公开(公告)号：US20210238955A1

公开(公告)日：2021-08-05

申请号：US17169204

申请日：2021-02-05

Applicant: University of Electronic Science and Technology of China

Inventor： Hua WANG ,  Xingming WANG ,  Yukun FU

IPC: E21B34/08 ,  E21B34/16 ,  E21B47/06

Abstract: The present invention discloses a method for controlling a toe-end sliding sleeve in a horizontal well based on efficient decoding communication. The method comprises the following steps: forming a pressure wave signal by adjusting and controlling a pressure value in a wellbore according to a first preset encoding manner; acquiring a pressure value change signal in the wellbore, determining a reference time by using an STA/LTA method, and predicting pressure value to acquire a predicted pressure value signal curve; identifying a toe-end sliding sleeve control command in the acquired pressure wave signal by using a first preset decoding manner based on the fitness between the acquired pressure value signal curve and the predicted pressure value signal curve; and driving the toe-end sliding sleeve to perform actions according to the toe-end sliding sleeve control command. The method disclosed by the present invention is simple to operate, low in communication error rate, and aimed to solve the technical problems of complicated system of wellbore pressure test and sliding sleeve joint operation, high operation complexity, high bit error rate of pressure pulse communication, and long code element transmission time in the existing solutions in the prior art.

公开(公告)号：US20230033271A1

公开(公告)日：2023-02-02

申请号：US17962511

申请日：2022-10-09

Applicant: University of Electronic Science and Technology of China

Inventor： Hua WANG ,  Meng LI

IPC: E21B47/005 ,  G01V1/50

Abstract: A reverse time migration imaging method for cased-hole based on ultrasonic pitch-catch measurement, including: calculating a theoretical dispersion curve; expanding original Lamb data of two receivers into array waveform data based on phase-shift interpolation; establishing a two-dimensional migration velocity model including density, P-wave velocity and S-wave velocity of a target area; generating and storing a forward propagating ultrasonic wavefield for each time step; reversing a time axis; generating and storing a reversely propagating ultrasonic Lamb wavefield for the two receivers after phase-shift interpolation; calculating envelopes of the forward propagating ultrasonic Lamb wavefield and the reversely propagating ultrasonic Lamb wavefield; applying a zero-lag cross-correlation imaging condition to obtain reverse time migration imaging results; and applying Laplace filtering to suppress low-frequency imaging noises in the imaging results.