陕北地区延长组长10_1储层成岩作用与成岩相

通过大量野外地质调查、钻井岩心观察和室内分析测试,对陕北地区长101储层的成岩作用和成岩相进行了研究。结果表明,研究区长101储层处于中成岩A期阶段,压实作用与碳酸盐、粘土(高岭石、伊利石)矿物胶结、浊沸石胶结和硅质胶结作用是造成储层原生孔隙丧失的主要原因;绿泥石胶结抑制孔隙充填,长石、浊沸石矿物的溶蚀作用使孔隙间的连通性得到改善,储层物性得到提高。成岩相类型可划分为8种,优质储层与成岩相关系密切,其中压实相、碳酸盐胶结相、粘土矿物胶结相、石英加大相、浊沸石充填相不利于储层的发育,而长石溶蚀相、绿泥石膜胶结相、浊沸石溶蚀相对储层物性的改善具有重要作用。

Diagenesis and diagenetic facies of the Chang 101 Reservoir in northern Shaanxi Province

Based on large quantities of field geological investigation, core observation and laboratory analysis, the authors studied in detail the diagenesis and diagenetic facies of Chang 101 reservoir in northern Shaanxi. The results show that Chang 101 reservoir of the study area is at stage A of middle diagenesis phase. Compaction and cementation by carbonate, clay minerals (kaolinite, illite), laumonite and silicon are the main factors for the loss of reservoir primary porosity. Chlorite cementation can prevent the pore from being filled. Dissolution of feldspar and laumonite minerals improves connectivity between pores. Physical properties of the reservoir are improved by these factors. There are eight types of diagenetic facies in this area. High quality reservoir is closely related to the diagenetic facies. Compaction facies, carbonate cementation facies, clay mineral cementation facies, quartz overgrowth facies and laumonite filling facies are unfavorable for the development of high quality reservoir. On the contrary, feldspar dissolution facies, chlorite cementation facies and laumonite dissolution facies play an important role in improving the physical properties of the reservoir.