Drilling device for low permeability reservoir and drilling method thereof

Abstract

The invention discloses a drilling device for low-permeability reservoirs and a drilling method thereof. The drilling device comprises: a drill bit, on which spray holes and scrapers are arranged; a spray liquid delivery assembly, which includes a drill connected to the drill bit; The jet tube; the guiding mechanism guides the jet liquid delivery assembly and the drill bit to ensure the drilling direction of the drill bit; and the rotation mechanism, which is fixedly connected with the jet liquid delivery assembly and is driven by the delivered high-pressure fluid to drive the drill bit to rotate and break the rock . The drilling device has high operating efficiency, low cost and little environmental pollution.

Description

technical field [0001] The invention relates to the technical field of petroleum exploitation, in particular to a drilling device and a drilling method for improving the flow conductivity of low-permeability reservoirs. Background technique [0002] Compared with traditional oil and gas resources, unconventional resources such as tight oil and gas, shale gas and coalbed methane have low porosity and low permeability, resulting in low single well productivity and low recovery rate, and development faces more challenges. At present, the development of unconventional oil and gas mainly adopts horizontal well drilling technology and horizontal well staged fracturing technology. In addition, complex structure wells and fracturing play an important role in increasing production and efficiency of low-permeability oil and gas reservoirs. [0003] Hydraulic fracturing can increase the contact area between the wellbore and the reservoir, effectively reduce the resistance of oil and g...

AI Technical Summary

Problems solved by technology

However, hydraulic fracturing also has some disadvantages, including: ①During the fracturing process, the fracturing fluid damages the reservoir and easily blocks the oil and gas flow channels

②Hydraulic fracturing construction uses a large amount of water, proppant and chemical additives, which is likely to cause environmental pollution

③Cementing, perforation, well washing and other operations are required before hydraulic fracturing construction, resulting in long construction period

④The fracturing operation requires large-scale fracturing pumps, fracturing vehicles and fracturing fluid, etc., and the operating cost is relatively high

⑤ In heterogeneous reservoirs, the direction of fractures cannot be effectively controlled, resulting in low stimulation effectiveness, and may also cause water and gas layers to be depressurized, leading to early invasion of water and gas

However, during the drilling process of the reservoir, the high-pressure injection hose does not rotate, and only relies on the simple high-speed jet to break the rock. The efficiency is low, the operation time is very long, and the amount of injected liquid is increased, which has a certain impact on the reservoir. pollution

Moreover, this method cannot be used for hard rocks due to jet action, otherwise it is difficult to form pores. Therefore, this method is limited by the characteristics of formation rocks, long operation time and high cost, and it is difficult to effectively promote and apply it.

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