摘要
致密气藏物性差,只有通过水力压裂才能获得工业产能。在压裂过程中,水相压裂液侵入储层后会产生水锁现象,对储层造成伤害,严重影响致密气藏的产量。在压裂液中添加防水锁剂可以有效降低水锁带来的伤害。为了揭示防水锁剂降低水锁提高产量的机理,以稀释微乳液(DME)为例,首先通过表面张力实验,测试了DME的表面张力随浓度的变化关系,并得到最佳的添加浓度;然后通过接触角实验评价了DME的改变润湿性作用;之后结合自发渗吸和渗透率恢复率实验证明了DME的降水锁功能;同时借助核磁共振研究了渗吸过程中水相进入不同大小孔喉的顺序以及渗吸采收率。建立了一种有效评价防水锁剂的方法,为现场施工筛选此类添加剂提供了指导。
Due to the low permeability and porosity,effective development of tight gas reservoirs can only rely on hydraulic fracturing.During fracturing,the fracturing fluid enters pore and pore throat,which will create the water blockage therein and decrease the well productivity.Adding additives in the fracturing fluid is an effective method to reduce the water blockage.In order to find out the mechanism behind this method,several experiments were conducted and the diluted micro-emulsion(DME)was chosen as an additive.Firstly,surface tension test was conducted to acquire the relationship between the concentration of additive and surface tension,thus to obtain the optimal usage of additive.Secondly,the contact angle test was conducted to test the wettability alteration by the DME.Thirdly,imbibition and permeability recovery tests were conducted to test if the DME could reduce the water blockage.Moreover,the distribution of water in large and small pores were obtained through the nuclear magnetic resonance.Moreover,a systematic method was established to screen the additive for reducing the water blockage during hydraulic fracturing.Meanwhile,the key properties of such type of additive was revealed.
作者
梁天博
梁星原
王洪达
马实英
朱兴旺
吕玲玲
侯堡怀
LIANG Tian-bo;LIANG Xing-yuan;WANG Hong-da;MA Shi-ying;ZHU Xing-wang;Lü Ling-ling;HOU Bao-huai(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;Research Institute of Oil Production Engineering in Daqing Oilfield,Daqing 163453,China)
出处
《科学技术与工程》
北大核心
2020年第28期11568-11573,共6页
Science Technology and Engineering
基金
国家“十三五”科技重大专项(2016ZX05051-03,2016ZX05030-05)
国家自然科学创新研究群体项目(51521063)
中国石油科技创新基金(2018D-5007-0205)
中国石油大学(北京)引进人才科研启动基金(2462017YJRC031)。
关键词
渗吸
接触角
防水锁
核磁共振
imbibition
contact angle
water blockage reduction
nuclear magnetic resonance
