海上油田分层注水反洗井技术研究与应用

Research and application of integrated technology for zonal injection and backwashing in offshore oilfields

为了解决海上油田分层注水井管柱结垢、腐蚀,油层污染、堵塞,注水压力上升等问题,结合海上油田注水井地层条件、完井方式和生产管柱型式等特点,研究设计了提升式、液控膨胀式、插入密封式等3种反洗井管柱,进而提出了3种海上油田分层注水反洗井技术。阐述了提升式、液控膨胀式、插入密封式等3种反洗井管柱的设计原则、设计关键点和管柱组成,以及3种海上油田分层注水反洗井技术的技术原理、技术参数和使用条件。现场应用表明,本文提出的3种反洗井注水管柱技术能够在不动注水管柱条件下实施反洗井作业,达到维护注水井井筒、清洗注水管柱、提高分层注水效果的目的,目前已在绥中、渤西、渤中、辽东、蓬莱等作业区取得成功应用,具有较好的推广应用价值。

To solve the problems occurring in zonal injection wells offshore,such as scaling,corrosion,reservoir damage,blocking and injection pressure increase,three types of backwashing strings for the lifting mode,hydraulically-controlled expansion mode and insert sealing mode were studied and designed in light of the characteristics of the relevant formations,completion method and type of production string etc. of the offshore injection wells. And based on that,three ways for zonal injection and backwashing were put forward. This paper elaborated the design principles,design features and compositions of the tree types of backwashing strings,as well as the technical priciples,parameters and application conditions of the three ways of the integrated technology for zonal injection and backwashing. Field applications indicated that with the new technology backwashing could be conducted without running in or pulling out the injection string. With the technology we can also maintain the injection wellbore,wash injection string,and enhance zonal injection effects. The new technology has been successfully used in Suizhong,Boxi,Bozhong,Liaodong,Penglai,and other blocks with good prospective of further dissemination.