油井暂堵剂SJ-2室内实验及现场应用

Indoor experiment and field application of SJ-2 temporary plugging agent for oil wells

针对文明寨和卫城油田中低渗断块砂岩油藏部分储层水敏性强、作业过程中易受污染的问题,引进了SJ-2油井暂堵剂,从泵入性、膨胀性能、暂堵强度、溶解性能和渗透率恢复性能等5个方面进行室内评价实验。室内实验表明,SJ-2油井暂堵剂浓度在2%以内时流动性好、在水相砂岩上能承受的最大压力为7MPa,85℃温度下72h溶解率达到60%以上。矿场应用40井次,有效率达95%,作业后平均3.5d油井工况恢复正常。SJ-2油井暂堵剂可适用于文明寨和卫城油田中低渗油藏,可大幅度缩短排水期,能有效提高油井的生产时率。

In view of the problems of high water sensitivity and vulnerability to pollution of some pools in mid-low permeability sandstone reservoirs in Wenmingzhai and Weicheng Oilfields, SJ-2 temporary well plugging agent is introduced and indoor experimental evaluation is made from five perspectives as follows： pumping, swelling, temporary plugging, dissolving, and permeability recovery. Indoor experiments show that the SJ-2 temporary well plugging agent features in good mobility when the concentration is lower than 2%. The maximum pressure to bear on the aqueous sandstone is 7 MPa, and the 72 h dissolution rate at the temperature of 85 ℃ tops 60%. The agent has been applied to 40 wells, 95% efficient. The agent can also be used to the mid-low permeability reservoirs, shortening the drainage period substantially and improving the production rate of oil wells effectively.