Mining method for low permeability reservoir of shale gas and the like

Abstract

The invention provides a mining method for low permeability reservoir of shale gas and the like. The mining method comprises the steps of arranging a main shaft, forming at least three auxiliary holes in the storage layer on the periphery of the main shaft, performing storage layer transformation in the holes mainly through energizing blasting so as to increase cracks and enable the cracks to be communicated with the main shaft; and maintaining the holes and sealing the shaft after the holes are transformed, and performing production mining and drainage through the main shaft. Completion methods of the holes can be classified into a branch locating shaft, a cluster wall or combination of the branch locating shaft and the cluster wall. The distance between the holes and between the holes and the main shaft is 10-2000m, the diameters of the holes are not smaller than 150mm. The mining method for the low permeability reservoir of the shale gas and the like solves the technical problems that a horizontal shaft must be drilled, multistage fracturing and the like must be performed when the low permeability reservoir is developed, a novel shaft type which is simple to construct, small in occupied area and wide in application range, has low requirements for technical equipment and does not depend on a water source and the novel method are applied to industrialization of low permeability oil gas.

Description

technical field [0001] The invention belongs to oil and gas reservoir exploitation technology, and relates to a low-permeability oil and gas reservoir exploitation method. Background technique [0002] Energy is the basis of social and economic development, and is the factor of human life and production. The impact of the nuclear power crisis after the earthquake in Japan has further intensified the global emphasis on and dependence on traditional energy. A notable feature of shale gas and other low-permeability oil and gas reservoirs is low permeability, which makes it difficult to use conventional oil and gas wells for production and drainage. China's low-permeability oil and gas resources are very rich, and the area of ​​shale gas resources alone reaches 3 million square kilometers, which has huge resource potential and prospects for exploration and development. Their successful development will not only improve China's energy structure, ease the demand pressure of oil ...

AI Technical Summary

Problems solved by technology

In addition to some disadvantages in energy outsourcing, this method also has the problem of the adaptability of foreign existing technologies to China's complex geological conditions.

Studies have shown that the geological background for the formation of shale gas in China is more complex than that in North America, with multi-stage tectonic movements superimposed and reformed, reservoirs buried deeper, and faults and folds far more developed than those in the United States. Whether the existing technologies in the United States can be applied to China remains to be seen. Verification, China's currently completed exploratory wells also show poor gas yield

[0008] Chinese patent 201110064277.7 discloses a method and device for increasing the recovery rate of shale gas by means of explosion. Due to the limitation of protected wellbore and equipment, the amount of charge cannot be too large, so the range of impact of blasting is limited and the usable reserves are less

Images