An instantaneous negative pressure underbalanced drilling device and method

Abstract

The invention belongs to the technical field of petroleum and natural gas development, and relates to an instantaneous negative pressure underbalanced drilling device and method. Drilling is realized by adding an instantaneous negative pressure underbalanced drilling device into the drill string, and the upper joint is driven by the upper drill string at a uniform clockwise speed. When rotating, the instantaneous negative pressure underbalanced drilling device vibrates upwards driven by the drill string, the ball blocks the annular drilling fluid channel, and the upper diversion fluid presses the annular drilling fluid in the sleeve flow channel to increase the pressure, while the lower diversion joint The annular drilling fluid in the flow channel reduces the pressure and forms an instantaneous negative pressure at the bottom of the well; when the drill string vibrates downward, the flow channel of the lower diversion joint opens, the annular drilling fluid circulates normally, and the upper diversion compresses the sleeve flow The annular drilling fluid in the channel and the lower diversion joint flow channel is connected, and the pressure recovery is equal; such circulation realizes instantaneous negative pressure underbalanced drilling; its structure is simple, easy to use, safe and reliable, does not consume drilling fluid energy, and does not affect drilling tools The structure, processing and manufacturing and use and maintenance costs are low.

Description

Technical field: [0001] The invention belongs to the technical field of petroleum and natural gas development, and relates to an instantaneous negative pressure underbalanced drilling device and method for reducing drill string vibration and increasing mechanical drilling speed. Background technique: [0002] During oil and natural gas drilling, the drill string and the annular space are filled with drilling fluid. Its main functions include balancing formation pressure, carrying cuttings, and cooling the drill bit, among which balancing formation pressure is an important guarantee for the safe drilling process. Due to the existence of drilling fluid, the rock at the bottom of the well is in a three-dimensional stress state due to the huge liquid pressure, and its shape is enhanced, making it more difficult to break. increase, the difficulty of rock breaking increases rapidly, the ROP decreases, and the drilling cycle is prolonged. On the other hand, when the drilling fluid...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art, aiming at the problems of low ROP and serious reservoir pollution in the process of balanced and overbalanced drilling, to provide an instantaneous negative pressure underbalanced drilling device and method, reducing the drill string At the same time of longitudinal vibration, the axial vibration energy of the drill string is used to generate periodic instantaneous negative pressure at the bottom of the well, which reduces the rock breaking strength, improves rock breaking efficiency and ROP, reduces drilling capital investment, and protects the reservoir to a certain extent. layer from contamination

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