The genesis of quartz dissolution in tight sand reservoirs and its impact on pore development: A case study of Xujiahe Formation in the transitional zone of Central-Southern Sichuan Basin

被引：0

作者：

Liu, Jinku ^{[1
]}

Peng, Jun ^{[2
]}

Shi, Yan ^{[1
]}

Bao, Zuofan ^{[1
]}

Sun, Yongliang ^{[1
]}

Liu, Xuemin ^{[1
]}

Zhang, Ze ^{[1
]}

机构：

[1] Engineering Technology Research Institute, CNPC Bohai Drilling Engineering Company Limited, Tianjin

[2] School of Geoscience, Southwest Petroleum University, Chengdu, 610500, Sichuan

来源：

Shiyou Xuebao/Acta Petrolei Sinica | 2015年 / 36卷 / 09期

关键词：

Genetic mechanism; Metasomatic dissolution; Quartz dissolution; Secondary pores; Sichuan Basin; Tight sand reservoir; Xujiahe Formation;

D O I：

10.7623/syxb201509006

中图分类号：

学科分类号：

摘要：

By means of rock (casting) thin-section identification, scanning electron microscope and X-ray diffraction, a detailed study was carried out on the characteristics and genetic mechanism of quartz dissolution in tight sand reservoirs of Xujiahe Formation in transitional zone of the Central and Southern Sichuan Basin as well as its impacts on pore development. Research results have indicated that massive quartz dissolution existed along grain edges and secondary enlarged edges, as well as in the interior of grains. Quartz dissolution mainly took place in subage A2 of the middle diagenetic stage. There are two genetic mechanisms of quartz dissolution. One is the direct dissolution in alkali diagenetic environment with weak dissolution degree. The other is the metasomatic dissolution by clay minerals and carbonate minerals, of which the metasomatic dissolution of clay minerals against quartz grains is more intense. After the dissolution of quartz grains, a large number of secondary pores are formed to effectively increase reservoir spaces and improve pore structure as well as reservoir porosity and permeability. In particular, the secondary pores that were generated by metasomatic dissolution of clay minerals against quartz made considerable contributions to reservoir pores. ©, 2015, Science Press. All right reserved.

引用

页码：1090 / 1097

页数：7