Reconstruction method for controlling pulses through rotating speed of rotating valve

Abstract

The invention provides a reconstruction method for controlling the pulses through the rotating speed of a rotating valve. After drilling fluid pressure differential phase shift keying signals or drilling fluid pressure quadrature phase shift keying signals which are obtained from a well opening pressure sensor are subjected to signal treatment and pumping pressure interference and noise are eliminated, phase signals reflecting the carrier phase change during drilling fluid pressure differential phase shift keying modulation or phase signals reflecting the carrier phase change during drilling fluid pressure quadrature phase shift keying modulation are obtained through coherent demodulation and anti-cosine calculation, the control pulses of the rotating speed of the rotating valve are reconstructed by conducting derivative operation on the phase signals, and the reconstructed control pulses of the rotating speed of the rotating valve are not influenced by the phase error during coherent demodulation; and logical judgment is conducted on the amplitude of the constructed control pulse of the rotating speed of the rotating valve according to the data coding rule, the code element state represented by the pulses is determined, data codes are arranged according to the occurrence time sequence of the pulses, and decoding of the drilling fluid pressure differential phase shift keying signals or the drilling fluid pressure quadrature phase shift keying signals is achieved.

Description

Technical field: [0001] The invention relates to a processing method of measurement-while-drilling / logging-while-drilling uploaded signals in the process of oil and gas drilling, and in particular to a method for reconstructing rotational speed control pulses of a rotary valve. Background technique: [0002] Downhole Measurement While Drilling / Logging While Drilling (MWD / LWD) is a modern drilling auxiliary technology that measures and transmits downhole information in real time during drilling. During the drilling process, the drilling fluid is pumped downhole from the ground through the drill string, sprayed out from the water hole of the drill bit for the lubrication and cooling of the drill bit, and returns upward to the wellhead through the annular space between the well wall and the drill string. MWD / LWD tools are installed Inside the drill collar at the top of the bit, see attached figure 1 . In MWD / LWD tools, sensors installed in the drill string near the drill bit ...

AI Technical Summary

Problems solved by technology

Therefore, how to obtain the synchronization signal simply and effectively, how to eliminate the influence of the phase error on the pulse reconstruction of the rotary valve speed control during the coherent demodulation of the drilling fluid pressure PSK signal, and what method to use to process the demodulated phase signal to realize the rotation The reconstruction of valve speed control pulse is a key technical problem that needs to be solved in the field of measurement while drilling / logging while drilling, but there are no reports about effective solutions and solutions in this regard

Images