海上油田注聚过程中的井间窜流与防窜对策

Inter-well flow during polymer injection for offshore oilfields and preventing methods

为了确保海上油田采用"一泵多井"注聚工艺时的注聚质量,对海上油田注聚流程进行了较为系统的矿场监测和试验。在矿场调整试验中证实了泵井压力与井间压力不协调引起井间窜流的机理,给出了"一泵多井"时的窜流判断方法以及窜流方向与共泵井数之间的关系,最后,根据井间窜流发生机理,给出了有针对性的防窜对策。矿场试验表明:注聚过程存在井间窜流现象;基于海上油田"一泵多井"的注聚工艺流程特点,井间窜流的出现将导致注聚井的注入方式由连续注聚转变为水聚交替,将严重影响注聚质量。建议共泵井数不宜超过3口,在进行工艺设计时需要进行泵井组合优化。

Systematic monitoring and testing are conducted for the process of polymer injection for offshore oilfields, in order to ensure the quality of ＂one-pump-multi-well＂ polymer injection for offshore oilfields. Through the adjustment test, the mechanism of inter-well flow caused by the inconsistency between ＂well pump pressure＂ and ＂inter-well pressure＂ is proved. A method for judgment of inter-well flow and the correlation between the direction of inter-well flow and the number of one-pump wells are presented in this paper. According to the mechanism of ＂inter-well flow＂, measures for preventing inter-well flow are given. Field test shows that ＂inter-well flow＂ occurs during polymer injection. On the basis of the characteristics of polymer injection technology for ＂one-pump-multi-well＂ in offshore oilfields, the occurrence of ＂inter-well flow＂ may lead to the change of injection ways of polymer injection wells, i.e. the change from ＂continuous polymer injection＂ into ＂water alternating polymer injection＂. As a result, the polymer injection quality may be affected seriously. It is suggested that the number of one-pump wells be less than three. It is necessary to optimize the pump-well combination while conducting technology design.