基于自乳化保护的水平井选择性堵水方法及其在南海东部P油田的应用

Selective water plugging technology for horizontal wells based on self-emulsification protection and application in P oilfield in the eastern South China Sea

针对海上油田水平井控水成本高,化学堵水成功率低,部分油井堵水作业后产液量大幅降低等问题,提出了一种基于自乳化保护的水平井化学堵水方法。通过自乳化保护液的注入对含油储层进行保护,避免后续堵剂污染含油储层,实现选择性堵水。提出现场注入工艺参数及堵水药剂性能设计原则,实现水平井不找水堵水。与传统化学堵水技术相比,该技术无需找水作业、现场施工工艺简单,通过药剂性能及施工参数控制,堵水体系可定向封堵出水层位,有效提高化学堵水的成功率并降低作业成本。研究表明,基于自乳化保护的堵水技术体系性能与施工工艺参数设计可实现选择性不找水堵水,保护液体系可对水平井含油储层形成有效保护,避免堵剂对含油储层的污染。室内实验表明堵水后水驱采收率提高29.58个百分点。研究结果应用于南海P油田,控水稳油效果良好。

Aiming at the problems such as high cost of water control,low success rate of chemical water plugging,and reduction of liquid production after water plugging in some oil wells,a method of chemical water plugging in horizontal wells based on self-emulsification protection is proposed.The oil-bearing reservoir is protected by injection of self-emulsification protection liquid to avoid subsequent plugging agent pollution.In this paper,the field injection process parameters and the design principle of water plugging agent performance are put forward to realize water plugging in horizontal wells without water finding.Compared with the conventional chemical water plugging technology,the technology does not need water finding and has a simple construction process.Through the control of chemical properties and construction parameters,the water plugging system can block the water outlet layers,effectively improve the success rate of chemical water plugging and reduce the operating cost.The research shows that the performance of the water plugging agent based on self-emulsification protection and the design of construction process parameters can realize the selective water plugging without water finding,and the protection liquid can effectively protect the oil-bearing reservoir of horizontal wells and avoid the pollution of the plugging agent to the oil-bearing reservoir.The laboratory experiment shows that the water flooding recovery rate increases by 29.58%after water plugging.The research results have been applied to the P oilfield in the South China Sea with good water control and oil stabilization effects.