姬塬油田吴A区水平井冲砂解堵技术应用

Application of sand flushing and plugging removal technology for horizontal wells in Wu A area of Jiyuan oilfield

姬塬油田吴A区长7油藏水平井都是通过加砂压裂进行开采,开采过程中地层出砂问题严重,造成油井低产,为此有必要进行高效的冲砂解堵措施。本文通过优化传统冲砂工艺,设计合理的施工工艺参数,成功解决了吴A区长7油藏水平井的冲砂难题。现场试验结果表明,大排量连泵可以有效冲砂,降低井口注入压力、降低冲砂液密度并提高冲砂液黏度有助于减少地层漏失。吴B1、吴B2、吴B3和吴B4四口水平井冲砂成功率为100%,地层漏失率在20%左右,吴B4井实施冲砂+分段酸化解堵工艺后,日增油量可达到1.69 t,措施有效期为177 d。

The horizontal wells of Chang 7 reservoir in Wu A area of Jiyuan oilfield are exploited by sand fracturing.The problem of formation sand production is serious during the exploitation process,resulting in low oil production.Therefore,it is necessary to take efficient sand flushing and plugging removal measures.By optimizing the traditional sand flushing process and designing reasonable construction process parameters,the sand flushing problem of horizontal well in Chang 7 reservoir in Wu A area is successfully solved.Field test results showed that large displacement through continuous pump could effectively wash sand,reduced wellhead injection pressure,reduced sand washing fluid density and improved sand washing fluid viscosity,which were helpful to reduce formation leakage.The sand flushing success rate of four horizontal wells Wu B1,Wu B2,Wu B3 and Wu B4 was 100%,and the formation leakage rate was about 20%.After the sand flushing and staged acidizing plugging removal process were implemented in Wu B4 well,the daily oil production increase could reach 1.69 t,and the effective period of the measures was 177 d.