US 11,913,324 B2
Downhole multidimensional imaging feature extraction method and imaging apparatus
Yijin Zeng, Beijing (CN); Wei Zhang, Beijing (CN); Weining Ni, Beijing (CN); Xin Li, Beijing (CN); Lipeng Yan, Beijing (CN); Jinping Wu, Beijing (CN); Yuefa Hu, Beijing (CN); Lishuang Wang, Beijing (CN); Zuyang Zhu, Beijing (CN); and Jintai Mi, Beijing (CN)
Assigned to CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and SINOPEC RESEARCH INSTITUTE OF PETROLEUM ENGINEERING, Beijing (CN)
Appl. No. 17/753,481
Filed by CHINA PETROLEUM & CHEMICAL CORPORATION, Beijing (CN); and SINOPEC RESEARCH INSTITUTE OF PETROLEUM ENGINEERING, Beijing (CN)
PCT Filed Aug. 26, 2020, PCT No. PCT/CN2020/111392
§ 371(c)(1), (2) Date Mar. 3, 2022,
PCT Pub. No. WO2021/043043, PCT Pub. Date Mar. 11, 2021.
Claims priority of application No. 201910837890.4 (CN), filed on Sep. 5, 2019.
Prior Publication US 2022/0333478 A1, Oct. 20, 2022
Int. Cl. E21B 47/002 (2012.01); E21B 47/13 (2012.01); E21B 47/18 (2012.01); E21B 47/017 (2012.01)
CPC E21B 47/0025 (2020.05) [E21B 47/13 (2020.05); E21B 47/18 (2013.01); E21B 47/017 (2020.05)] 5 Claims
OG exemplary drawing
 
1. An apparatus for downhole multi-dimensional imaging, comprising:
an acquisition unit, configured to acquire a formation resistivity signal, an ultrasonic echo signal, and an orientation signal regularly from a borehole being drilled into a formation;
a sector calculation unit, configured to calculate, based on said orientation signal, a sector of borehole where a currently acquired signal is from;
a multi-dimensional imaging unit, configured to calculate, based on the formation resistivity signal and the ultrasonic echo signal acquired by the acquisition unit, data of resistivity, of distance from a drilling tool to a borehole wall, and of ultrasonic echo amplitude, and distribute said data of resistivity, of distance from a drilling tool to a borehole wall, and of ultrasonic echo amplitude into all sectors of the borehole, so as to generate multi-dimensional imaging data including imaging data of the resistivity, imaging data of the distance from the drilling tool to the borehole wall, and imaging data of the ultrasonic echo amplitude; and
a formation feature recognition unit, configured to perform feature recognition and extraction on the imaging data of the resistivity, the imaging data of the distance from the drilling tool to the borehole, and the imaging data of the ultrasonic echo amplitude, so as to obtain key features characterizing the formation being drilled, said key features being transmitted to ground for guiding drilling process,
wherein the formation feature recognition unit is configured to:
select the imaging data of the resistivity along a perimeter of a borehole perimeter in a latest depth, which is represented by a two-dimensional array Rxy, where x is coordinate along the perimeter of the borehole, and y is coordinate of a depth of the borehole;
calculate an average resistivity for the imaging data of the resistivity in a first row of the two-dimensional array Rxy;
search, from a second row of the two-dimensional array Rxy, an imaging data of the resistivity, which has a difference between its own resistivity and the average resistivity larger than a predetermined threshold, in sequence; and
record subscript values of said image data of the resistivity and store the subscript values in an array Ua, in order to calculate said key features.