川东地区寨沟湾构造嘉二段储层特征及平面分布规律

Reservoir characteristics and distribution of T_1j_2 of Zhaigouwan structure in eastern Sichuan

根据川东寨沟湾构造嘉二段地层钻井岩心的宏观及微观特征,结合常规孔、渗资料对其储层特征进行了较为深入的研究。结果表明:该套地层的储集岩岩性以晶粒白云岩为主,其次为颗粒白云岩;储集空间以次生成因的晶间孔、晶间溶孔为主;储集性能总体较差,多属于裂缝-孔隙型和孔隙-裂缝型储层;储层纵向上主要发育于嘉二2亚段,嘉二1亚段较少,嘉二3亚段部分含有储层;横向上,嘉二2亚段以寨沟2井和寨沟4井储层最为发育,嘉二1亚段以寨沟4井储层发育最好。此外,沉积作用不仅控制着储集岩体的发育和分布,还影响着储层的基本形态和经历的成岩作用类型及强度,是控制储层发育的主导因素;而成岩作用决定了储层内部储集空间的特征和储集性能,直接影响储集岩孔隙空间的形成和演化;构造作用则为以上作用提供了条件。

Based on the outcrop features and conventional petrophysical properties, the reservoir characteristics of Tj2 of Zhaigouwan structure in eastern Sichuan are studied. The result shows that the reservoir rocks are mainly composed of crystal grain dolomite and particle dolomite. The reservoir spaces are mainly intercrystal pores and dissolved pores. The reservoir properties are poor. The reservoir types are fracture-pore and pore-fracture. Reservoirs mainly developed in Tj2^2 along longititudinal direction, less in T1j2^1 and partly in Tj2^3. Reservoirs of T1j2^2 developed well in Zhaigou 2 well and Zhaigou 4 well, while reservoirs of Tjj2^-1 developed well in Zhaigou 4 well. Sedimentation not only controls the development and distribution of reservoir, but also affects the basic pattern of reservoir and the type and intensity of diagenesis. It is the dominated factor controlling the reservoir development. Diagenesis determines the reservoir space and reservoir performance, and directly influences the forming and evolution of pore space. Tectonism provides conditions for the above activities.