气湿反转解除裂缝-基质液锁的实验研究  

EXPERIMENTAL STUDY ON REMOVING FRACTURE-MATRIX LIQUID LOCKING BY GAS-WETTING AGENT

作　　者：王斌 汪杰 姚二冬 周福建 张乐 魏慧蕊 李秀辉[2,3] WANG Bin

机构地区：[1]新疆油田公司工程技术研究院 [2]中国石油大学(北京)非常规天然气研究院 [3]中国石油大学(北京)油气资源与探测国家重点实验室 [4]西部钻探井下作业公司

出　　处：《钻采工艺》2019年第4期57-59,73,共4页Drilling & Production Technology

基　　金：国家科技重大专项“碳酸盐岩储层难动用储量高效改造关键技术研究”(编号:2016ZX05030005-002)

摘　　要：地层凝析液和外来流体在致密砂岩凝析气藏储层中形成液锁效应大大降低气井产量是其开采过程中面临主要问题之一。通过填砂管模型模拟压裂后形成的支撑裂缝与基质岩心驱替实验,评价气润湿反转剂CRS-850对裂缝-基质双重介质“液锁”损害解除效果,得出如下结论:氟碳类气润湿反转剂CRS-850可实现岩心表面润湿性由强水湿性转变为气相润湿,处理后岩心端面“气-液-固”平均润湿角从33.3°增大到101.2°;气润湿反转剂显著提高岩心内部液相渗流能力,增加气驱渗透率,岩心气驱渗透率恢复效果显著,在气驱盐水基础上提高了501.69%~673.91%,表明气润湿反转剂有利于致密砂岩储层解除“液锁”损害;气润湿反转剂可进一步解除填砂模型模拟压裂后形成的支撑裂缝液锁损害,填砂管模型渗透率越低,气驱排水率越高,润湿性改变后的气驱排水率提高幅度也越大;同时,气润湿反转剂有利于解除压裂后形成的裂缝-基质岩心双重介质中液相损害,有效恢复率达19.47%。Formation condensate and extraneous fluid form a strong liquid-locking effect in tight sandstone condensate reservoirs,reducing the production of gas wells,it is one of the main problems faced in production. The sand-filling pipe model was used to simulate the prop fracture after fracturing and the matrix core displacement experiments was done to evaluate the effects of the gas-wetting reversal agent CRS-850 to remove the fracturematrix dual media"liquid lock"damage. The following conclusions were obtained. The fluorocarbon gas wetting reversal agent CRS-850 could change the wettability of the core surface from strongly water wetting to gas wetting. After treatment,the average wetting angle of the gas-liquid-solid end face increased from33. 3° to 101. 2°,the gas-wetting reversal agent significantly increased the internal liquid-phase percolation capacity of the core,increased the gas-driving permeability,and had a significant recovery effects on the permeability of the gas-flooded core,which was increased by 501. 69% to the gas-driven salt water to673. 91%,indicating the gas-wetting reversal agent was beneficial to the release of"liquid-locking"damage in tight sandstone reservoirs. The gas-wetting reversal agent could further relieve the liquid lock in support crack formed by the sand filling model after the fracturing,and the hydraulic permeability of the sandfilled pipe model was increased. The lower the permeability of the sand filling pipe model,the higher the gas flooding rate,and the greater the increase in gas flooding drainage rate after the change in wettability. At the same time,the gas-wetting reversal agent was beneficial to release the liquid phase damage formed by the fracturing in the fracture-matrix core.

关 键 词：气润湿 裂缝-基质 气测渗透率 填砂管 

分 类 号：TE3[石油与天然气工程—油气田开发工程]