Integrated Approach for the Petrophysical Interpretation of Post- and Pre-Stack 3-D Seismic Data, Well-Log Data, Core Data, Geological Information and Reservoir Production Data via Bayesian Stochastic Inversion

Torres-Verdin, Carlos ; Sen, Mrinal K.

University of Texas at Austin

关键词: Data Analysis;    02 Petroleum;    Seismic Surveys;    Production Logging;    Sensitivity Analysis;   

DOI  :  10.2172/825256
RP-ID  :  NONE
RP-ID  :  FC26-00BC15305
RP-ID  :  825256

美国|英语

来源: UNT Digital Library

【 摘 要 】

The present report summarizes the work carried out between September 30, 2002 and August 30, 2003 under DOE research contract No. DE-FC26-00BC15305. During the third year of work for this project we focused primarily on improving the efficiency of inversion algorithms and on developing algorithms for direct estimation of petrophysical parameters. The full waveform inversion algorithm for elastic property estimation was tested rigorously on a personal computer cluster. For sixteen nodes on the cluster the parallel algorithm was found to be scalable with a near linear speedup. This enabled us to invert a 2D seismic line in less than five hours of CPU time. We were invited to write a paper on our results that was subsequently accepted for publication. We also carried out a rigorous study to examine the sensitivity and resolution of seismic data to petrophysical parameters. In other words, we developed a full waveform inversion algorithm that estimates petrophysical parameters such as porosity and saturation from pre-stack seismic waveform data. First we used a modified Biot-Gassmann equation to relate petrophysical parameters to elastic parameters. The transformation was validated with a suite of well logs acquired in the deepwater Gulf of Mexico. As a part of this study, we carried out a sensitivity analysis and found that the porosity is very well resolved while the fluid saturation remains insensitive to seismic wave amplitudes. Finally we conducted a joint inversion of pre-stack seismic waveform and production history data. To overcome the computational difficulties we used a simpler waveform modeling algorithm together with an efficient subspace approach. The algorithm was tested on a realistic synthetic data set. We observed that the use of pre-stack seismic data helps tremendously to improve horizontal resolution of porosity maps. Finally, we submitted four publications to refereed technical journals, two refereed extended abstracts to technical conferences, and delivered two oral presentation at a technical forum. All of these publications and presentations stemmed from work directly related to the goals of our DOE project.