深层含硫气井井下解堵措施研究及应用

Study and Application of Ultra-deep Sulfur Gas Well Plugging Removal Measures

安岳气田高石梯区块灯四气藏为高温中含硫气藏,钻完井及酸化施工过程中部分入井化学添加剂在地层高温高压条件下生成长链脂肪酸、饱和烷烃等有机物。气井生产过程中这些黏性物质与酸化后地层岩石的反应残余物等无机物胶结,并在井筒形成大量堵塞物,造成油管堵塞、井下绳索作业遇阻(卡)等异常情况。文章从堵塞物成分分析入手,结合气藏特征和气井生产特点,分析堵塞物成因及主控因素,选择化学解堵为主要的井下解堵工艺,并评价优选出两种高性能解堵剂。通过总结摸索,形成井筒清洗—开井排液—绳索作业一体化施工程序,解堵剂用量较以往下降3~5倍,并在高石梯区块成功实施井下解堵作业8井次,提质增效成效显著。对类似气藏开发过程中的井下堵塞和解堵具有借鉴意义。

Gaoshiti Deng-4 block located in Anyue gas field is a gas reservoir with middle sulfur content and high temperature.Some chemical additives injected into well will generate long-chain fatty acid,saturated alkanes and the other organic compounds in high pressure and high temperature layer situation during drilling and completion and acidizing services.During gas well production,these viscous substances are cemented with inorganic substances such as the reaction residues of acidified formation rocks,and a large number of blockages are formed in the wellbore,resulting in abnormal conditions such as tubing blockage and sticking in downhole wireline operations.This paper analyzes the reasons for plugging and main control elements,based on the plugging material components and combined with gas reservoir and gas well production characteristics,chemical plugging removal method is selected as the main procedure,and 2 kinds of high-performance plugging removal agents has been evaluated and selected.Through summary and exploration,the integrated construction procedure of wellbore cleaning-well opening and flowback fluid-wireline operation was formed,and the dosage of plugging removal agent will be decreased by 3-5 times compared with the previous one.In addition,the underground plugging removal operation was successfully carried out for 8 wells in Gaoshiti block,with remarkable results in quality improvement and efficiency improvement,which has a reference significance for the downhole plugging and plugging removal in the development process of the similar gas reservoirs.