Inferring the statistical distribution of velocity heterogeneities by statistical traveltime tomography
| Autor: | Tapan Mukerji, Yann Samuelides, Mustafa Touati, Bertrand Iooss, David Geraets, Alain Galli |
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| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | GEOPHYSICS. 68:1714-1730 |
| ISSN: | 1942-2156 0016-8033 |
| DOI: | 10.1190/1.1620645 |
| Popis: | Understanding the internal heterogeneities of reservoirs is one of the key issues in better recovery and efficient reservoir management. Seismic data are widely used to map subsurface heterogeneities. These heterogeneities can include variations in wave velocity and rock density, which can be used to interpret variations in reservoir properties such as porosity, lithofacies, and fluids. This paper describes a statistical tomography method to infer the spatial statistics of subsurface velocity heterogeneities from seismic data. We consider an acoustic wave propagating in a medium represented as a single macromodel superimposed on statistically stationary random velocity perturbations. While the macromodel is retrieved by classical seismic methods, the picked traveltimes and their fluctuations are used to estimate the covariance function of the spatially varying velocity perturbations. We present a formulation based on ray‐theoretical results and describe two algorithms: one using the prestack traveltimes and the other using the stacking velocities. The methods are tested with synthetic seismic reflection data in an idealized medium (with a Gaussian spatial covariance) and with synthetic transmission data in a more geologically realistic medium. Then, the two algorithms are applied on real data. The estimates of the spatial statistics obtained from inverting the traveltime statistics match reasonably well with the true parameters of the heterogeneous media. |
| Databáze: | OpenAIRE |
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