Exploration and Development GeophysicsEducation and Research (EDGER)

2014 Prospectus

The UT-Austin EDGER Forum is a consortium of petroleum producing and service companies focused on educating graduate students and conducting research on development and application of geophysical methods to support exploration and development of petroleum reserves. The Forum also coordinates education and technology transfer between producing and service companies and academia.

RESEARCH: Pushing the limits of seismic resolution

In the past decade, efforts have increased to search for hydrocarbons in difficult areas and in unconventional and fractured reservoirs. This search prompted acquisition of multi-azimuth and wide-azimuth datasets and development of processing algorithms using more complete physics of wave propagation. Currently the primary focus of EDGER is on advancement in quantitative seismic interpretation (QSI). This involves development of advanced techniques for high-resolution estimates of reservoir properties by integrating disparate datasets observed at multiple scales. The scope of research encompasses three major themes:

Development of new techniques for seismic imaging and inversionDevelopment of new rock physics models and adaptation of existing rock physics models to a particularfield under investigationIntegration of seismic inversion and rock physics models using novel statistical approaches and validation with field datasets

Our imaging and inversion efforts include development of new theory and numerical algorithms for forward seismic modeling that are computationally efficient and accurate. These are used in full waveform imaging and inversion. Inversion for reservoir parameter estimation will be carried out using hybrid Markov Chain Monte Carlo methods. Effective medium models are being tested by computing the seismic responses of realistic rock models based on distributions of rock properties. We are developing new data integration techniques using geostatistical methods and Bayesian analysis.

EDUCATION

A principal objective of the EDGER Forum is the education of students who have expressed interest in employment in the petroleum industry. About 1/3 of the graduate students associated with the Forum are seeking MS degrees, and our students commonly serve summer internships in the industry. The current enrollment of graduate students associated with the Forum is 13, with 5 students (4 MS/1 PhD) graduating in the last calendaryear. Since 2000, approximately 45 graduate students have completed degrees (34 MS / 13 PhD).

www.jsg.utexas.edu/edger/

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EDGER Prospectus 2014

CURRENT AND PLANNED RESEARCH

1. Seismic Modeling, imaging and inversion 1.1 Spectral Element (SEM) and Discontinuous Galerkin (DG) finite element methods for numerical

simulation of wave propagation in 3D: We are continuing our efforts in estimating errors in FE and FD methods. At the same time we are developing a 3D DG code that is capable of incorporating realistic fractures. We are addressing how the true microstructure of a rock affects the elastic properties, and thus, the seismic velocities. This is a developing subject through the use of digital rock physics where elastic moduli are obtained from numerical wave propagation experiments through segmented images using the discontinuous Galerkin method.

Left wavefield snapshot of the vertical component of wave motion taken after 0.43 seconds of wave

propagation and zoomed in to the top 1,200 meters of the model. Fracture spacing is 100 m. the interference patterns in the snapshot appear as backscattered energy in the synthetic seismograms.

1.2. 3D wave propagation modeling on GPU/CPU: We are developing an algorithm for modeling

seismic wave propagation in 3D by making use of parallel computation using CPU and GPU. We are able to obtain significant speed-up in computation.

1.3. Full waveform inversion using hybrid optimization methods: FWI methods are generally based on

local optimization and are highly sensitive to the choice of a starting model. Our proposed hybrid methods make use of the salient features of global and local optimization methods such that the dependence on the starting model is significantly reduced. At the same time, convergence can be attained rapidly by using powerful gradient information.

1.4. Pre-stack reverse-time migration (RTM) in frequency-ray parameter domain: We are developing a

new RTM algorithm that reduces the data volume significantly and thus will perhaps reduce the computational burden of RTM. Feasibility of least squares migration in the coupled ray-parameter domain is also being examined.

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Wavefield in a 3D domain with a 1 km x 1 km horizontal fracture.

2. Seismic Inversion for reservoir characterization 2.1 Transdimensional inversion: In the past year, we developed a basis pursuit inversion (BPI) scheme

and a fractal based stochastic inversion algorithm for reservoir parameter estimation. Currently we are focusing on one fundamental question: “How many layers are constrained by seismic data?” In other words, in our transdimensional inversion, the number of layer parameters is also a variable that we solve for. The optimization will be carried out using Hamiltonian Monte-Carlo approach.

2.2 Quantitative fracture characterization: Most recently we extended the AVOA method to directly

estimate fracture weaknesses that can be directly related to fracture density. Our current effort is to extend this algorithm to orthorhombic media.

