Hydraulic pulse supercharging underbalance drilling unit

Abstract

The invention relates to a hydraulic pulse supercharging underbalance drilling unit comprising a body with two oblique flow passages, an impeller, a base, an impeller shaft and the like. The base is mounted in the body through positioning pins, and two effusion passages are symmetric to a plane of the two oblique flow passages on the body. The impeller is mounted above the base through the impeller shaft. A basic operating principle includes that drilling fluid passes an inner cavity of the device body to drive the impeller to rotate, baffles under the impeller can periodically open and close the effusion passages of the base so as to change sectional area of fluid passing, the continuous drilling fluid flowing through the device is modulated into a pulse form, and accordingly rock clearing efficiency is improved; when the effusion passages are opened and closed periodically, lateral openings of the impeller can correspondingly close and open the oblique flow passages to enable the drilling fluid to be ejected upwards, pressure is increased on a drill bit by generated reactive thrust, suction pressure is generated in annuluses under the oblique flow passages to realize underbalance, and finally rock-breaking efficiency is improved. The hydraulic pulse supercharging underbalance drilling unit is simple in structure, hydraulic pulse drilling technology, downhole supercharging drilling technology and underbalance drilling technology are combined ingeniously, downhole hydraulic energy is distributed reasonably, rock breaking efficiency and rock clearing efficiency are improved substantially, and drilling cost is saved.

Description

technical field [0001] The invention relates to a hydraulic pulse pressurized underbalanced drilling device. The utility model belongs to a downhole tool used in drilling in the field of oil and natural gas exploitation. Background technique [0002] As the exploration and development of oil and gas resources develops towards deep strata, more and more deep wells and ultra-deep wells are drilled. As the drilling depth continues to increase, the hydrostatic column pressure of the drilling fluid column in the wellbore continues to increase. The holding effect of cuttings is becoming more and more obvious; however, the transmission, conversion, distribution and utilization efficiency of hydraulic energy in the traditional drilling method during the drilling process further decreases with the increase of well depth. This directly leads to a significant drop in drilling speed. Therefore, how to improve the stress state and flow field distribution of the bottom rock by improving...

AI Technical Summary

Problems solved by technology

Although in recent years some scholars have developed tools to increase drilling speed, such as rotary percussion drilling tools, downhole superchargers and single hydraulic pulse drilling tools, but due to the complex internal components, the life and stability are poor, and the high pressure water jet produced by the downhole supercharger The auxiliary rock-breaking energy is low, the rock-breaking effect is average, the pulsation amplitude generated by a single pulse generator is small, and the pressure drop and energy loss are large, so it has not been promoted as a large-scale application technology.

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