某高压凝析气田集输管线水合物冻堵防治

Controlling Freezing and Ice Blockage Induced by Hydrate in Transportation Pipelines: Example from a Gas Condensate Field with High Pressure

针对某高压凝析气田的气井大修重新开井后集输管线发生水合物冻堵的现状,简要介绍了气田井口集输流程和集输管线发生水合物冻堵的过程,分析了集输管线水合物的冻堵条件和影响因素。同时对常用的抑制水合物方法如提高产量法、加热法、加注甲醇法、反吹解堵法,结合高压凝析气井大修后的实际情况进行了适用性分析和效果评价,得出了一些结论认识,如针对有些单井离集气站较远的情况,可以使用多个水套炉多次加热;对节流效应明显、冻堵严重的单井除采用电伴热加热外,还可对其加注甲醇或高矿化度盐水来抑制水合物的形成。

In a gas condensate field with high pressure, both freezing and ice blockage induced by hydrate easily happen in some transportation pipelines after overhaul and reopen of gas wells. This paper illustrates not only wellbore transportation but also freezing and ice blockage processes, and analyzes some conditions and affecting factors of freezing and ice blockage. Moreover,some common-used methods to inhibit hydrate are presented, such as production- increasing, heating, methanol- injecting, and antiblowing blockage removal ones. For these methods, the applicability and effect are analyzed and evaluated. At last, some conclusions are obtained, including(1) to use many water jacket furnaces and to heat many times for gas wells far away from a gas-gathering station,and(2) for gas wells with obvious throttling effect or severe ice blockage, to inject methanol or brine with high salinity in order to inhibit hydrate except electric heating.