High Precision Porosity Inversion Of Reef And Bank In Carbonate

Foreland basin, the ancient uplift and marine carbonate rocks are the three most important field of oil and gas exploration. Strengthening the research of marine carbonate rocks has great significance. The porosity is an important parameter to characterize the oil and gas reservoir characteristics, this parameter is obtained from the inversion of seismic data for oil and gas field exploration and development is important.Many studies have confirmed that the reservoir pore structure have a great impact on the acoustic velocity.This paper according to the difficulties of carbonate reservoir prediction, seismic response characteristics and logging response characteristics of carbonate reservoir, taking XX Feixianguan group and Changxin group of reef reservoir as an example, Do the depth study of carbonate porosity prediction technology and application. First, introduce in detail the logging response characteristics of the region.; Second, the serious discussion of the properties optimized porosity inversion,the conventional porosity inversion, the distance-weighted porosity inversion and porosity inversion based on the the Gassmann equation. The paper use the classic rock physics model with pore shape factor to construct the rock structure parameters an discuss its effect on elastic properties of rock then use the method of statistical analysis to establish the relationship between the elastic modulus for the porosity inversion based on the Gassmann equation. Through the calculation of the physical test data and logging data, show that small changes of the rock structure parameters may affect the calculation of porosity.After the porosity prediction of a single well using rock physical model,we compare and analysis the conventional porosity,the distance-weighted porosity and the Gassmann equation based porosity. Calculation of porosity after considering rock structure parameters, can significantly improve the prediction accuracy of porosity, and decrease the error accumulation effect obviously. In order to improve the prediction accuracy of the Gassmann equation based porosity inversion, we do the distance-weighted to the porosity prediction, and improve the prediction precision. Third, the paper use phase control method to constrain the porosity inversion further, let the reservoir prediction more accurate. In summary, porosity inversion method can be used to describe the carbonate reservoir, and to provide evidence for the deployment of drilling, reduce failure rate.