柴西下干柴沟组咸化湖盆碳酸盐岩溶蚀模拟试验  

Dissolution simulation experiment of carbonate rock in saline lacustrine basin of lower Ganchaigou Formation in western Qaidam Basin

作　　者：张世铭[1,2] 袁剑英[1,2] 张小军[1,2] 张婷静[1,2] 郑永仙 王朴[1,2] 张博策 牟志进 应敏 ZHANG Shiming;YUAN Jianying;ZHANG Xiaojun;ZHANG Tingjing;ZHENG Yongxian;WANG Pu;ZHANG Boce;MOU Zhijin;YING Min(Northwest Branch of Research Institute of Petroleum Exploration and Development,CNPC,Lanzhou 730020,China;Key Laboratory of Reservoir Description,CNPC,Lanzhou 730020,China;Research Institute of Petroleum Exploration and Development,Qinghai Oilfield,CNPC,Dunhuang 736202,China;Second Oil Production Plant,Qinghai Oilfield,CNPC,Haixi 816400,China)

机构地区：[1]中国石油勘探开发研究院西北分院,甘肃兰州730020 [2]中国石油天然气集团公司油藏描述重点实验室,甘肃兰州730020 [3]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [4]中国石油青海油田分公司采油二厂,青海海西816400

出　　处：《中国石油大学学报（自然科学版）》2023年第1期1-11,共11页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金面上项目(42172169)。

摘　　要：为研究地层条件下有机酸对湖相碳酸盐岩基质微孔的改造作用及咸化环境沉积盐类矿物溶蚀对碳酸盐岩储层的影响,以柴达木盆地西部地区下干柴沟组湖相碳酸盐岩为例,采用高温高压模拟、扫描电镜及离子浓度测试等试验手段,依据岩心样品溶蚀模拟过程中矿物组分、物性、孔隙特征及反应液离子浓度的变化对咸化湖盆碳酸盐岩在有机酸作用下的溶蚀规律及控制因素进行研究。结果表明:酸性流体作用后碳酸盐岩样品物性均有一定改善,其渗透率增长明显;溶蚀过程中低温条件下发生与碳酸盐共生的石膏、芒硝及长石的溶解,方解石较白云石容易发生溶解,碳酸盐的溶解程度随温度升高具有先增强、后减弱的特点,存在“溶蚀窗”,相对封闭条件下,石膏等盐类矿物溶解产生同离子效应抑制碳酸盐的溶解;温度和水岩比是控制碳酸盐溶解的关键因素,水岩比决定发生反应的体系,不同体系下温度对溶蚀强度影响存在差异,低水岩比情况下温度升高碳酸盐趋于沉淀,中等水岩比情况下溶解强度随着温度升高先增强、后减弱,较高水岩比情况下温度升高利于碳酸盐溶蚀。Take the lacustrine carbonate of the Lower Ganchaigou Formation in the western part of the Qaidam Basin as an example to study the effect of organic acids on the matrix micropore of lacustrine carbonate and the influence of salt mineral dissolution on carbonate reservoirs in the salty environment under strata conditions, the effect of acidic fluids on minerals dissolution and reservoirs improvement was studied, and the law of dissolution and control factors was analyzed. Experimental methods such as high temperature and high-pressure simulation, scanning electron microscope and ion concentration test were used. Changes in composition, physical properties, pore characteristics, and ion concentration of the reaction solution during the dissolution simulation experiment were studied. The dissolution simulation experiment was the dissolution of acetic acid fluid on the core plunger sample in a relatively closed reactor. Results shows that after the action of acid liquid the physical properties of carbonate rock samples were improved, and their permeability increased significantly. Gypsum, Glauber? s salt, and feldspar are symbiotic with carbonate dissolved under low-temperature conditions. Calcite becomes dissolvable than dolomite. The degree of dissolution has the characteristics of first strengthening and then weakening, and increasing with temperature. Carbonate dissolution has the best dissolution temperature range. Dissolution of carbonate is inhibited due to the common ion effect in the dissolution of salt minerals such as gypsum, under relatively closed conditions. Temperature and water-rock ratio are the key factors controlling carbonate dissolution. The water-rock ratio determines the reaction system. There are differences in the influence of temperature on corrosion strength in different reaction systems. In the case of a low water-rock ratio, the carbonate tends to precipitate when the temperature rises. In the case of a medium water-rock ratio, the dissolution strength first increases and then decreases w

关 键 词：柴达木盆地 古近系下干柴沟组 湖相碳酸盐岩 高温高压溶蚀模拟 盐类矿物 

分 类 号：TE122.1[石油与天然气工程—油气勘探]