Device and method for controlling RWD (reaming while drilling) drilling pressure distribution relationship

Abstract

The invention discloses a device for controlling RWD (reaming while drilling) drilling pressure distribution relationship, and belongs to the field of drilling equipment. The device comprises an RWD device (1), a short drill collar (2) and a pilot bit (3), wherein the RWD device (1) is connected with the upper end of the short drill collar (2), the lower end of the short drill collar (2) is connected with the pilot bit (3), at least one reaming cutter assembly (11) is arranged on the RWD device (1), and the diameter of the pilot bit (3) is smaller than the outer diameter of the RWD device (1) in the expansion state of the reaming cutter assembly (11). The invention also discloses a method for utilizing the device for controlling the RWD drilling pressure distribution relationship. The RWD drilling pressure distribution relationship can be controlled within the set range through regulating the cutting depth per revolution of the pilot bit and the cutting capability of a seaming device, and the safety and the stability of the reaming process are enhanced.

Description

technical field [0001] The invention relates to the field of drilling equipment, in particular to a device and a method for controlling the distribution relationship of reaming-while-drilling-while-drilling drilling pressure. It can reasonably adjust the weight-on-bit distribution relationship in the reaming-while-drilling process, and improve the safety and stability of the reaming operation. Background technique [0002] In the reaming while drilling process of drilling technology, the distribution relationship between the pressure on bit and the reamer while drilling is one of the parameters that need special attention. If the stick-slip or severe lateral vibration of the drill string occurs, the drilling tool will be damaged prematurely, and the ROP will decrease accordingly. [0003] The weight-on-bit distribution relationship is generally expressed by the ratio of the weight-on-bit of the pilot bit and the reamer while drilling, and it is generally agreed that the wei...

AI Technical Summary

Problems solved by technology

This method involves a single factor and the accuracy rate is not high. Therefore, it is difficult to correctly match the pilot drill bit and reamer required for the design of reaming while drilling.

[0007] In the existing technology, the borehole wall is regarded as a thick-walled barrel subject to internal and external pressure, and the difference in compressive strength of the formation cut by the pilot bit and the reamer while drilling is analyzed, and a ladder effect index that characterizes the above difference is proposed and introduced into the Calculation of weight-on-bit distribution ratio, but this method assumes that the rock cutting power of the reamer while drilling and the pilot bit are the same, and the applicable field is narrow

[0008] In the process of realizing the present invention, the inventor found that the prior art has at least the following problems: the existing drilling tools cannot reasonably adjust the weight-on-bit distribution relationship in the process of reaming while drilling, and there is greater safety in the reaming operation and stability hazards; and there is no effective method to guide the design of the reamer while drilling and the pilot bit to ensure that the weight on bit distribution ratio is within a reasonable range

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