摘要
为了研究注盐酸对致密砂岩气藏微观孔径分布的影响,通过核磁共振、CT扫描及X射线衍射分析等技术,对盐酸处理前后的岩心微观孔喉分布和物性变化进行分析,揭示盐酸处理致密砂岩气藏对微观物性改变的机理。研究结果表明,盐酸在储层条件下可以溶蚀砂岩中的伊利石、伊/蒙间层、方解石和白云石等矿物,酸液溶蚀后岩心的孔隙度和渗透率均有一定程度增大,孔隙度的增大幅度小于渗透率的增大幅度,孔隙度的增大幅度为11.73%~36.08%,渗透率的增大幅度为36.81%~63.64%。岩心中的矿物成分对酸化后的储层物性改善程度影响较大,方解石和白云石等碳酸盐岩矿物含量越高,盐酸酸化后的物性改善效果越好。砂岩经过盐酸处理后,孔径分布发生明显改变,酸化后微孔和小孔所占的孔隙体积增多,孔喉连通性得以改善,岩心的孔隙度和渗透率提高。
The microscopic pore-throat distribution and physical property changes of tight sandstone gas reservoir after treated by hydrochloric acid were analyzed by means of nuclear magnetic resonance,CT scanning and X-ray diffraction analysis,revealing the mechanism of physical property change of tight sandstone gas reservoir.The results show that hydrochloric acid can dissolve illite,illite-smectite interbedding,calcite,dolomite in sandstone under reservoir conditions,which can increase the porosity and permeability of rock samples to a certain extent.The increase of porosity is less than that of permeability,and they are 11.73%~36.08%and 36.81%~63.64%separately.The mineral composition of rock samples has a great influence on the improvement degree of reservoir physical properties by acidification.The higher the content of carbonate minerals such as calcite and dolomite,the better the improvement effect of reservoir physical properties after acidification.After the sandstone is treated with hydrochloric acid,the pore size distribution changes significantly,the pore volume occupied by micropores and small pores increases,which makes the connectivity of pore throat improved,so the porosity and permeability of the core are improved.
作者
赵金省
黄晓东
马景洋
李攀
侯瑞
ZHAO Jinsheng;HUANG Xiaodong;MA Jingyang;LI Pan;HOU Rui(School of Petroleum Engineering,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China;Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China;No.6 Oil Production Plant,PetroChina Changqing Oilfield Company,Dingbian,Shaanxi 718606,China;No.3 Gas Production Plant,PetroChina Changqing Oilfield Company,Wushenqi,Inner Mongolia 017300,China;Natural Gas Evaluation Project Department,PetroChina Changqing Oilfield Company,Qingyang,Gansu 745000,China)
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2023年第3期55-61,共7页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家自然科学基金项目“致密砂岩油藏CO 2吞吐多尺度流、固物性变化机理及其对吞吐效果的影响”(52174031)
陕西省自然科学基础研究计划项目“致密砂岩油藏CO 2吞吐效果微纳米尺度主控因素研究”(2021JM-411)。
关键词
储层物性
孔隙半径分布
注盐酸
致密砂岩气藏
reservoir physical property
pore size distribution
hydrochloric acid injection
tight sandstone gas reservoir
