川中磨溪-龙女寺雷口坡组雷三段储层研究

The Reservoir Research of 3rd-section of Leikoupo formation in Moxi-Longnvsi region of Central Part of Sichuan Basin

根据取心段的宏观及微观观察,结合压汞分析、薄片鉴定、测井识别等各种测试资料,对磨溪-龙女寺地区雷三段储层的基本特征和主控因素进行了分析,认为其储层集中分布在雷三段的上部,储层岩性以粉晶白云岩为主,砂屑白云岩较少;储渗空间以晶间孔、晶间溶孔和片状喉道常见,粒间溶孔和缩颈喉道少见;物性较差,多属于中孔低渗的裂缝-孔隙型储层。储层主要受到沉积和成岩作用的共同影响,其中局限台地是最有利于储层形成与演化的沉积相带,其次是台内点滩,储层多属于这些相带的沉积物经过后期白云石化、重结晶、埋藏溶蚀和构造作用改造后的产物。研究成果为研究区下一步的勘探部署提供了一定的地质依据。

Based on the macroscopic and microscopic observation about drilling cores, the essential charabteristics and main controlling factors of the 3rd-section of Leikoupo formation of Middle Triassic in Moxi-Longnvsi region have been analyzed with kinds of analyses or test materials such as analysis of mercury intrusion capillary pressure, thin section observe, Logging identification and so on. Study shows that the favorable reservoir mainly distributes in the upper part of 3rd section of Leikoupo formation, and it consists of more powder crystalline dolostone and less dolarenite. Inter-crystaUine pore, dissolved inter-crystalline pore and lamellar throat are common in reservoir space, while dissolved intergranular pore and neck throat are subordinate. The reservoir belongs to the fracture-pore type of moderate porosity and low permeability, owing to the poor physical property. Study shows that the reservoir results from the interactive influence of sedimentation and diagenesis. Restricted platform is the most favorable sedimentary belt to the formation and evolution of reservoir and then comes the intraplafform point beach. Reservoir belongs to the product that remoulded by sediments in these facies belts through late dolomitization, recrystallization, burial dissolution and tectonic action. The study results provide a certain Geological basis for next exploration in study area.