黏土矿物类型对低矿化度水驱采收率的影响实验  

Experiment of the impact of clay mineral types on recovery by low salinity waterflooding

作　　者：尉雪梅[1,2] 张艳玉 蒋文超[1,2] 孙晓飞 WEI Xuemei;ZHANG Yanyu;JIANG Wenchao;SUN Xiaofei(School of Petroleum Engineering,China University of Petroleum,Qingdao 266580,China;MOE Key Laboratory of Unconventional Oil&Gas Development,China University of Petroleum,Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]非常规油气开发教育部重点实验室(中国石油大学(华东)),山东青岛266580

出　　处：《大庆石油地质与开发》2022年第5期120-129,共10页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“长水平井段SAGD多点均匀注汽方式与工艺研究”(2016ZX05031-002);国家自然科学基金项目“稠油油藏人工泡沫油强化混合气体吞吐方法及其机理研究”(51604293)。

摘　　要：为定量表征不同黏土矿物对低矿化度水驱效果影响程度,分析低矿化度水驱的作用机理,采用黏土悬浮液对石英颗粒表面的高温黏附技术,制作了石英颗粒表面附着不同黏土矿物的填砂模型,并开展了岩心驱替实验和Zeta电位、接触角测试实验。结果表明:低矿化度水驱对纯石英砂填砂模型提高采收率效果不明显,黏土矿物的存在是低矿化度水驱提高采收率的必要条件;附着高岭石的石英砂模型的水驱采收率随注入水矿化度的降低呈提高趋势,附着蒙脱石的石英砂模型的水驱采收率在初期也随矿化度降低而逐渐升高,但存在一个最高采收率的临界矿化度,其后随注入水矿化度的进一步降低,最终采收率又呈现降低趋势;而蒙脱石黏土遇低矿化度水后,会使附着原油的蒙脱石颗粒膨胀运移而提高洗油效率,但随着离子质量浓度的降低,脱落的微粒增多,堵塞渗流通道,又会影响水驱效果;附着混合黏土岩心和附着蒙脱石岩心具有相似的水驱采收率变化规律,附着混合黏土的岩心模型的水驱效果要好于附着单一黏土矿物的岩心模型。In order to quantitatively characterize the influence on low salinity waterflooding(LSWF)effects for different clay minerals and analyze the acting mechanism of LSWF,with the help of high temperature adhering technique of quartz particles surface by clay suspension,sand packed models are prepared for quartz particle surface adhered by different minerals,and core flooding experiments and experiments of Zeta potential and contact angle are carried out. The results show that LSWF has little effects for enhanced oil recovery of pure quartz sand packed model,existence of clay mineral is the necessary condition for enhancing LSWF recovery. Waterflooding recovery factor of quartz sand model attached with kaolinite increases singly with decrease of injected water salinity and recovery factor of quartz sand model attached with montmorillonite also gradually increases with salinity decrease in the initial stage,but there is a critical salinity with the highest recovery. With further decrease of injected water salinity,the ultimate recovery shows a trend of decrease. When montmorillonite meets with low salinity water,its particles will expand and migrate,thus enhance oil displacement efficiency. However,with decrease of ionic concentration,more micro-particles will fall off and block the flow path,which will influence waterflooding effects. Cores with attached mixed clay have similar change laws of waterflooding recovery with cores with attached montmorillonite,and core model with attached mixed clay has better waterflooding effect than that with attached single clay.

关 键 词：黏土矿物 低矿化度水驱 岩心驱替实验 采收率 ZETA电位 

分 类 号：TE32[石油与天然气工程—油气田开发工程]