和田河气田奥陶系碳酸盐岩成岩作用及孔隙演化

奥陶系碳酸盐岩储层是塔里木盆地和田河气田的主要产层 ,受成岩作用的改造非常强烈。通过对岩心、普通薄片、铸体薄片、阴极发光、碳氧同位素、微量元素和流体包裹体等多种资料进行综合研究 ,详细阐述了主要成岩作用的形成机理及其产物 ,分析了其对储层的影响和成岩序列。胶结作用和压实作用是原生孔隙和部分次生孔隙的主要破坏者 ;溶蚀 (岩溶 )作用、压溶作用、破裂作用和白云石化作用是次生孔隙的主要建造者 ,它们产生的溶孔、溶洞和裂缝是天然气的主要储集空间和运移通道。成岩作用是该储层物性的主要控制因素 ,它控制了孔隙的演化过程。

DIAGENESIS AND POROSITY EVOLUTION OF THE ORDOVICIAN CARBONATE ROCK IN HETIANHE GAS FIELD, TARIM BASIN

The Hetianhe gas field is a new and large gas field in Tarim Basin. The carbonate rock of Ordovician is the principal reservoir. It has been recreated intensely. Based on the observation and study of a large number of cores and sections, cathodoluminescence; petrography, stable isotopes of carbon and oxygen, microelements, fluid inclusions and so on, this paper expounds in detail the diagenesis and its influence on the reservoir, diagenetic sequences and porosity evolution of the Ordovician carbonate rock in the research area. Cementation and compaction have distroyed almost all primary pores and partly secondary pores. Solution, dolomitization, fracture and pressure solution have created a lot of secondary pores, caves and seams which are the principal reserve rooms and migration ways of gas. Diagenesis controlls the reservoir properties of carbonate rock and the process of porosity evolution.