鄂尔多斯盆地上古生界致密砂岩储层微观孔隙特征

陕西延长石油(集团)有限责任公司,陕西 西安 710075

地质资源与地质工程; 鄂尔多斯盆地; 上古生界; 微观孔隙结构特征; 成岩作用

Micro-characteristics of Upper Paleozoictight reservoir of Ordos Basin
YU Bo

(anxi Yanchang Petroleum(Group)Co.,Ltd.,Xi'an 710075,China)

geological resources and geological engineering; Ordos Basin; Upper Paleozoicerathem; micro-pore structure; diagenesis

DOI: 10.13800/j.cnki.xakjdxxb.2018.0121

备注

鄂尔多斯盆地上古生界致密砂岩储层聚集了丰富的天然气资源,其作为一种重要的接替资源逐渐成为勘探开发的热点。通过储层岩心分析,结合压汞实验研究其孔喉结构特征,得到储层孔隙空间展布及地下微观特征,进而对比分析3种成岩作用对于储层孔隙特征的影响,结果表明:鄂尔多斯盆地上古生界致密砂岩储层主要发育粒间孔隙、粒内溶孔、晶间孔和微裂缝4类孔隙; 盒8和山1的主要孔隙类型是粒内溶孔和晶间孔; 山2则是粒间孔,其次是晶间孔和粒内溶孔,其所占比例相当。3种成岩作用对储层孔隙特征都有很强的改造作用。其中压实作用对于孔隙度影响最大,溶蚀作用影响最小。强烈的压实作用也导致储层的微孔率很高。

Gas resources in Upper Paleozoic tight reservoir,Ordos Basin are rich,which as an important complement resource,is gaining more and more attention.By obersving cores,identifying casting lamella,scanning electron microscope and mercury porosimetry technique,the special micro-pore structure of tight-sand reservoir was researched.A contrastive analysis of the effect on pore characteristics by different kind of diagenesis was carried out.The results show that: four types of pores are intergranular pores,dissolved intra-grain pores,intercrystalline pores,and micro-fractures develop in Ordos Basin.The main pore type of He 8 and Shan 1 is dissolved intra-grain pores and intercrystalline pores while that of Shan 2 is intergranularpores.Those three types of diagenesis have great influences on pore-characteristics with compaction rendering most while dissolution least.Great compaction leads to a high level of reservoir micro-pore.