新都-洛带气田侏罗系遂宁组第二段致密砂岩储层特征

Study on reservoir characteristics of Member 2 of Jurassic Suining Formation in the Xindu-Luodai gas field,Sichuan,China

通过岩心观察，结合区域地质资料，利用薄片资料、扫描电镜资料、岩屑录井资料、孔渗资料及压汞实验分析，表明新都-洛带气田侏罗系遂宁组第二段储层岩石主要是岩屑长石砂岩和长石岩屑砂岩，由于机械压实作用、压溶作用、胶结作用、溶蚀作用、交代作用等成岩作用影响和沉积作用控制，储层砂岩属特低-超低孔、低渗-超低渗致密砂岩储层，平均孔隙度4．67％，渗透率0．420×10^-3μm^2，孔渗相关性好。河道迁移改道造成储层砂岩中泥质隔夹层发育，遂二段主力产层J3sn2^1储层砂层组中隔夹层达到15％～40％，分布频率为0．18～0．40m^-1。隔夹层厚度相对较大，发育频繁，导致储层非均质性增强，储层发育主要受沉积相带、成岩作用等影响。处于有利相带的构造高部位是优质储层的发育区，有望取得油气勘探突破。

Based on the observation of cores and cutting logging analysis, combined with the regional geologic data, and using thin section analysis, porosity and permeability data and mercury injection experiments analysis the authors find that the sandstones of Member 2 of Jurassic Suining Formation in the Xindu-Luodai gas field, with fine sorted and sub angular roundness, consist of feldspar litharenite and litharenite. The diageneses occurred in the sandstones are mainly compaction and cementation and dissolution. The sandstones are of low porosity with a mean of 4.67% and of low permeability with a mean of 0. 420 × 10^-3 μm^2 because of their sedimentation and diageneses. The distributary channels range very widely, and the insulating layer and interlayer develop well, with the insulating layer and interlayer distribution densit and interlayer distribution reservoir geophysics varies frequency rangings f widely, and seriously y ranging from 15%～40% and the insulating layer rom 0. 18～0. 40 m^-1. This points out that the affectes the gas accumulation and exploration.