Abstract: The present invention discloses a method for lowering an oil pipe in a gas well without well-killing, a soluble bridge plug and a material preparation method thereof, wherein, the method comprises the steps of: lowering a bridge plug in a wellbore such that the bridge plug blocks the wellbore at a predetermined location in the wellbore; injecting water in the wellbore after the pressure in the wellbore has been relieved so as to replace gases in the wellbore; and lowering an oil pipe in the wellbore to the location of the bridge plug. The method for lowering an oil pipe in a gas well without well-killing, the soluble bridge plug and the material preparation method thereof provided in the present invention successfully solve the problem of high cost for lowering an oil pipe under pressure after a fracturing fluid has been injected into the casing.

Abstract: A fiber-reinforced prestressed reinforced concrete sleeper is integrally cast and includes a sleeper body and two rail bearing regions. A rail clamping base is arranged on a surface of the each rail bearing region. The two rail bearing regions are located under rails on both sides of the sleeper and the two rail bearing regions are located above the sleeper body. A reinforcing fiber is mixed into the two rail bearing regions only, and a reinforcing rib is arranged in the sleeper body. The reinforcing fiber is concentrated in a main stress region under the surface of the rail bearing regions. The reinforcing fiber arranged in a region with a large stress is more than the reinforcing fiber arranged in a region with a small stress.

Abstract: A fiber-reinforced prestressed reinforced concrete sleeper is integrally cast and includes a sleeper body and two rail bearing regions. A rail clamping base is arranged on a surface of the each rail bearing region. The two rail bearing regions are located under rails on both sides of the sleeper and the two rail bearing regions are located above the sleeper body. A reinforcing fiber is mixed into the two rail bearing regions only, and a reinforcing rib is arranged in the sleeper body. The reinforcing fiber is concentrated in a main stress region under the surface of the rail bearing regions. The reinforcing fiber arranged in a region with a large stress is more than the reinforcing fiber arranged in a region with a small stress.

Abstract: The present invention discloses a method for lowering an oil pipe in a gas well without well-killing, a soluble bridge plug and a material preparation method thereof, wherein, the method comprises the steps of: lowering a bridge plug in a wellbore such that the bridge plug blocks the wellbore at a predetermined location in the wellbore; injecting water in the wellbore after the pressure in the wellbore has been relieved so as to replace gases in the wellbore; and lowering an oil pipe in the wellbore to the location of the bridge plug. The method for lowering an oil pipe in a gas well without well-killing, the soluble bridge plug and the material preparation method thereof provided in the present invention successfully solve the problem of high cost for lowering an oil pipe under pressure after a fracturing fluid has been injected into the casing.

Abstract: The present invention provides a fissured substrata water pumping apparatus and methods thereof. The fissured substrata water pumping apparatus includes a water pumping pipe inserted into a drilled hole under a roadway floor; one or more unidirectional water-blocking plates configured inside the water pumping pipe; a servo pump; and an annular drainage siphon having a first end connected to an upper end of the water pumping pipe, and a second end connected to an inlet end of the servo pump through a valve.

Abstract: An anchoring and anti-clogging drill rod for a coal mine floor and methods thereof are provided. The anchoring and anti-clogging drill rod includes a hollow drill pipe and a hollow sleeve configured inside the hollow drill pipe. A front joint is configured at a front end of the hollow drill pipe. A back joint is configured at a back end of the hollow drill pipe. The hollow sleeve is wound with a spiral connection line in a direction opposite to a rotation direction of the anchoring and anti-clogging drill rod during drilling. A spiral-shaped space is formed between the spiral connection line and an inner chamber of the hollow drill pipe.

Abstract: The present invention provides a fissured substrata water pumping apparatus and methods thereof. The fissured substrata water pumping apparatus includes a water pumping pipe inserted into a drilled hole under a roadway floor; one or more unidirectional water-blocking plates configured inside the water pumping pipe; a servo pump; and an annular drainage siphon having a first end connected to an upper end of the water pumping pipe, and a second end connected to an inlet end of the servo pump through a valve.