高渗稠油油田保护储层修井液的研发

Development of Reservoir Protection Workover Fluid for High Permeability Heavy Oilfield

徐国雄 陈华兴 庞 铭 徐方雪

XU Guoxiong CHEN Huaxing PANG Ming XU Fangxue

高孔高渗的渤海 S稠油油田采用水源井水修井后，漏失量大、产能恢复效果差。为了降低外来工作液对储层的损害，开发了保护储层的修井液体系。通过室内实验优选了配制前置液所用的边界膜清洗剂、降黏剂、阻垢剂和助排剂，评价了暂堵液的增黏性及其对岩心的封堵性能和破胶后岩心渗透率的恢复率。研究结果表明，配方为 15%边界膜清洗剂 GXXJ+1.5%降黏剂 JN-01+0.5%阻垢剂 ZG-02+1%助排剂 ZP-01的前置液的洗油率、降黏率均达到 90%以上，能够抑制钙镁垢形成，可将返排压力降低 50%以上。配方为 3%油溶性暂堵剂 BH-ZD+0.7%增黏剂 BH-VIS+3%破胶剂 JPC（海水配制）的暂堵液在压力 3.5～ 4 MPa、温度 60℃的条件下封堵效果良好，破胶后岩心的渗透率恢复率在 80%以上。采用该前置液加暂堵液体系修井能够有效预防有机质沉淀、油水乳化和无机垢堵塞等储层伤害。该体系已在 S油田应用，修井后工作液漏失量低且产能恢复较好。表 9参 9

when workover operations were performed in Bohai S oilfield，a high permeability and porosity heavy reservoir，using source water as workover fluid，there was the problem of large amounts of fluid leak into formation and poor productivity recovery effect. In order to decrease the formation damage of extraneous operating fluid，a workover fluid which could protect formation was developed. Boundery film washing agent，viscosity reducer，anticrustator and clean up additive used to prepare prepad fluid was optimized by laboratory experiment，and the viscosity increasing property of temporary plugging fluid（TPF）and the plugging performance of the TPF for core and permeability recovery of the core after gel breaking were evaluated. The experiment results showed that the displacement efficiency and viscosity reduction rate of prepad fluid，composed of 15% boundery film washing agent GXXJ + 1.5% viscosity reducer JN-01，0.5% anticrustator ZG-02 and 1% clean up additive ZP-01，was greater than 90% ，respectively，Besides，it could inhibit calcium and magnesium scaling and reduce flowback pressure by 50% . Under the circumstances of 3.5—4 MPa and 60℃，the temporary plugging fluid，composed of 3% oil soluble temporary plugging agent BH-ZD+0.7% viscosity Increaser BH-VIS +3% gel breaker JPC，showed well plugging capacity，moreover，after gel breaking，the permeability recovery rate of core was more than 80% . The workover fluid，composed of prepad fluid and temporary plugging fluid，could prevent organic precipitation and other formation damage. The workover fluid had been applied in S oilfield，after workover，the leakage of operating fluid was low and productivity recover was well.