A Double Crossed Dipole Logging Method

Abstract

The invention relates to a double-crossing dipole well-logging method. The method includes arranging four cross dipole transmission transducers in each of a first plane and a second plane which are perpendicular to axis, wherein angle interval of any cross dipole transmission transducer in two groups of the cross dipole transmission transducers is (2n+1)x45 degrees, and n is equal to 0, 1, 2 or 3. Each of a first-group receiving transducer array and a second-group receiving transducer array comprises 4xN receiving units which are arranged at equal intervals, N is equal to 1 or 2, and angle interval between any receiving unit in the first-group receiving transducer array and the second-group receiving transducer array and any cross dipole transmission transducer in the first plane and the second plane is nx90 degrees; the receiving transducer arrays receive signals transmitted by the cross dipole transmission transducers to acquire two groups of data signals. Consequently, through the dipole transmission transducers and the receiving transducer arrays, anisotropy parameters can be determined quickly and reliably by simply processing each group of data.

Description

technical field [0001] The invention relates to the technical field of formation surveying, in particular to a double crossed dipole logging method. Background technique [0002] In the field of oil and gas exploration, since the development of unconventional oil and gas exploration has been paid more and more attention, the quantitative evaluation of formation fractures and stress in the well logging before oil and gas development is becoming more and more important. The cross-dipole acoustic logging method can better detect the anisotropy caused by fractures or ground stress, so the cross-dipole acoustic logging method has become one of the important methods for unconventional oil and gas exploration. [0003] Schematic diagram of crossed dipole logging figure 1 As shown, four transmitting transducers are set at a certain position of the logging tool, of which two transmitting transducers are set in the specified X, -X directions, and the other two are set in the specifie...

AI Technical Summary

Problems solved by technology

[0006] However, these dipole logging techniques have at least the following disadvantages: when the angle between the transmitting transducer of the crossed dipole and the fast and slow shear waves is around 45 degrees, the medium with strong anisotropy is also weak in the four-component data display. , which is not conducive to anisotropy detection and inversion. If the data of the four components are used to simultaneously or partially invert the two parameters of anisotropy, azimuth angle jumps may occur

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