A Post-Drilling Inversion Method for Highly Deviated Well/Horizontal Well Electromagnetic Logging Data While Drilling

Abstract

The invention discloses a post-drilling inversion method of electromagnetic wave logging data while drilling a highly deviated well / horizontal well. The inversion method includes the following steps: s1. Obtain the logging data of adjacent pilot wells, and extract the horizontal resistivity sequence of the reservoir; s2. Based on the imaging data of highly deviated wells / horizontal wells while drilling, determine the formation interface position and dip angle information ; s3. Process the strata divided by step s2 layer by layer, and establish a simplified one-dimensional three-layer inversion model to reduce the number of inversion parameters; s4. According to the variation range of the horizontal resistivity sequence of the reservoir extracted in step s1, Apply geological constraints to the inversion parameters; s5. Adaptively initialize the inversion parameters with multiple initial values; s6. Use the adaptive multiplier regularization Gauss-Newton algorithm to iteratively update the stratigraphic model; s7. Optimize and output the inversion results . The method of the invention improves the speed and precision of post-drilling inversion of highly deviated wells / horizontal wells while drilling electromagnetic wave logging.

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

Images