3. Advanced Rock Physics Modeling

3.1 Anisotropic rock-physics modeling for the Haynesville Shale: Rock-physics models link rock properties and seismic responses, thus enabling a quantitative approach to seismic interpretation. Intrinsic anisotropy resulting from alignment of platy clay minerals and non-spherical pores differentiate shale from conventional reservoir rocks. This high degree of anisotropy affects both the seismic response and log measurements, and should be accounted in rock-physics modeling. We investigate anisotropic rock physics modeling by using rock types and anisotropic effective medium models. The effective medium models consist of distributions of minerals, mineral moduli, pore types, and orientation functions.

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Modeled c33 stiffness for porosity 0-18% with correlated normal distribution of clay mineral shape and pore shape for Rock Type 1 (a). The mean aspect ratio of clay mineral varies from 0.2 to 0.7 and the corresponding mean aspect ratio of the pore is 1/2 of clay minerals. Scattered magenta dots are log measurements. (b) Crossplot of horizontal and vertical P-wave velocities, calculated from modeled rock stiffness, of Rock Type 1. Anisotropy increases from bottom right to top left.

3.2 Quantitative Seismic Interpretation: Integration of rock physics modeling and seismic inversion. Our

recent applications of rock physics and seismic inversion for reservoir characterization have been in the areas of unconventional reservoirs and for CO2 injection for EOR and storage. In either case, the heterogeneity of the reservoirs must be accounted as well as pertinent geologic factors such as cementation or geophysical factors such as anisotropy. Our seismic-scale estimates are derived through rigorous rock-physics modeling done at the well log and core scale scales and validated at test wells. This integrated approach also provides uncertainty estimates at every step of the forward and inverse problems.

a) Clay fraction estimation. The hot colors indicate large values, and cold colors indicate smaller values. The clay fraction is correlated with VP/VS. b) Standard deviation of the clay fraction estimation, showing the estimation uncertainty. The black dashed line indicates Well A.

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The top of the reservoir colored to pore fluid composition. Red indicates pure brine and blue

indicates pure CO2. The white dot located at inline 1060 and cross line 290 is the location if CO2 injection for EOR purposes.  

FORUM One of the major benefits of participation is, perhaps, “community activities” sponsored by the Forum. Symposia and workshops have provided a platform for exchange of ideas between industry members (contractors, equipment manufacturers and producers), academics and the graduate students. Discussions of research directions by industry and academic participants have led to student and faculty research projects. The EDGER Forum is in an excellent position to facilitate communication between the various elements to encourage participation within the exploration and development geophysics community.

Research Team

Dr. Mrinal K. Sen , Co-principal Investigator Mrinal K. Sen is a professor and holder of Jackson chair in Applied Seismology with joint appointment at the institute for Geophysics and the department of Geological Sciences. His research interests include seismic wave propagation and inverse theory. He has co-authored two books on geophysical inversion. His group has been engaged in developing new techniques for seismic modeling and inversion including data integration for subsurface model building.

Dr. Kyle T. Spikes, Co-principal Investigator Kyle T. Spikes joined the Faculty in 2009 as an Assistant Professor with a focus in rock physics. His interests primarily involve the integration of geologic information with quantitative tools for seismic reservoir and basin characterization. This area of research includes both forward and inverse problems that combine rock physics, stochastic geologic modeling, and seismic-attribute analysis. Dr. Robert H. Tatham, EDGER forum advisor Robert Tatham is Professor Emeritus at the Jackson School of Geosciences and the founder of the EDGER Forum. He has been actively involved in all aspects of geophysical methods applied to petroleum problems for over 45 years. His research activities have included seismology applied to exploration, development and production of hydrocarbons. Recent activities have expanded these efforts to include characterization of the most productive parts of resource shales.

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Margo C. Grace, Project Coordinator Margo is responsible for organizing, developing and promoting events including workshops, symposia and meetings. She maintains websites and databases and develops member services as well as overseeing the budget, sponsor contracts and the financial status of EDGER Forum funds. Thomas E. Hess, Applications Manager Mr. Hess provides crucial technical support for the EDGER Forum’s research efforts as Seismic Applications Software Manager. He oversees seismic data sets from our sponsors and supports graduate students, faculty and researchers for the Exploration Geophysics program in the Dept. of Geological Sciences as well as for the UT Institute for Geophysics. Current EDGER Graduate Students:

Badr Alulaiw, Advisor: Sen, Ent Fall 2014

Anthony Barone, Advisor: Sen, Ent. Fall ‘14, MS

Pan Bei visiting student from China (advisor: Sen)

