中等地温场、长深埋期石英砂岩类储层成岩作用与孔隙度演化模式——以鄂尔多斯盆地延安地区下石盒子组为例  

Diagenesis and Porosity Evolution Model of the Quartzose Sandstone Reservoir with Moderate Palaeogeothermal,Long Period of Large Buried-depth:A Case Form the Lower Shihezi Reservoir in Yan'an,Ordos Basin

作　　者：张创 罗然昊 张恒昌 周雪 王成龙 邢华 钱成 

机构地区：[1]延长油田股份有限公司志丹采油厂,陕西延安717500 [2]陕西延长石油(集团)有限责任公司,陕西西安710075

出　　处：《地球科学进展》2017年第7期744-756,共13页Advances in Earth Science

基　　金：国家自然科学基金项目"特低渗透双重介质砂岩微观孔隙结构的定量表征"(编号:41102081)资助~~

摘　　要：以鄂尔多斯盆地延安地区下石盒子组储层为研究对象,在储层成岩作用、埋藏史与热史研究的基础上,应用动力学模型与作用模拟方法分析了该区孔隙度演化史。结果表明,中等地温场、长深埋期煤系地层内的石英砂岩类储层,成岩早期孔隙介质呈酸性而缺乏早期碳酸盐胶结物,压实损失孔隙度较大;溶蚀作用产生了一定的次生孔隙,但长深埋期、较高地温环境下溶蚀产物沉淀为更为稳定的次生石英和黏土矿物,加之含铁碳酸盐胶结物的胶结与交代,造成粒间孔隙大量封闭的同时,又充填了部分溶孔;压实损失孔隙度较大的情况下,石英次生加大的普遍发育及黏土矿物与含铁碳酸盐胶结物的充填,往往造成此类储层为低渗—超低渗储层。This research took Lower Shihezi Reservoir in Yan＇an, Ordos Basin as research object. Based on the achievement of former scholars, the article first analyzed burial history and palaeogeothermal history. Furthermore, it analyzed the diagenesis characteristics and divided the diagenetic stages through the application of test data, such as thin section, SEM, cathode luminescence, x-ray diffraction, homogenization temperature of fluid inclusion, etc. Finally, the article analyzed and identified the initial porosity model and various kinds of porosity evolution model in the process of diagenetic, optimized the suitable method of Lower Shihezi Reservoir, established a calculation method that the porosity of reservoir increased in the process of dissolution by applying the effect simula- tion, simulated porosity evolution of reservoir in research area and analyzed the porosity evolution model. The re- suits showed that the reservoir of quartzose sandstone with moderate palaeogeothermal, long period of large buried- depth, carbonate cement was absent in early phase in the coal measure strata, and the porosity loss by compaction was substantial. Though secondary porosity was generated by dissolution, the quartz and clay mineral were precipi- tated from dissolution mass, which filled intergranular pores and dissolved pores. In addition to substantial porosity loss by compaction, the filling of massive quartz overgrowth, clay mineral, and ferrocarbonatite, always made such reservoirs to be low or ultra-low permeability reservoirs.

关 键 词：埋藏史 热史 孔隙度演化 次生石英 鄂尔多斯盆地 

分 类 号：P618.130.2[天文地球—矿床学] TE112.2[天文地球—地质学]