井下多功能注水工具的研究

Study of Underground Multi-function Water Injection Tools

葡萄花油田外围低渗透油藏由于渗透率低、储层发育差、层间矛盾大等原因,导致不少注水井注不进水,返吐出油。应用常规分层注水管柱,因地层返吐的油通过桥式偏心配水器的水嘴及管柱最底端的球座进入油管内部,导致注水井分层测试时仪器下井困难甚至掉卡,研发了井下多功能注水工具。该工具由单流导压配水器及免投捞可洗井压力开关两部分组成,前者使套管内的液体无法由配水器出水孔进入油管内部,后者能保证停注时套管内液体无法由管柱底部进入油管,二者结合能够有效限制油套环空内油泥及杂质进入油管,始终保持油管内清洁,从而提高测试仪器下井成功率及分层测试效率,提高分层注水效果。现场应用该工具施工51口井,投捞测试仪器一次起下成功率达到98.0%,累计减少测试前投捞堵塞器383井次,平均单井有效期869d。

The water can ’ t be injected and oil was produced in a lot of water injection wells because of low permeability,poor development of reservoir and great interlayer contradiction in the low permeability reser-voirs in the periphery of Putaohua Oilfield.General layering injection string was difficult for running or even being locked when testing because the oil from the formation flows into oil pipe through water nozzle of the bridge eccentric water distributor and ball seat at the bottom of the string.Underground multi-function water injection tool was developed to solve these problems.It is composed of single flow pressure water regulator and free throw well flushing pressure switch.The former is designed for preventing the liquid in casing from the outlet of regulator into oil pipe,and the later is designed for preventing the liquid in casing from the bottom of the string into oil pipe.The combination of the two sets of tools can keep the oil pipe clean by preventing oily sludge and impurity in the oil pipe-casing annulus into the oil pipe,and improve the success rate of the well running and testing efficiency and layering injection effect.This tool was applied in 51 wells of the field,success rate at the first running of the throw testing instrument is up to 98.0%,running and pulling of the plug was reduced for 383 well-times before testing cumulatively,and average validity for single well is 869d.