Being controlled by the gas content of the reservoir, the productivity of CBM well is also mainly determined by its engineering quality and the physical property of the reservoir. In Dafosi mine field, 22 vertical wel...Being controlled by the gas content of the reservoir, the productivity of CBM well is also mainly determined by its engineering quality and the physical property of the reservoir. In Dafosi mine field, 22 vertical wells from the “26 + 1” CBM wells project that was implemented since 2014 showed great difference in productivity after fracturing construction. With the consistent geological condition of coal reservoirs, fracturing construction parameters are suggested as the priority factor that controlling the well productivity. In this study, being combined with historical production and geological data, an optimized designation of fracturing construction parameters was established based on systematically comparative analysis of construction parameters such as discharge, the total volume of fracturing fluid, the quality of sand, sand ratio, which provides engineering basis for further fracturing construction of CBM wells.展开更多
Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken...Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.展开更多
文摘Being controlled by the gas content of the reservoir, the productivity of CBM well is also mainly determined by its engineering quality and the physical property of the reservoir. In Dafosi mine field, 22 vertical wells from the “26 + 1” CBM wells project that was implemented since 2014 showed great difference in productivity after fracturing construction. With the consistent geological condition of coal reservoirs, fracturing construction parameters are suggested as the priority factor that controlling the well productivity. In this study, being combined with historical production and geological data, an optimized designation of fracturing construction parameters was established based on systematically comparative analysis of construction parameters such as discharge, the total volume of fracturing fluid, the quality of sand, sand ratio, which provides engineering basis for further fracturing construction of CBM wells.
文摘Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.