Reetam Biswas, Advisor: Sen Ent. Fall 2014

Barry Borgman, Advisor: Spikes, Ent. Fall 2014 MS

Armando Calderon visiting student from Mexico (advisor: Sen)

Russell Carter, Advisor: Spikes, Ent. Fall ‘10, PhD

Elliot Dahl, Advisor: Spikes, Ent. Fall ‘13, PhD

Debanjan Datta, Advisor: Sen, Fall ‘13, PhD

Patrick Gustie, Advisor: Tatham, Ent. Fall ‘12, MS

Han Liu, Advisor: Sen/Spikes, Ent. Fall ‘12, PhD

Qi Ren, Advisor: Spikes/Sen, Ent. Fall ‘12, PhD

David Tang, Advisor: Spikes, Ent. Fall ’14, PhD

Andrew Yanke, Advisor: Spikes, Ent. Fall ’14

Zeyu Zhao, Advisor: Sen, Ent. Fall ‘11, PhD

Recent Accomplishments

2014 SEG Abstracts • A comparison of monolithic methods for elastic wave propagation in media with a fluid-solid

interface, J. D. De Basabe and M. K. Sen • Regularization Weight estimation in Basis Pursuit Inversion using a Bayesian Framework, R. Biswas

and M. K. Sen • Double difference rock-physics inversion for porosity and CO2 saturation at the Cranfield injection

site, Cranfield MS. Russell W. Carter and Kyle T. Spikes • Rock-type model characterization of composition and fabric in the Haynesville Shale, S. Coyle and

K. Spikes • Rock physics modeling to monitor movement of CO2 in Sleipner gas field, North Sea: an ideal CCS

field, R. Ghosh, M. K. Sen, N. Vedanti, and R. Biswas • Case History of Acquisition and Processing of a High Resolution Shallow Water 3D Multi-cable

Seismic Survey in the Gulf of Mexico Transition Zone. T. Hess, T. Meckel, N. Bangs, and R.Tatham

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• Characterization of VTI media with P-SV AVO attributes P. J. Gustie, R. H. Tatham, and K. T. Spikes

• Application of discontinuous Galerkin method in seismic wave propagation: determining effective elastic properties base on rock microstructures H. Liu, K. T. Spikes, and M. K. Sen

• Direct shear wave polarization corrections across multiple offsets and anisotropic layers, J. Maleski and R. H. Tatham

• Seismic sensitivity to variations of rock properties in the productive zone of the Marcellus Shale, WV, S. M. Morshed and R. H. Tatham

• Anisotropic rock-physics modeling for the Haynesville Shale, Q. Ren and K. Spikes • Double plane wave reverse time migration in the frequency domain Z. Zhao, M. K. Sen, P. L. Stoffa • Double plane wave reverse time migration in the time domain Z. Zhao, P. L. Stoffa, and M. K. Sen 2014 AGU Abstracts • Datta, D., and M. K. Sen, 2014, Hybrid optimization methods in full waveform inversion, AGU Fall

meeting, San Francisco. • Sen, M. K., and R. Biswas, 2014, Transdimensional seismic inversion using Hamiltonia Monte-

Carlo approach, AGU Fall meeting, San Francisco. • Agarwal, M., J. Pulliam, M. K. Sen, and H. Gurolla, 2014, Crustal and upper mantle structure of

Texas-Gulf of Mexico from surface wave inversion and receiver function migration, AGU Fall meeting, San Francisco.

• Ojha, M., M. K. Sen, and K. Sain, 2014, Imaging of gas hydrate bearing sedminents by full waveform inversion of multi-channel seismic data from Krishna-Godavari basin, India, AGU Fall meeting, San Francisco.

• Ghosh, R., M. K. Sen, P. Mandal, J. Pulliam and M. Agarwal, 2014, Seismic velocity assessment in the Kartchch region India, from multiple waveform functionals, AGU Fall meeting, San Francisco.

• Datta, D., and M. K. Sen, 2014, Hybrid optimization methods in full waveform inversion, SEG-AGU workshop on full wavefield inversion, Vancouver, Canada (July 2014).

Selected Recent EDGER Papers

1. Carter, R. W., K. T. Spikes, and T. Hess, 2014, Inversion of multicomponent 3D vertical seismic profile data for porosity and CO2 saturation at the Cranfield injection site, Cranfield, MS: Interpretation, 2, SE77–SE89, DOI: 10.1190/INT-2013-0147.1.

