Study on identification method of gas-bearing carbonate reservoirs based on joint acoustic-resistivity experiments – an example from the Sichuan Basin of China

Abstract

Cracks and pores coexist in carbonate reservoirs, and this complex pore structure has a significant impact on acoustic and resistivity logging. Making full use of acoustic and electrical well logging data can help to identify carbonate gas reservoirs. First, this paper studies the controlling effects of different lithologies on the acoustic velocity according to the elastic theory of porous and fractured media based on joint acoustic-resistivity rock physics measurement experiments. At the same time, a theoretical gas-bearing reservoir identification template is established based on acoustic experimental data, and the gas-bearing reservoir identification template is used to qualitatively identify a gas reservoir. Then, the empirical relationship between the acoustic velocity and resistivity is derived based on the Archie equation. It is found that the formation P-wave velocity and resistivity have a power function relationship in the research area. Based on the above research, a quantitative identification template for gas-bearing reservoirs is established. The case study has verified the reliability of the gas-bearing carbonate reservoir identification method based on the above two methods.