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过去的二十年间,在定向钻井系统方面的显著进步导致了一种技术的成熟。这种技术能够为采煤业提供各种各样的甲烷抽放选择,并有助于在开采前更好地鉴定和了解地质与开采条件。70年代发展的配有单点照相测量系统和钻孔间距稳定器的井下钻孔控制技术已被90年代开发的孔底测量系统所取代,该系统配有钻孔测量仪器、大推力钻孔设备、强力孔底马达和高强度钻机套管。这些系统能够有效地实施水力压裂,以增加煤层气抽放时在煤层透气性差的情况下的井孔连通性,并能够在长壁开采前对顶板整体卸压。 本文介绍定向钻井系统的最新发展,并回顾该技术的多种用途,其中包括煤层内煤层气抽放、采空区煤层气抽放、商业性煤层气开采、废弃的井下采区探测、开采前方煤层间断性的鉴别,以及煤、顶底板特性的确定和卸压等。总部设在美国的REI公司所属的REI钻孔公司和设在新南威尔士州澳大利亚河谷长壁钻孔分公司采用了定向钻孔技术。这些公司采用这种新技术每年钻孔米数高达130,000m。
Over the past two decades, significant advances in directional drilling systems have led to the maturation of a technology. This technology provides a wide range of methane drainage options for the coal mining industry and helps to better identify and understand geology and mining conditions prior to mining. Downhole drilling control technology developed in the 1970s with a single-point photogrammetric system and borehole spacing stabilizer has been replaced by a hole-bottom measurement system developed in the 90’s that is equipped with borehole measurement instruments, high-thrust drilling equipment , Powerful bottom hole motor and high-strength drilling rig casing. These systems can effectively implement hydraulic fracturing to increase wellbore connectivity with poor permeability of coal seams during CBM drainage and to allow for overall relief of the roof before longwall mining. This article presents the latest developments in directional drilling systems and reviews the versatility of the technology, including CBM drainage in coal seams, CBM drainage in goafs, commercial CBM exploration, abandoned underground mining exploration, front mining Coal seam intermittent identification, as well as coal, roof and floor characteristics of the determination and pressure relief. REI drilling company, headquartered in the United States, and directional drilling at the Australian Valley Longwall Drilling Company, New South Wales, employ directional drilling technology. These companies use this new technology to drill holes up to 130,000 m per year.