接箍座落式井下节流装置

Collar seating type downhole throttling device

针对苏里格气田常用的卡瓦式井下节流器打捞解卡工艺复杂、部分卡瓦咬死油管导致打捞成功率低的问题,通过研究现有井下工具锚定方式及结构特点,设计了接箍座落式井下节流装置。该装置采用无齿卡爪配合油管接箍间隙实现坐封,打捞时无需专门解卡,具有易解卡、不咬死油管、防下滑等优点。通过有限元分析方法,模拟了井筒实际压力和温度条件,并对装置核心部件卡爪锚定机构进行了应力分析和优化设计。在室内实验成功的基础上,该井下节流装置现场应用38口井,生产一段时间后打捞10口井,坐封稳定、密封可靠、打捞方便,成功率达100%。

The slip-type downhole choke which is commonly used in the Sulige Gas Field is complex in fishing and unfreezing technologies and its success rate of fishing is low for the tubing is bitten by some slips. In this regard, the anchoring mode and structural characteristics of existing downhole tools were investigated and a collar seating type downhole throttling device was designed. By virtue of this new device, the setting is realized using adont claw, combined with tubing-collar clearance, and no specific unfreezing is needed in the process of fishing. And it is advantageous with easy unfreezing, free tubing and downslide prevention. Then, the actual borehole pressure and temperature were simulated by means of the finite element analysis method. In addition, stress analysis and design optimization were conducted on the core component of the collar seating type downhole throttling device, i.e., the claw anchoring mechanism. After the success of laboratory experiments, this kind of downhole throttling device was applied on site in 38 wells. Fishing was conducted in 10 wells after production was carried out for a while. It is shown that collar seating type downhole throttling device provides stable setting, reliable sealing and convenient fishing with the success rate of 100%.