火山监测流体观测井复杂落物打捞修复技术

Fishing and remediation technology for complex falling objects in volcanic monitoring fluid observation well

摘要:

某火山监测站流体观测井因仪器卡死及前期打捞失败，导致井内遗留钻杆、线缆等多种复杂落物，且施工受高海拔景区场地与环保严格限制。针对此复杂井况，采用井下电视精准探查事故头，综合运用“捞、反、磨、套铣”等工艺进行修复。施工中采用外力辅助增扭，使用反丝公锥造扣并倒扣，成功反出事故钻具；定制带绞线筒的套铣工具，并创新改进（内壁焊钢筋钩）以清除缠绕线缆与打捞钻具；最终采用公接手对接打捞及外钩打捞清理残余线缆。同时，配制高黏度冲洗液携屑，并构建闭环系统实现冲洗液零排放。结果成功捞出井内全部落物，累计捞出事故钻杆总长173.44 m，并捞出全部线缆、仪器及打捞钩，打捞成功率100%，井壁无二次损伤，完全恢复观测井功能，挽回经济损失近200万元。本研究为同类复杂井下落物打捞修复提供了可借鉴的技术思路与实践经验。

Abstract:

Due to instrument sticking and a previous failed fishing operation， a fluid observation well at a volcanic monitoring station was left with various complex fish， such as drill pipes and cables. Furthermore， the operation was strictly constrained by the high-altitude scenic location and environmental protection requirements. To address these complex well conditions， a downhole television system was used to accurately locate the top of the fish， and a combination of techniques-fishing， back-off， milling， and washover milling-was applied for well remediation. During the operation， external force was applied to increase torque， and a left-hand tapered tap was used for thread making and back-off， successfully backing off the stuck drill string. A customized washover tool with a wire-reel barrel was developed and innovatively modified （by welding steel bar hooks on its inner wall） to clear entangled cables and assist in fishing the drill tools. Finally， pin joint connection fishing and external hook fishing were employed to recover the remaining cables. Meanwhile， a high-viscosity drilling fluid was formulated for cuttings removal， and a closed-loop system was established to achieve zero discharge of drilling mud. As a result， all downhole fish were successfully retrieved， including a total length of 173.44 m of stuck drill pipes， along with all cables， instruments， and fishing hooks， achieving a 100% fishing success rate. The wellbore sustained no secondary damage， the function of the observation well was fully restored， and economic losses of nearly 2 million RMB were saved. This study provides referable technical approaches and practical experience for the fishing and remediation of complex fish in similar troubled wells.