6 results about "Pressure shale" patented technology

The application discloses a high-pressure cut-off valve for shale gas well and belongs to the technical field of high-pressure shale gas exploitation equipment, and mainly solves the problem of overload fracture of a valve core caused by high-pressure unbalanced torque in the prior art. The cut-off valve comprises a valve body, a valve cover and a valve core, the valve body and the valve cover are connected through threads, and the valve core penetrates through the valve cover. The high-pressure cut-off valve can balance the unbalanced torque of high-pressure fluid through the structure of the plugging platform and the gyro-type boss, so that the driving energy consumption of the cut-off valve is reduced and the working efficiency is improved.

According to the gas injection, liquid drainage and gas production method for the shale gas reservoir, by means of multi-layer three-dimensional development of fracture network connectivity, a pressurizing well which is multiple in radiation adjacent wells, good in fracture connectivity and low in pressure and yield in a block is preferably selected as a block low-pressure gas injection well, and gas with good permeability is injected (the injected gas comprises but not limited to N2, CO2 and hydrocarbon gas); the gas enters the horizontal section of the adjacent well by means of connectivity cracks through diffusion and propulsion of the gas, accumulated liquid of the horizontal section of the drainage production well is effectively discharged, the drainage production well is activated to continuously produce gas, and the target of gas injection, liquid drainage and gas production is achieved. By means of an existing shale gas fracturing crack communication system, the advantages of an integral gas reservoir box and the intricate well-well relation, the problem of discharging accumulated liquid in a long horizontal section of low-pressure shale gas is solved, and efficient liquid discharging and gas production of a three-dimensional multi-well horizontal shaft of a shale reservoir are achieved through gas injection displacement. Gas injection huff and puff realizes deep liquid drainage and gas production of a reservoir shaft of the gas injection well, the cumulative yield of the gas well is improved, and the gas reservoir recovery efficiency is improved.

According to the technical scheme, the shaft cleaning regulation and control device and method for drainage and gas recovery of the normal-pressure shale gas well are characterized in that the shaft cleaning regulation and control device comprises a ground, a blowout prevention opening is formed in the top of the ground, and a third manual wheel type valve is fixedly installed on the bottom face of the blowout prevention opening; a small four-way pipe is fixedly installed on the bottom face of the third manual wheel type valve, and a junction box is fixedly installed outside the small four-way pipe. The cleaning assembly is arranged on the bottom face of the small four-way pipe and used for cleaning the interior of a shaft, and the cleaning assembly comprises two fourth manual wheel type valves. The device can deal with blockage of solid-phase particles in the shaft in real time, and when the blockage severity exceeds a certain degree and workover operation needs to be conducted, the device can clean the interior of the shaft before the operation is conducted; temporary plug removal is achieved for the shaft and the screw pump, the function of temporarily coping with complex working conditions is achieved, and effective coping can be provided for actual production problems of normal-pressure shale gas.

The invention relates to a method for calculating the porosity of a normal-pressure shale reservoir based on logging data. The method comprises the following steps: acquiring a rock skeleton logging sound wave value, a rock skeleton density value, a rock skeleton uranium content and a whole-well-periphery transverse wave speed; based on the rock skeleton logging sound wave value, the rock skeleton density value and the rock skeleton uranium content, adopting a regression model to calculate the initial porosity; and calculating a tectonic stress sensitive index based on the principal stress orientation, anisotropic strength and rock mechanical parameters of the tectonic stress field, establishing a dynamic correction model in combination with core-logging joint calibration, and correcting the initial porosity through the dynamic correction model. According to the method, quantification of the anisotropy characteristics of the porosity is achieved, modeling is conducted through multi-source data cooperative processing and stress field dynamic response, the limitation that the influence of a stress field is ignored in porosity calculation of a complex structural area in a traditional method is overcome, the precision and dynamic adaptability of reservoir porosity evaluation are improved, and technical support is provided for efficient development of shale gas reservoirs.

The invention relates to a method for determining the installation distance of a liquid-accumulation-free tubular column of a normal-pressure shale gas well. The problems that an existing liquid-accumulation-free pipe column drainage gas recovery process is not clear in application limit, not clear in process tripping-in position and the like are solved. According to the technical scheme, the method comprises the steps that the liquid accumulation state of a gas well is calculated according to the gas production rate and the water production rate of the gas well, whether a liquid-accumulation-free tubular column needs to be put down or not is judged, if the gas well is subjected to liquid accumulation, the height of a liquid-carrying production section and the number of installed liquid-accumulation-free valves are calculated according to the actual minimum conveying pressure after the liquid-accumulation-free valves are installed, and the installation distance of the liquid-accumulation-free tubular column is determined; according to the method for determining the installation distance of the liquid-accumulation-free tubular column of the normal-pressure shale gas well, the influence of the liquid production capacity and the pressure of the gas well on the tripping-in position of the liquid-accumulation-free tubular column is considered, and the application effect of the liquid-accumulation-free tubular column under the conditions of high liquid yield and low pressure of the normal-pressure shale gas well is improved.

Disclosed is an independent double-negative-pressure shale shaker, and belongs to the technical field of petroleum drilling solid control. The independent double-negative-pressure shale shaker comprises a base, a fluid discharge device, an inclination angle adjustment mechanism, a screening device, an exciting motor and a double-negative-pressure system, wherein the double-negative-pressure system comprises a first negative-pressure system and a second negative-pressure system which are relatively independent; the first negative-pressure system dries drilling fluid of a first screen mesh set close to a material outlet, and the second negative-pressure system increases the treatment capacity of drilling fluid of a second screen mesh set close to the first screen mesh set; and meanwhile, in the deep well section, the second negative-pressure system can be switched to a fluid mist suction state, fluid mist on the screen surface is reduced, the safety is improved, and the pollution of fluid mist is reduced.