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

Abstract

The present report summarizes the work carried out between September 30, 2000 and September 30, 2004 under DOE research contract No. DE-FC26-00BC15305. During the three-year project period, we carried out extensive studies on the inversion post-stack and pre-stack data together with well logs, petrophysical information and fluid flow data. We have achieved all the project goals including development of algorithm for joint inversion of pre-stack seismic data, well logs, and time records of fluid production measurements using stochastic inversion algorithms which were demonstrated on realistic synthetic and field data. Our accomplishments are:• Joint inversion of post-stack seismic, well log, fluid flow, and petrophysical data: we demonstrated the technique with application to data from the Gulf of Mexico.• Development of a robust pre-stack full waveform inversion algorithm: A new approach based on iteration-adaptive regularization that makes use of plane wave transformed seismic data, was developed and applied to OBC dataset from the Gulf of Thailand. The algorithm was also implemented on a cluster of personal computers.• Joint inversion of pre-stack seismic and well-log data: A new stochastic optimization algorithm that makes use of the essential features of seismic and well log data was developed and tested on realistic synthetic dataset.• Joint inversion of pre-stack seismic and fluid flow data: A novel technique was developed to optimally combine seismic and flow data. The technique makes very realistic estimate of porosity; sensitivity of the flow parameters to two disparate datasets was studied extensively. DE-FC26-00BC15305iv • Direct estimation of petrophysical parameters from seismic data: The pre-stack waveform inversion was modified to invert directly for porosity and saturation using the BiotGassmann equation at each iteration step.The final report contains abridged versions of some of our inventions. The works resulted in several peer-reviewed publications. Five papers have been communicated for peer-reviewed publication, and seven papers were presented at conferences. All of these publications and presentations stemmed from work directly related to the goals of our DOE project.