Quick evaluation for optimal recovery in tight reservoirs: a workflow combining seismic data, geomechanics, and fracture models

Oct 20, 2021 | Lecture Archive

Reinaldo Michelena (SeisPetro Geoconsulting)

This talk describes a workflow to estimate recovery in tight reservoirs that uses flow simulation models constrained by seismic data, geomechanical parameters, and hydraulic stages properties. The goal of the workflow is the rapid testing of different hydraulic stage scenarios in the presence of natural fractures and other hypotheses that can be compared to select the one that yields optimal recovery. All the parameters of interest are generated directly into a flow simulation grid centered on the horizontal well. Thickness of hydraulic stages equals that of one cell of the simulation grid and therefore, details of individual hydraulic fractures are not explicitly considered, allowing modeling of larger reservoir scale effects on recovery. The first step is the estimation of natural fracture orientations using seismic data calibrated with independent fracture information. Then, the flow grid is also populated with geomechanical parameters such as stress field and stress orientations, pore pressure, and friction coefficient. After defining locations and geometry of hydraulic stages along the well path and assuming fluid pressure decay functions away from the hydraulic stages, we use Mohr-Coulomb faulting theory to estimate which natural fractures are more prone to reactivation after hydraulic stimulation. This volume of reactivated natural fractures is then upscaled to effective fracture permeability that serves as input to an ultra-fast dual-permeability flow simulator. Finally, once the model is in the flow simulator, we use fluid properties and other dynamic parameters for calibrating with production information, changing the simulation model if needed, and performing long-term forecast. The application of the workflow is illustrated using a dataset from the Eagle Ford formation (South Texas) that consists of 3D seismic, outcrop descriptions, microseismic data, geomechanics measurements, and production information.

About the author
Reinaldo received a B.S. in physics from Universidad Simón Bolívar (Venezuela) and a Ph.D. in Geophysics from Stanford University. He has 35 years of experience in research, development, and application of seismic, petrophysics, and geological modeling methods for reservoir characterization. He worked 18 years for PDVSA-Intevep in Venezuela and 13 years for iReservoir, a consulting firm in the area of reservoir characterization and flow simulation.  In 2017, he started SeisPetro Geoconsulting to continue the development and application of advanced techniques for reservoir characterization and modeling in conventional and unconventional reservoirs. He served as Associate Editor of the journal Geophysics in the area of seismic inversion and was Chairman of the Board of the magazine The Leading Edge. More recently, he was honored with the Life Membership Award of the Society of Exploration Geophysicists.


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