新街台格庙矿区煤层气参数井钻井关键技术

Key technology for drilling CBM parameter wells in Taigemiao mining area of Xinjie

针对鄂尔多斯盆地东部台格庙勘查区煤层气勘探中,部署和钻探的6口煤层气参数井,经常出现井漏、卡钻、井垮、井斜超标、钻头堵死等问题,在钻探期间采用合理的钻孔结构和钻具组合、优选钻井液性能和钻井参数,引用成熟的绳索取心钻进技术,保证取心效果;完井后采用注入/压降试井技术,获取台格庙目标煤层含气性及储层数据,评价煤层气产能。结果表明:参数井取心收获率为93%~98%,机械钻速1.63~2.55 m/h,井斜控制在2.69°~3.22°,地层压力系数0.93,煤层渗透率1.16×10–3μm^2,降低煤层气钻井和测试成本,为今后相似地区的煤层气钻探施工和测试提供借鉴和参考作用。

In order to strengthen the protection of coal resources in Taigemiao mining area of Xiejin and realize the green exploration,a total of 6 coalbed methane parameter wells were deployed and drilled.Due to the coal quality of the coal-bearing strata,the development of fractures and joints,the low permeability,and the strong adsorption capacity,problems such as fluid leakage,stucking,borehole collapse,hole deviation exceeding the standard,and drill bit blocking are often encountered.During the drilling,reasonable drilling structure and drilling tool combination,preferred drilling fluid performance and drilling parameters are adopted,and the mature rope core drilling technology is adopted to ensure the coring effect;after completion,the injection pressure drop test technology was used to obtain the grid.The gas and reservoir data of the target coal seam in the area were assessed to evaluate the production capacity of the coalbed methane.The results show that the harvest rate of the parameters was 93%-98%,the mechanical drilling rate was 1.63-2.55 m/h,the well inclination was 2.69°-3.22°,the formation pressure coefficient was 0.93,the coal seam permeability was 1.16×10–3μm2,and the better drilling was obtained.And the test results provide reference for CBM drilling construction and testing in similar areas in the future.