Company, PetroChina, Qingyang 745000, China

近年来的勘探开发实践表明，鄂尔多斯盆地演武地区侏罗系延9段地层普遍发育低阻油藏，该类油藏受制于成藏和成岩条件，具有不同的成因。为探明低阻油藏富集区并进行优质高效开发，必须查明低阻油藏的成因，以有针对性地进行低阻油藏测井识别。文中充分利用研究区分析化验、生产动态等资料，从地层水矿化度、束缚水饱和度、矿物成分及钻井液侵入情况等角度，采用地质统计分析方法，深入剖析了低阻油藏的成因。研究表明：研究区地层水矿化度普遍较高，高地层水矿化度是形成低阻油藏的主要因素；泥质体积分数较高、岩性细及孔隙结构复杂，也会导致部分储层出现低阻现象；矿物成分和钻井液侵入对研究区影响相对较小。该研究成果可为研究区低阻油藏测井识别提供理论依据。

The exploration and development in recent years show that low resistance reservoirs are generally developed in Jurassic Yan 9 Formation in Yanwu area of Ordos Basin, which are subject to reservoir forming and diagenesis conditions, showing low resistivity reservoirs with different genesis. In order to explore the rich area of low resistance reservoirs and carry out high quality and efficient development, it is necessary to find out the origin of low resistance reservoirs so as to conduct targeted logging identification of low resistance reservoirs. This paper makes full use of the data of analysis and production performance in the study area, and through analysis of the origin of low resistance reservoir from four aspects of formation water salinity, irreducible water saturation, mineral composition and mud invasion by geologic statistical analysis method. The results show that the formation water salinity is generally high in the study area, and the high formation water salinity is the main factor for the formation of low resistance reservoir. High shale content, fine lithology and complex pore structure also lead to low resistivity of some reservoirs. Mineral composition and mud intrusion have relatively little influence in the study area. The research results can provide a theoretical basis for logging identification of low resistance reservoir in the study area.

10.6056/dkyqt202104012