After-drilling inversion method for while-drilling electromagnetic wave well-log data of high deviated well/horizontal well

Abstract

The invention discloses an after-drilling inversion method for while-drilling electromagnetic wave well-log data of a high deviated well / a horizontal well. The inversion method comprises the followingsteps of s1, obtaining adjacent pilot well log data, and extracting a reservoir horizontal resistivity sequence; s2, based on while-drilling imaging data of the high deviated well / the horizontal well, determining stratigraphic interface position and tilt angle information; s3, performing layer-by-layer processing on divided stratums in the step s2, and building a simplified one-dimensional three-layer inversion model to reduce inversion parameters; s4, according to a change range of the reservoir horizontal resistivity sequence extracted in the step s1, applying geological constraints to theinversion parameters; s5, performing multi-initial value adaptive initialization on the inversion parameters; s6, performing iterative updating on a stratigraphic model by utilizing an adaptive multiplier regularization Gauss-Newton algorithm; and s7, optimizing and outputting an inversion result. The method improves the speed and precision of after-drilling inversion of while-drilling electromagnetic wave well-log of the high deviated well / the horizontal well.

Description

technical field [0001] The invention relates to the field of petroleum exploration and development, and belongs to the category of electrical logging methods, in particular to a post-drilling inversion method for electromagnetic wave logging data of highly deviated wells / horizontal wells while drilling. Background technique [0002] During the drilling of highly deviated wells / horizontal wells, the "corner" of the apparent resistivity curve of electromagnetic logging while drilling is a good indicator of the formation interface, but it is much higher than the true resistivity of the reservoir. a huge challenge. At the same time, affected by the proximity of the stratum to the stratum boundary, relative dip angle and anisotropy, the apparent resistivity curves at different detection depths are seriously separated, and it is difficult to obtain the true resistivity of the stratum. Therefore, accurate inversion of true formation resistivity information is one of the key issues...

AI Technical Summary

Problems solved by technology

Up to now, the rapid inversion of electromagnetic logging data while drilling mainly has the following four problems in the fine evaluation of reservoirs after drilling: 1) The multi-layer model used in the inversion calculation is slow; 2) The multi-layer model has many inversion parameters. , Jacobian has a large amount of calculation; 3) The multi-layer inversion model assumes that the dip angles of all layers are consistent, and the accuracy of the inversion results in stratigraphic structures with rapidly changing dip angles is reduced; 4) From the perspective of optimization, there are multiple local poles in the objective function. Small values, the inversion results tend to be trapped in local minima

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