纳米排水剂对致密岩心的作用机理  

Mechanism of nano-drainage agents on tight core

作　　者：秦国伟 刘青萍 徐文波[2] 吴梅[3] 秦文龙[1] 罗明良[4] 白艳明[5] QIN Guowei;LIU Qingping;XU Wenbo;WU Mei;QIN Wenlong;LUO Mingliang;BAI Yanming(College of Petroleum Engineering,Xi’an Shiyou University,Xi’an City,Shaanxi Province,710065,China;No.3 Oil Production Plant,PetroChina Daqing Oilfield Co.,Ltd.,Daqing City,Heilongjiang Province,163113;PetroChina Research Institute of Petroleum Exploration and Development,Beijing City,100083,China;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China;Exploration and Development Research Institute,PetroChina Daqing Oilfield Co.,Ltd.,Daqing City,Heilongjiang Province,163712,China)

机构地区：[1]西安石油大学石油工程学院,陕西西安710065 [2]中国石油大庆油田有限责任公司第三采油厂,黑龙江大庆163113 [3]中国石油勘探开发研究院,北京100083 [4]中国石油大学(华东)石油工程学院,山东青岛266580 [5]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《油气地质与采收率》2022年第5期126-132,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家自然科学基金项目“离子水驱砂岩油藏固/液体系界面调控及残余油启动机制研究”(52174027);陕西省自然科学基金项目“低渗气藏绿色纳米排水剂控水采气作用机制研究”(2020JM-534);“可回收高分子磁纳米材料与VES流体的超分子自组装机理研究”(2019JM-108);东北石油大学提高采收率教育部重点实验室项目“低渗气/水同层功能型控水剂研制及其作用机制研究”(NEPUEOR-2019-04)。

摘　　要：常规排水采气和控水采气技术难以解决致密气藏的低孔、低渗透和小孔喉等问题,为此采用转相技术制备适合致密气藏的纳米排水剂来改变岩石表面性质,提高致密气藏的排水效果。基于自制纳米排水剂和致密岩心,利用现代测试技术,探究纳米排水剂对岩心薄片及其粉末的作用机制,评价其对岩心润湿性及微观形貌的影响,并探讨纳米排水剂的排水采气作用机理。结果表明:纳米排水剂与岩心表面并未发生化学作用,仅通过静电和氢键等作用吸附于岩心表面形成疏水膜,从而降低岩心表面粗糙度,减小岩心孔隙中渗流阻力,达到排水采气的目的。同时纳米排水剂可使储层润湿性发生反转,即毛管压力变为阻力导致排出的地层水很难再次渗流至储层中,延长了排水采气有效期。The conventional drainage gas recovery and water-controlled gas recovery techniques are difficult to solve the problems of low porosity,low permeability,and small pore throats in tight gas reservoirs.For this reason,the phase inver⁃sion technology is utilized to prepare nano-drainage agents suitable for tight gas reservoirs to change the rock surface char⁃acteristics and improve the drainage effects of tight gas reservoirs.On the basis of self-prepared nano-drainage agents and tight cores,this paper explored the action mechanism of nano-drainage agents to core slices and their powder by modern testing technology and evaluated the effects on core wettability and microscopic morphology.The drainage gas recovery ac⁃tion mechanism of nano-drainage agents was then discussed.The results show that instead of reacting chemically with the core surface,the nano-drainage agent is only adsorbed on the core surface by electrostatic and hydrogen bonding effects to form a hydrophobic film,which can reduce the core surface roughness and the flow resistance in the pores to achieve drain⁃age gas recovery.At the same time,the nano-drainage agent can reverse the core wettability in the reservoir,namely that the capillary pressure becomes a resistance to prevent the discharged formation water from flowing into the reservoir again,extending the validity period of drainage gas recovery.

关 键 词：排水剂 致密气藏 排水采气机理 润湿性反转 接触角 

分 类 号：TE377[石油与天然气工程—油气田开发工程]