卫城油田"酸化堵水"调剖工艺技术

针对卫城油田高压低渗透、高温、高矿化度的油藏特点,开展了一种以"酸化-堵水"相结合的调整注水井吸水剖面新工艺技术试验。它通过前酸后堵、前堵后酸或添加沉淀反应液的酸化技术,将堵塞位置推离井眼附近,实现既能注水又能解决高压井的注入水去进或微裂缝的目的,从而调整注水并吸水剖面结构,扩大水驱波及面积,改善水驱开发效果。施工的8口水井时应油井21口,见效17口,见效率80.9%,井组平均日增油2.3t,降水8.6m3,截至1997年12月底,累计增油2894t,降水1254m3,有效期158d。

ACIDIZING-WATER SHUTOFF"PROFILE CONTROL TEST IN WEICHENG OIL FIELD

A new technology test of controlling water absorption profile in water injec-tion well by combining 'acidizing-water shutoff" together was conducted in Weicheng oil fleld aiming at the reservoir characterlstics of high pressure, low permeability, high tempera-ture and high salinity of this field. By means of acidizing technology of acidizing before water shutoff, water shutoff before acidzing or adding precipitation reaction fluid, the plugging po-sition was removed away from nearby well bore, thus, not only water was inJected into for-mation, but also the problems of micro -fractures and fingering of injection water in high pressure well were settled. By doing so, water absorption profile of the water injection well was adjusted, water sweeping area was enlarged, water flooding development effect was im-proved. Among the 21 producers controlled by the 8 treated injectors, 17 producers became effective, the effective rate was 80. 9%. The average daily incremental oil of the well group was 2. 3 t, water decreased by 8. 6m' every day. By the end of December 1997, the accumu-lated lncremental oil was 2894 t, water decreased by 1254m3 in total, the effective days were 158.