贵州岩溶地区煤层气钻井关键技术

Key Coalbed Methane Drilling Technology in Guizhou Karst Area

摘要:

贵州省煤层气资源十分丰富，在前期的煤层气勘探开发过程中，出现了诸多钻井难点，一开钻进过程中容易遇碰到溶洞,存在井漏和井口失返现象；地层倾角大，可钻性差。二开钻井机械钻速低；煤层多而薄，机械强度低，岩心采取率低。这些钻井难点严重制约了贵州岩溶地区煤层气勘探和开发的进程。本文通过分析贵州岩溶地区地层特征和钻井难点，并通过多年的工程实践，总结出了一套适合贵州岩溶地区的煤层气钻井关键技术，包括一开空气钻井技术、二开快速钻井技术和绳索取心钻进技术等。本文的研究成果不仅适合贵州岩溶地区煤层气勘探和开发，对其他地区的煤层气勘探和开发也有借鉴意义。

Abstract:

Coalbed methane resource is very abundant in Guizhou Province. In the early stage of exploration and development, there are many drilling difficulties, karst cave were often encountered in the first section drilling with leakage, circulation lost, large dip angle and poor drillability; in the second section drilling, low ROP and thin coal seams led to low core recovery rate, these difficulties seriously restricted the exploration and development process of coalbed methane in Guizhou karst area. By the analysis on the formation characteristics and drilling difficulties of Guizhou karst area and based on years’ engineering practice, this paper summarizes a set of key technologies suitable for coalbed methane drilling in Guizhou karst area, including air drilling technology in the first drilling section, fast drilling technology in the second drilling section and wire-line coring technology. The research results can be suitable not only for the coalbed methane exploration and development in Guizhou karst area, but also can be reference for the coalbed methane exploration and development in other areas.