Research on hole protection technology of screen pipe for hydraulic transportation and automatic butt joint in high position directional borehole
ZHANG Jinbao
保障高位定向长钻孔在工作面回采过程中的稳定抽采是实现“以孔代巷”的前提,而采用筛管完孔是维持钻孔稳定的有效护孔措施。为了实现高位定向长钻孔全孔段筛管护孔的工程应用,开发了钻孔内水力输送分组筛管自主对接完孔工艺技术,配套研制了ø95 mm筛管悬挂装置、ø95 mm玻璃钢筛管、ø100 mm封堵短节、ø140 mm钻头通水堵头以及ø95 mm分组筛管对接装置,并在皖北矿区两个煤矿的不同工作面顶板高位钻孔进行了水力输送分组筛管完孔现场试验。试验结果表明:玻璃钢筛管质量轻推送阻力小,可在倾角17°~26°的钻孔内人工连接长100 mø95 mm玻璃钢分组筛管,分组筛管输送过程中水压为1.0~1.5 MPa,输送到位时水压降为0.5 MPa以下,在泵量200~390 L/min下,分组筛管水力平均输送速度可达150~260 m/min,试验期间分组筛管输送到位时泵压变化明显,前后两组筛管对接可靠,可有效实现到位报信,成功实现ø153 mm高位定向钻孔内ø95 mm筛管的全孔段护孔,2个钻孔的筛管水力输送试验深度分别达到501、522 m,工作面回采120 d累计抽采瓦斯纯量分别为139 945、176 139 m3。钻孔内水力输送对接筛管护孔技术为高位定向长钻孔全孔段大直径筛管护孔提供了可实现的技术解决方案,有助于保障高位定向长钻孔的瓦斯抽采效果,为煤矿井下“以孔代巷”的瓦斯治理模式革新提供技术支撑。
Ensuring the stable extraction of high position directional long boreholes in the mining process of working face is the premise of realizing ' replacing the roadway with the boreholes', and the use of screen pipe completion is an effective hole protection measure to maintain the stability of boreholes. In order to realize the engineering application of full-hole segment screen pipe protection in high position directional borehole, the technology of automatic butt joint technology of grouping screen pipe for hydraulic transportation in the borehole has been developed, and the ø95 mm screen pipe Hanging unit, ø95 mm fiberglass screen pipe, ø100 mm water flow blocking short section, ø140 mm drilling bit plug with passable water and ø95 mm grouping screen pipe connecting device have been developed, In addition, the field test of hydraulic transportation grouping screen pipe hole completion was carried out in the high level boreholes of different working faces in two coal mines in the northern Anhui mining area. The test results show that the weight of the GRP screen pipe is light and the resistance to push is small. The ø95 mm GRP grouping screen pipe with a length of ø100 m can be manually connected in the borehole with an inclination of 17°−26°. The water pressure in the grouping screen pipe transportation process is about 1.0−1.5 MPa, and the water pressure drops below 0.5 MPa when it is transported in place. Under the pump capacity of 200-390 L/min, the average hydraulic transportation speed of the grouping screen pipe can reach 150-260 m/min. The pump pressure changes significantly when the grouping screen tube is transported in place during the test. The front and rear sets of screen pipes are connected reliably, which can effectively realize the message in place, and successfully achieve the full hole protection of ø95 mm screen pipes in the ø153 mm high position directional borehole. The hydraulic transportation test depth of screen pipes in the two boreholes reaches 501 and 522 m respectively and the cumulative pure gas extracted from the two boreholes in 120 d working face mining is 139 945 and 176 139 m3 respectively. The technology of screen pipe for hydraulic transportation and automatic butt joint in the borehole provides an achievable technical solution for the large-diameter screen pipe hole protection in the full-hole section of the high-position directional long borehole, helps to ensure the gas drainage effect of the high-position directional long borehole, and provides technical support for the innovation of the gas control mode of ‘replacing the roadway with the boreholes’ in the coal mine.
high position directional borehole;screen pipe hole completion;hydraulic transportation;replacing roadway with the boreholes;gas drainage
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会