天然气钻井气体回收设备的研制

Development of Gas Recovery Equipment on Natural Gas Drilling

天然气钻井过程中,井筒返回至地面的携岩天然气直接放燃,这样既浪费能源又污染环境。为了回收井筒返回至地面的携岩天然气,研究了天然气回收工艺,设计了由一级分离器、二级分离器、缓冲罐和过滤器组成的回收设备。一级分离器起预分离的作用,具有分离效率高、防粘壁、防返混的特点;二级分离器利用导叶式旋分管做分离元件。两级分离器能够除净气体中粒径大于7μm的钻屑颗粒。一级和二级分离器均采用液体输送方式进行连续排料。过滤器选用了外层玻璃纤维滤芯加内层金属纤维滤芯的双层复合滤芯,过滤分离效率可达99.8%以上,能够除净气体中粒径大于5μm的钻屑颗粒,可以保证过滤后的气体达到压缩机的进气要求。该回收设备不仅适用于天然气钻井中的携岩天然气回收,同时适用于其他气体钻井过程中携岩气体的净化和回收。

At present, the burning or exhausting of the well-head gas which carries cuttings in natural gas drilling system caused the environmental pollution and energy waste. In order to recover the wellhead gas in gas drilling system sufficiently, a gas recovery system composed by first separator, second separator, buffer tank and filter was designed. The first order cyclone separator with the characteristic of high efficiency, anti-wall scaling, anti-backmixing was to pre-separate. The secondary separator used the vane guided cyclone tubes. Drilling cuttings bigger than 7μm can be removed by the two stage cyclone separators. Liquid material discharge system was used in the first, second separator to discharging material continuously. The filter adopts double layer composite filter core. The outer layer was glass fiber filter core; the inner layer was metal fiber filter core. The separate efficiency of filter can be maintained above 99.8%. Drilling cuttings bigger than 5 μm can be removed and the purified gas can reach compressors＇ entrance requirements. The system not only can recover natural gas with cuttings in natural gas drilling, but also can clean and recover other drilling gas with cuttings.