Screen guard hole Borehole ensure effectiveness, improve high gas pumping rate

Drilling screen for soft, easily deformed broken ground into the hole after drilling, collapse, resulting in the use of drilling rate, short life and other issues under the rapid development of a protective screen hole, drilled adhere unimpeded passage retaining hole skills and supporting equipment. Not to mention into the hole after drilling, starting with the suspension retaining hole into the pipe interior equipment Chase hole next to the hole bottom screen, and then proposed drill the retaining holes left on the screen holes to form lasting extraction circuit arriving retaining hole intentions.
Skills principle
Coal mine retaining hole screens usually are functional screens, while adhering to the drilled tunnel intelligible together with the gas drainage, checking discharge of formation water, plugging grouting save or other functions, without the need for secondary drilling, which in diameter scale without close coordination with the hole wall, which can be chosen after the drill pipe under the screen, and then proposed drill pipe. Detailed flow shown in Figure 1: ① construction planning to drill hole depth; ② screen from the drill down into the interior, and suspended in the wall of the hole; ③ proposed drilling, screen left in the hole.
Skills Features
It uses a wide blade spiral drill slagging good effect, as high porosity, air drilling does not affect the gas desorption is conducive to gas drainage through the drill string through holes at the screen, ensuring depth. Screen guard hole Borehole ensure effectiveness, improve high gas pumping rate.
Through theoretical analysis and practice indicated, "first down tube, Timothy drill" screen after drilling holes skills due to the deformation process, resulting in the collapse of the screen under the low down is not in place, the difficult problem of the down tube, complete Bored "playing deep, and in the end tubes, pumping in place," the gas management philosophy, improve the rate at drilling into the screen, saving time into the next, reducing the labor intensity, in the coal mine gas drainage hole, grouting holes and other screen pipe, grouting pipe construction process with outstanding results.