Well drilling device

Abstract

The invention relates to a well drilling device. The well drilling device comprises a main body, a drill bit tire body and cutting teeth, wherein the drill bit tire body is arranged on one end part of the main body; the cutting teeth are formed on the drill bit tire body; the main body is provided with a drilling liquid runner used for inputting drilling liquid; a well-cementing fluid runner isolated from the drilling liquid runner and used for guiding into cementing fluid is also arranged on the main body; an outlet communicated with the well-cementing fluid runner is also formed in the side wall of the main body; the main body is provided with an axial line direction; the well-cementing fluid runner is provided with a first runner extending along the axial line direction of the main body; a drill bit port communicated with the well-cementing fluid runner is formed in the drill bit tire body; the diameter of the first runner is smaller than that of the drilling liquid runner. A gap of a crack development stratum can be effectively blocked by injecting the well-cementing fluid, so that leakage loss is prevented; the stability of a ground layer section which easily collapses and is not stable is enhanced, a well wall is reinforced, and collapse of the well wall is prevented; after drilling is finished, a blockage removing agent can also be injected to restore the permeability of the well wall.

Description

technical field [0001] The invention relates to the field of oil and gas exploration and development, in particular to a drilling device. Background technique [0002] During the drilling process, it is often necessary to consider the safe density window of the drilling fluid. The safe density window of drilling fluid is the density range of drilling fluid. When the density of the drilling fluid exceeds the safe density window of the drilling fluid, loss of circulation often occurs; when the density of the drilling fluid is lower than the safe density window of the drilling fluid, the wellbore wall collapses and blocks out. For some areas with more complex geological conditions, especially the deep strata are mostly carbonate strata and the areas with developed fractures and caves, the safe density window of drilling fluid is relatively narrow. [0003] In order to expand the safe density window of drilling fluid, wellbore reinforcement technology can be used at present. ...

AI Technical Summary

Problems solved by technology

[0004] However, it has been proved by many practical tests that there are still problems of well wall collapse or lost circulation when using the well wall reinforcement technology in the prior art

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