This project, entitled “A New Framework for Microscopic to Reservoir-Scale Simulation of Hydraulic Fracturing and Production: Testing with Comprehensive Data from Hydraulic Fracturing Test Site (HFTS) and Other Hydraulic Fracturing Field Test Sites,” is a multi-scale modeling effort with the goal of improving the understanding of the processes that drive the mechanical and geochemical/hydrologic response to stimulation and production of shale resources. The ultimate goal is the development, application, and validation of a new framework for microscopic-to-reservoir-scale simulations of hydraulic fracturing and production, built upon a fusion of existing high-performance simulation capabilities available at four of DOE’s national labs, namely Lawrence Berkeley National Laboratory (LBNL), Lawrence Livermore National Laboratory (LLNL), National Energy Technology Laboratory (NETL), and SLAC National Accelerator Laboratory (SLAC). High-quality field data acquired from the HFTS, led by the Gas Technology Institute (GTI) and NETL at a site contributed by Laredo Petroleum in the Midland Basin, TX, are utilized for analysis, model development, and validation.

The modeling occurs across two spatial domains — the reservoir scale, which encompasses the intra- and inter-well regions, and the inter-fracture scale, which is the region between stimulated fractures. LLNL focuses on simulation of the fracture network evolution upon stimulation and the influence of geologic and engineering parameters at the reservoir scale using the GEOS coupled flow and mechanics simulator. The results of these simulations provide the mechanical boundary conditions for inter-fracture scale investigations. Furthermore, they provide model fracture networks to LBNL for reservoir-scale production simulations. At the micro-scale, LBNL uses the fluid dynamics and reactive transport Chombo-Crunch code to simulate the micro-scale physical processes occurring at the fracture-rock interfaces upon stimulation and production. Core sample analysis and laboratory studies are conducted by LBNL, SLAC, and NETL to image inter-fracture scale deformation and transport. This micro-scale modeling and imaging provides upscaled flow and transport parameters for larger-scale reservoir modeling and production optimization conducted with LBNL’s powerful multiphase Transport Of Unsaturated Groundwater and Heat (TOUGH) simulator. 

The main outcomes of the project are: (1) a validated and tested geomechanical simulation framework using the GEOS code to enable prediction of stimulated fracture network evolution and permeability enhancement, (2) an optimized workflow for reservoir-scale stimulation and production predictions linking GEOS and the multi-phase flow simulator TOUGH, and (3) an experimental and simulation framework for adequate representation of micro-scale behavior in fractured shales in reservoir-scale models, via development of new constitutive models that can be incorporated into the GEOS and TOUGH simulations.
 

Lawrence Berkeley National Laboratory
Lawrence Livermore National Laboratory
National Energy Technology Laboratory
Stanford Linear Accelerator Laboratory

The production of oil and gas from unconventional reservoirs largely depends upon two main features operating at different scales: (1) the establishment of a reservoir scale stimulated fracture network that effectively communicates with the rock volume, enhancing permeability and transport to the wellbore and (2) the coupled multi-phase flow, chemical and mechanical processes affecting the migration of hydrocarbons from the low permeability country rock adjacent to the stimulated fracture network. To date, there has been no simulation framework that allows seamless and integrated prediction of these features across spatial scales extending from the pore structure of the reservoir rock to the volume of the reservoir. In addition, there has been a lack of suitable field measurements to test such models, as stimulation and production data are often proprietary and not freely available to national laboratories and academic institutions. New multi-scale simulation capabilities are needed that are validated against recent field-based research experiments on hydraulic fracturing and shale production, such as the HFTS, a DOE-industry partnership project fielded within the Wolfcamp Formation in the Permian Basin. 

The work described here is a multi-lab effort to develop and demonstrate a new simulation framework for unconventional stimulation and production. In close collaboration with the HFTS project partners, the project (1) enhances the utilization and integration of HFTS results through the application of advanced computational tools describing geomechanics and pore to reservoir-scale transport and (2) utilizes HFTS field data and focused laboratory experiments on HFTS core samples to validate and improve existing computational tools.  

The project is expected to have important impact in terms of developing the Wolfcamp resource in the Permian Basin, a massive unconventional play, the continued development of which has substantial impact on our nation’s energy security. However, given its focus on fundamental properties and upscaling workflows, the project’s impact will be more far-reaching: the new modeling framework can be used to provide a better predictive understanding of stimulation and production processes in various unconventional oil and gas projects beyond the HFTS application. The validated simulation workflow — with an advanced geomechanical code for stimulation integrated with a multi-phase flow code for production — will provide a physics-based predictive tool for completion designs aimed at increased productivity and decreased cost as well as the assessment and minimization of the environmental impacts of hydraulic stimulation. Using these high-fidelity simulations for a range of unconventional plays and conditions will provide a suite of ground-truth predictions that can be used to train advanced machine learning approaches for basin-specific stimulation and production behavior.

