气体钻井地面分离设备液体排料系统的设计研究

Design of Ground Separation Equipment Liquid Discharge System in Gas Drilling

目前,氮气、天然气欠平衡钻井过程中将由井筒返回至地面的气体进行直排放燃,这样既污染了环境,又浪费了能源,增加了钻井成本。为此,设计了一套气体钻井地面分离系统对由井筒返回至地面的气体进行回收,并对分离设备的排料系统进行了设计研究。为充分回收气体并保证连续排料,采用了液体排料的方案。液体输送需要保证排料速度大于临界流速,而临界流速与所输送固体的粒径有关,通过调研和采样分析,掌握了井口钻屑粒度分布范围,确定采用相应的B.C.克诺罗兹公式计算排料临界流速。同时,为了达到带压锁气排料的目的,设计了料罐液位自控方案。最后,针对气体钻井的实际工况对排料系统进行了实例设计,并进行了排料系统携岩排料能力试验,证明所做的设计可行。

At present, the well-head gas carrying cuttings in drilling system are burnt directly, which is polluting environment, wasting energy and increasing cost. The ground separation equipment in gas drilling was designed and the discharge system was investigated. In order to recover gas sufficiently and a- chieve continuous discharge, a liquid material discharge system was used. When the flow rate of material discharge was higher than critical flow rate, liquid had the enough carrying capacity. Critical flow rate was related to the granularity, and the granularity of wellhead drilling cuttings in gas drilling were investigated and analyzed. The Critical flow rate is determined by B. C Knoroz formula. The flow rate of material dis charge was calculated. For the purpose of gas lock, a tank liquid-level control system was designed. Finally the liquid material discharge system was designed and tested; the testing results indicate this design is reliable.