适于渤海油田修井作业的暂堵液筛选与应用

Optimization and application of temporary plugging fluid for workover in Bohai oilfield

针对渤海油田修井过程中的成本和储层保护问题,优选了一套适于修井作业的暂堵液体系。暂堵液配方为生产水+0. 8%增黏剂ZC-VIS+2. 0%降滤失剂ZC-LS+8%暂堵剂ZC-ZD。暂堵液性能评价结果表明,暂堵液体系在80℃下可以稳定12 d,暂堵液封堵后体系的承压能力在9 MPa以上。岩心封堵性能结果表明,直接返排后岩心平均渗透率恢复值在85%左右,切片后岩心渗透率恢复值在90%以上。暂堵液在渤海某油田修井过程中现场应用2井次,均一次堵漏成功,启泵生产稳定后产能为修井前的95%以上,现场应用储层保护效果良好。暂堵液成本较现用暂堵液体系单位成本降低20%以上,经济效益显著。

To solve the high cost and reservoir protection problems existed in workover operations in Bohai oilfield,a temporary plugging liquid system suitable for workover operation is optimized.The formula of temporary plugging fluid is as follows:production water,0.8%ZC-VIS tackifier,2.0%ZC-LS filtration loss reducer and 8%ZC-ZD temporary plugging agent.Performance evaluation shows that the temporary plugging fluid can be stabilized for 12 days at 80°C,and the pressure-bearing capacity of the system after temporary plugging fluid exceeds 9 MPa.Core plugging performance show that the permeability recovery value of the core after direct returning is about 85%,and the core permeability recovery rate after slicing is above 90%.When the temporary plugging liquid is applied for 2 times of wells workover in Bohai oilfield,both are successful once time.The production capacity after workover exceeds 95%that before workover,and the field application exhibits good effect in reservoir protection.The temporary plugging liquid has remarkable economic benefit with a cost reducing 20%or more than current temporary plugging liquid.