GEOS-TOUGH Integration

• Developed automated procedure for coupling between GEOS fracturing simulations and TOUGH reservoir simulations 
• Developed stimulation and production models for HFTS and demonstrated efficient simulation framework

Reservoir Stimulation and Production Modeling

• Developed new understanding and new upscaling techniques for fracture "swarms", now adopted by industry 
• Investigated impact of fracture/well interference & other sensitivities on production

Micro-scale Studies

• Developed new techniques to interrogate shale/proppant behavior in single grain and monolayer configurations and conducted series of experiments in unreacted & reacted HFTS core
• Established experimental systems and modeling tools for integrated investigation of micro-scale shale alteration due to interactions with fracturing fluids

Micro- to Reservoir Upscaling 

• Developed upscaling methods for micro-scale shale/proppant behavior and reactions and how these can be accounted for in reservoir models

Year 1 — DOE Contribution: $2,300,000
Year 2 — DOE Contribution: $2,300,000
Year 3 — DOE Contribution: $725,000
Planned Total Funding: DOE Contribution: $5,325,000

NETL — Joseph Renk (joseph.renk@netl.doe.gov or 412-386-6406)
Lawrence Berkeley National Laboratory — Jens Birkholzer (jtbirkholzer@lbl.gov)
Lawrence Livermore National Laboratory — Joe Morris (morris50@llnv.gov)
National Energy Technology Laboratory — Ale Hakala (Alexandra.hakala@netl.doe.gov)
Stanford Linear Accelerator Laboratory — John Bargar (bargar@slac.stanford.edu)

Birkholzer, J.T., Morris, J., Bargar, J.R., Brondolo, F., Cihan, A., Crandall, D., Deng, H., Fan, W., Fu, W., Fu, P., Hakala, A., Hao, Y., Huang, J., Jew, A.D., Kneafsey, T., Li, Z., Lopano, C., Moore, J., Moridis, G., Nakagawa, S., Noël, V., Reagan, M., Sherman, C.S., Settgast, R.,. Steefel, C.I., Voltolini, M., Xiong, W., Ciezobka, J. (2021): A New Modeling Framework for Multi-Scale Simulation of Hydraulic Fracturing and Production from Unconventional Reservoirs, Energies, 14(3):641. 

Fu, W., Morris, J.P., Fu, P., Huang, J., Sherman, C.S., Settgast, R.R., and Ryerson, F.J. (2020): An upscaling approach to model swarming hydraulic fractures observed at the Hydraulic Fracturing Test Site in field-scale simulations, SPE Journal, SPE-199689-PA, https://doi.org/10.2118/199689-PA.

Huang, J., Fu, P., Morris, J.P., Settgast, R.R., Sherman, C. S., Hao, Y., Ryerson F.J., “Numerical Modeling of Well Interference Across Formations at the Hydraulic Fracturing Test Site,” ARMA 19–1995. 

Moridis, G.J. and M.T. Reagan (2021): Evaluation of the Effectiveness of Continuous Gas Displacement for EOR in Hydraulically Fractured Shale Reservoirs, SPE Paper 198999, SPE Journal, 2020 (In Press).

Morris, J. P., W. Fu, C.S. Sherman, P. Fu, J. Huang, Y. Hao. R. Settgast, J. Birkholzer, M. Reagan, H. Deng, G. Moridis, C. Steefel, S. Nakagawa, M. Voltolini, T. Kneafsey, Z. Li, J. Bargar, A. Jew, V. Noël, W. Fan, A. Hakala, C. Lopano, W. Xiong, D. Crandall, Moore, J. (2020): A New Framework for Microscopic to Reservoir-Scale Simulation of Hydraulic Fracturing and Production: Testing with Comprehensive Data from the Hydraulic Fracturing Field Test in the Permian Basin, ARMA 20-1721, 54th US Rock Mechanics/Geomechanics Symposium, Golden, Colorado, USA, 28 June-1 July 2020.

Voltolini, M., Barnard, H., Creux, P. and Ajo-Franklin, J. (2019): A new mini-triaxial cell for combined high-pressure and high-temperature in situ synchrotron X-ray microtomography experiments up to 400° C and 24 MPa, Journal of synchrotron radiation, 26(1).