南海东部油田同井采油分层自均衡注入技术的应用

Application of self balancing injection technology for same well oil recovery in the eastern South China Sea oilfield

南海东部油田纵向上发育多套边底水油藏,经过多年开发,油层的地层能量出现亏损,导致产能开始出现较快下降,精细分层注水是对地层进行能量补充有效手段之一。同井采油分层注水技术设计有许多优势,但是受管柱配套管工艺复杂,流量测试及调配复杂多种因素影响,给施工增加了难度和风险,需要更加合理的设计和优化配套工具,保障顺利实施。自均衡注水技术在防砂筛管上安装自均衡注入阀,通过合理的设计,实现在整个注水周期内按照配比进行注水量的自适应调节,保障各注水目标层基本以油藏设计注入量进行精细分层注水,有效地对地层能量进行了补充。自均衡注入技术在注水井段采用了单管柱结构,简化了管柱工艺,降低了施工难度和风险,保障了同井采油分层注水技术的现场顺利实施。

Multiple sets of edge and bottom water reservoirs are vertically developed in the eastern oilfields of the South China Sea.After years of development,the formation pressure of the reservoirs has been depleted,leading to a rapid decline in production capacity.Fine layered water injection is one of the effective methods for supplementing energy in the formation.The design of stratified water injection technology for oil recovery in the same well has many advantages,but it is affected by various factors such as the complex process of supporting the pipe string,flow testing,and allocation,which increases the difficulty and risk of construction.Therefore,more reasonable design and optimization of supporting tools are needed to ensure smooth implementation.Based on the use of a combination of sand control screen pipes and packers to achieve the isolation of the target layer,through reasonable design,achieve adaptive adjustment of the water injection volume according to the ratio throughout the entire water injection cycle,ensuring that each water injection target layer is finely layered with the designed injection volume of the reservoir.Effectively replenished the energy of the formation.The FloFuse injection technology adopts a single string structure in the water injection well section,simplifying the string process,reducing construction difficulty and risks,and ensuring the smooth implementation of the same well oil production and layered water injection technology on site.