Response simulation and corresponding analysis of dual laterolog in cavernous reservoirs

Abstract

Abstract To figure out the response characteristics of dual laterolog logging in carbonate and volcanic cavernous reservoirs, the parameters of laboratory formation model and tool were optimized on the basis of numerical simulation, then, the experimental data was used to calibrate the numerical simulation results. Finally, the response characteristics of cavernous formations in the original formation condition were acquired. The results show that the radial radius and height were set to 1 and 2 meters, meanwhile the length of dual laterolog in vertical and radial direction were reduced to 1/20 and 1/6, which can satisfy the need of laboratory experiments and there is a good match between experimental data with numerical results under the same circumstance. The numerical simulation parameters calibrated by physical modeling experiment were used to find out the dual laterolog response characteristics of cavernous formations. The results show the apparent resistivity on the dual laterolog by the well bore is the lowest at the cave center, and the apparent resistivity could not accurately reflect the infill resistivity of the cave; the larger the radius of the cave, the lower of the infill resistivity and the smaller the distance between the cave and the well bore, the more sensitive dual laterolog will be to caves in formations. The distance between the cave boundary and well wall that could be recognized by deep laterolog is less than 0.5 m, as for shallow laterolog, the largest distance is 0.3 m.