川东北地区二叠-三叠系深层礁滩储层发育机理 段金宝1, 季春辉1 ...
- 格式：doc
- 大小：29.00 KB
- 文档页数：1
川东北地区二叠-三叠系深层礁滩储层发育机理
段金宝1, 季春辉1, 张学丰2
（1.中国石化勘探分公司,成都610041;
2.北京大学石油与天然气研究中心,北京100871）
［摘要］探讨川东北地区二叠-三叠系礁滩相储层孔隙形成过程与保存机理，通过对普光、元坝气田礁滩相优质储层的岩石学特征、储集空间类型、物性特征以及储层发育机理的研究，运用统计学分析手段，结果表明：①四川盆地东北部二叠-三叠系礁滩相储集岩性以残余生屑结晶白云岩、残余生物礁结晶白云岩、礁灰岩、残余鲕粒结晶白云岩为主，糖粒状白云岩及粉细晶白云岩次之，亮晶鲕粒灰岩最少。
储层类型以孔隙型为主，裂缝-孔隙型次之，Ⅱ、Ⅲ类储层居多，Ⅰ类储层较少。
②礁滩优质储层受沉积环境的控制，早期暴露溶蚀、白云岩化作用为储层基质孔隙发育奠定基础，后期烃类充注为储层孔隙保存提供保障，晚期裂缝改善储层的渗透性。
③川东北礁滩型储层孔隙以原生孔隙和早期次生溶孔为主，早期成岩作用贡献大，快速埋藏及烃类及时充注，使得储层孔隙得到很好的保存。
构造应力缝及液态烃深埋裂解形成的超压缝，改善了储层渗透性。
［关键词］礁滩储层；储层特征；孔隙保存机理；成岩作用；孔隙演化Development mechanism of reef reservoir of the Permian and
Triassic strata in northern Sichuan Basin, China
DUAN Jin-bao1, JI Chun-hui1, ZHANG Xue-feng2
1.Southern Exploration Company of SINOPEC, Chengdu 610041, China;
2.Institute of Oil & Gas, Peking University, Beijing 100871, China
Abstract:The lithological characteristics, reservoir space types and physical properties of reef reservoir from the Permian and Triassic strata in northeast Sichuan Basin is studied by application of statistics so as to understand the formation process and preservation mechanism of the reservoir pores. It shows that the reservoir rocks mainly consist of residual bioclastic dolomite, residual reef dolomite, reef limestone, residual oolitic dolomite, with some sucrosic dolomite, crystal powder dolomite and with minor spariteoolitic limestone. Quality reservoir is controlled by depositional environment and the development of reservoir pores is resulted from the early dissolution due to exposure and shallow buried dolomitization, and the timely post hydrocarbon filling play an important role in the preservation of reservoir pore, while the late formed fractures improve the permeability of reservoir. It reveals that the reef-shoal reservoir pores in northeastern Sichuan Basin are mainly primary pore and early secondary solution pore, and the early diagenesis makes obvious contribution on the formation of pores. Quick burial and timely hydrocarbon filling are decisive factors for the preservation of pores. Cracks induced by tectonic stress and overpressure cracks induced by deep burial of liquid hydrocarbons greatly improve the permeability of reservoir.
Key words: reef reservoir; reservoir characteristics; porosity preservation mechanism; diagenesis; porosity evolution。