2. Carter, R. W., and K. T. Spikes, 2013, Sensitivity analysis of Tuscaloosa Sandstones to CO2 saturation, Cranfield Field, Cranfield, MS: International Journal of Greenhouse Gas Control, doi: 10.1016/j.ijggc.2013.01.006

3. Jiang, M. and K. T. Spikes, 2013, Characterizing the reservoir properties of the Haynesville Shale using rock-physics modeling and grid searching: Geophysical Journal International, 195, 315–239, DOI: 10.1093/gji/ggt250.

4. Liu, Y., and M. K. Sen, 2013, Time-space domain dispersion-relation-based finite-difference method with arbitrary even-order accuracy for the 2D acoustic wave equation, Journal of Computational Physics, 232(1), 327-345.

5. Mandal, B., M. K. Sen, and V. VijayaRao, 2013, New seismic images of the central Indian suture zone and their tectonic interpretation, Tectonics, 32, doi:10.1002/tect.20055.

6. Moyano, B., T. A. Johansen, R. Agersborg, and K. T. Spikes, 2014, Diagnostics of seismic time lapse effects of sandstones based on laboratory data: Geophysics, 70, 5, D275–D287, DOI: 10.1190/GEO2013-0167.1.

7. Prasad, A. S. S. R. S, K. Sain, and M. K. Sen, 2014, Imaging sub-basalt mesozoics along Jakhau-Mandvi and Mandvi-Mundra profiles in Kutch sedimentary basin from seismic and gravity modeling, Geohorizons, 51-56.

8. Satyavani, N., M. K. Sen, M. Ojha, and K. Sain, 2013, Azimuthal anisotropy in OBS observations in Mahanadi offshore, India, Interpretation, 1(2), T187-T198.

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9. Sen, M. K., and L. N. Frazer, 2013, Multi-fold phase space path integral synthetic seismograms, Society of Exploration Geophysicists (SEG) reprint volume on Seismic Diffraction: Modeling, Observation, and Imaging, edited by Michael Pelissier, Tijmen Jan Moser, Kamill Klem-Musatov, and Henning Hoeber.

10. Sen, M. K., and P. L. Stoffa, 2013, Global Optimization Methods is Geophysical Inversion, Second Edition, Cambridge University Press, In Press.

11. Spikes, K. T., 2014, Error estimates of elastic components in stress-dependent VTI media: Journal of Applied Geophysics, 108, 110–123, 10.1016/j.jappgeo.2014.06.015.

12. Spikes, K. T. and M. Jiang, 2013, Rock physics relationships between elastic and reservoir properties in the Haynesville Shale, in U. Hammes and J. Gale, eds., Geology of the Haynesville Gas Shale in East Texas and West Louisiana, U.S.A.: AAPG Memoir 105, 189–203, DOI:10.1306/13441850M1053603.

13. Tao, Y., and M. K. Sen, 2013, Seismic interferometry in plane wave domain, Geophysics, 78(4), Q35-Q44.

14. Tao, Y., and M. K. Sen, 2013, Suppressing non-Gaussian noises with scaled receiver wavefield for reverse-time migration: comparison of different approaches, Geophys. Prospecting, 61, 761-770, #2687.

15. Tao, Y., and M. K. Sen, 2013, On a plane-wave based cross correlation-type seismic interferometry, Geophysics, 78, Q35-Q44, #2686.

16. Tao, Y., and M. K. Sen, R. Zhang, and K. T. Spikes, 2013, A robust stochastic inversion workflow for time-lapse data: hybrid starting model and double difference inversion, Journal of Geophysics and Engineering, 10, doi:10.1088/1742-2132/10/3/035011.

17. Zhang, R, X. Song, S. Fomel, M. K. Sen, S. Srinivasan, 2014, Time‐lapse pre‐stack seismic data registration and inversion for CO2 sequestration study at Cranfield, Geophysical Prospecting, doi: 10.1111/1365-2478.12114.

18. Zhang, R., M. K. Sen and S. Srinivasan, 2014, Time-lapse pre-stack seismic inversion with thin bed resolution for monitoring CO2 sequestration from Carnfield, Mississippi, International Journal of Greenhouse Gas Control, 20, 223-229.

19. Zhang, R., S. Song, S. Fomel, M. K. Sen and S. Srinivasan, 2013, Time-lapse seismic data registration and inversion for CO2 sequestration study at Cranfield, Geophysics, 78(6), B329-B338.

20. Zhang, R., M. K. Sen, and S. Srinivasan, 2013, Pre-stack basis pursuit inversion, Geophysics, VOL. 78, 1, P. R1–R11.

Current EDGER Forum Members

Contact Information

Margo C. Grace, Forum Coordinator, tel: (512) 232-1920, fax: (512) 471-0959, margo@jsg.utexas.edu