构造期溶蚀作用对储层的改造及其意义

THE DISSOLUTION IN THE PERIOD OF STRUCTURE FORMATION IN THE REWORKING OF THE GAS RESERVOIR AND ITS GEOLOGICAL SIGNIFICANCE IN SICHUAN REGIN

根据川东黄草峡气田嘉二~2碳酸盐岩储层溶蚀特征、孔隙充填矿物顺序与矿物包裹体均一温度间关系,认为该储层在构造期(褶皱上升时期)发生过三期溶蚀作用。它的意义在于:(1)储层溶孔发育期与构造形成期,生气高峰及聚集期相一致,有利于气藏的形成;(2)三期溶孔叠加使碳酸盐岩储层物性变好;(3)为解释构造控制储层物性变化提供依据;(4)成岩作用研究与构造活动相联系,有益于指导油气勘探。

Based on the relations between the dissolution characteristics, the sequence of minerals filled in the pores and the homogenetic temperature of the inclosures in T_1j_2~2 carbonate reservoir of Huangcaoxia gas field in Eastern Sichuan, it is suggested that the reservoir had been subjected to dissolution for three times during the formation of the structure(during the uplifting of the fold). Its significance are: (1) the period of development of solution pores is in consistent with that of structure forming and the peak of generation and accumulation of the gas ,which is favorable for the formation of gas reservoirs; (2) the superposition of the solution pores formed in three times improves the petrophysical properties of the carbonate reservoir; (3) the reasons that the structures control the variations of the petrophysical properties of the reservoir are explained; (4) the study of diagenesis is connected with the structure movement, which is favorable for directing the oil and gas exploration.