Pre-Stack Seismic Inversion and Amplitude Versus Angle Modeling Reduces the Risk in Hydrocarbon Prospect Evaluation

Surender Singh, D. K. Gupta, Sanjeev Rajput

Abstract


Pre-Stack seismic inversion and Amplitude versus Angle (AVA) techniques were used in for direct hydrocarbon identification (DHI) and to understand better the risk during hydrocarbon prospecting. In order to understand and predict the seismic response for different fluid type and lithologies pre-stack seismic inversion and AVA modeling based on existing well logs information were performed. An optimized seismic inversion workflow that includes conditioning of seismic data followed by seismic petrophysics and rock physics modeling in combination with fluid substituted logs was used to predict the seismic response for different fluid types. Inverted rock properties of a wedge model were then correlated with seismic response for DHI. Another hydrocarbon prospect was studied based on AVA modeling response. AVA effects on angle gathers provide basic information on the lithology and pore fill contents of the rocks under investigation. To perform the AVA modeling, a series of forward models in association with rock physics-modeled fluid-substituted logs have been developed and associated seismic responses for different pore fluids and rock types studied. The results reveal that synthetic seismic responses together with the AVA analysis show changes for different lithologies. AVA attributes analysis show trends in generated synthetic seismic responses for different fluid-substituted and porosity logs. Reservoir modeling and fluid substitution increases understanding of the observed seismic response. It ultimately leads to a better reservoir prediction with delineation of sweet spots and improved volumetric prognosis. Assessing the effect of fluid-substituted logs for different lithologies and associated AVA seismic response can improve the prediction in reservoir characterization. Truly integrated studies of seismic, geology and well data will reduce the drilling and development risks even further.
Key Words: Pre-stack seismic inversion; Wedge model; Amplitude versus angle (AVA); Fluid substitution; Intercept (I); Gradient (G); Rock physics; Derisking and forward modeling


Keywords


Pre-stack seismic inversion; Wedge model; Amplitude versus angle (AVA); Fluid substitution; Intercept (I); Gradient (G); Rock physics; Derisking and forward modeling

Full Text:

PDF

References


[1]       Latimer, R. B., Davison, R., & van Riel, P. (2000). An interpreter’s guide to understanding and working with seismic derived acoustic impedance data. Leading Edge, 242-256.

[2]       Castagna, J. P., & Swan, H. W. (1997). Principles of AVO crossplotting. Society of Exploration Geophysicists, 17, 337-342.

[3]       Castagna, J. P., Swan, H. W., & Foster, D. J. (1998). Framework for AVO gradient and intercept interpretation, geophysics. Society of Exploration Geophysicists, 63, 948-956.

[4]       Bortfeld, R. (1961). Approximations to the reflection and transmission coefficients of plane longitudinal and transverse waves. Geophysical Prospecting, 9(4), 485-503.

[5]       Aki, K., & Richards, P. G. (1980). Quantitative seismology: Theory and methods. San Francisco: W.H. Freeman and Co.

[6]       Shuey, R. T. (1985). A simplification of the Zeoppritz equations. Geophysics, 50, 609-614.

[7]       Mavko, G., Mukerji, T., & Dvorkin, J. (1998). The rock physics handbook: Tools for seismic analysis in porous media. England: Cambridge University Press.

[8]       Smith, T. M., Sondergeld, C. H., & Rai, C. S. (2003). Gassmann fluid substitutions: A tutorial. Geophysics, 68, 430-440.

[9]       Ross, C. P. (2000). Effective AVO crossplot modeling: A tutorial, Geophysics. Society of Exploration Geophysicists, 65, 700-711.

[10]    Russell, B. R., Hedlin, K., Hilterman, F. J., & Lines, L. R. (2003). Fluid-property discrimination with AVO: A Biot-Gassmann perspective. Geophysics, 68, 29-39.

[11]    Basham, S. K., Kumar, A., Borgohain, J. K., Shaw, R., Gupta, M., & Singh, S. (2012). Rock physics modeling and simultaneous inversion for heavy oil reservoirs: A case study in western India. First Break, 30, 69-75.

[12]    Greenberg, M. L., & Castagna, J. P. (1992). Shear-wave velocity estimation in porous rocks: Theoretical formulation, preliminary verification and application. Geophysical Prospecting, 40, 195-209.

[13]    Gassmann, F. (1951). On elasticity of porous media [Description of form].  Retrieved from http://sepwww.stanford.edu/sep/berryman/PS/gassmann.pdf

[14]    Veeken, P., & Rauch-Davies, M. (2006). AVO attribute analysis and seismic reservoir characterization. First Break, 24, 41-52.

[15]    Batzle, M. L., & Wang, Z. (1992). Seismic properties of pore fluids. Geophysics, 64, 1396-1408.

[16]    Bortfeld, R. (1961). Approximations to the reflection and transmission coefficients of plane longitudinal and transverse waves. Geophysical Prospecting, 9(4), 485-503.

[17]    Rajput, S., Thakur, N. K., & Rao, P. P. (2013). Linking methane seepage to fluid flow mechanism: Evidence from AVO characteristics of bottom Simulating reflectors. Advances in Petroleum Exploration and Development, 5(1), 1-13.

[18]    Rutherford, S. R., & Williams, R. H. (1989). Amplitude-versus-offset variations in gas sands. Society of Exploration Geophysicists, 54, 680-688.

[19]    Veeken, P., & Rauch-Davies, M. (2006). AVO attribute analysis and seismic reservoir characterization. First Break, 24, 41-52.




DOI: http://dx.doi.org/10.3968%2F5170

Refbacks

  • There are currently no refbacks.


Reminder

If you have already registered in Journal A and plan to submit article(s) to Journal B, please click the CATEGORIES, or JOURNALS A-Z on the right side of the "HOME".

We only use three mailboxes as follows to deal with issues about paper acceptance, payment and submission of electronic versions of our journals to databases:
caooc@hotmail.com; aped@cscanada.net; aped@cscanada.org

Copyright © 2010 Canadian Research & Development Centre of Sciences and Cultures
Address: 730, 77e AV, Laval, Quebec, H7V 4A8, Canada

Telephone: 1-514-558 6138
Http://www.cscanada.net
Http://www.cscanada.org
E-mail:office@cscanada.net  office@cscanada.org