Westerngeco L.l.p.

Other

Geco Technology B.v.

Ran Bachrach

Konstantin Osypov

Madhumita Sengupta

Nader Dutta

Colin Michael Sayers

Jianchun Dai

Ling Duan

Anubrati Mukherjee

Sherman Yang

Arturo Ramirez

A method for updating a velocity model of a subsurface of the earth is described herein. A tomographic update to the velocity model of the subsurface may be performed to generate a tomographic velocity model update. A geomechanical velocity model update of the subsurface may be calculated. The geomechanical velocity model update may be combined with the tomographic velocity model update.

Combining geomechanical velocity modeling and tomographic update for velocity model building

Prior information describing a distribution of values of a parameter relating to physical characteristic of a target structure is received. Acquired survey data of the target structure is received. Using a probabilistic technique, the prior information and the survey data is assimilated to produce an estimated property of the target structure.

Estimating a property by assimilating prior information and survey data

Rock physics guided migration is disclosed to enhance subsurface three-dimensional geologic formation evaluation. In one embodiment, a geologic interpretation is generated based on a seismic data volume. Sets of compaction and acoustic formation factor curves are generated, and these are combined into a set of velocity-relationship curves. A pore pressure is derived and used to establish a pore pressure state. A rock physics template is then generated utilizing the derived information. This rock physics template can be used to refine geologic formation evaluation with any suitable form of migration technique.

Methods and devices for transformation of collected data for improved visualization capability

A method and apparatus for constructing a velocity model of a subsurface of the earth, is disclosed herein. Seismic data may be received. A first velocity model of the subsurface may be constructed using the seismic data. The subsurface may have one or more salt bodies. A second velocity model of the subsurface without the salt bodies may be constructed using the seismic data. A set of attributes induced by the salt bodies may be determined based on the first velocity model and the second velocity model. A stiffness tensor change between the first velocity model and the second velocity model may be calculated based on the set of attributes induced by the salt bodies. The first velocity model may be updated based on the stiffness tensor change.

Constructing velocity models near salt bodies

A method for processing seismic data. The method includes performing a plurality of stochastic simulations for one or more rock model parameters to generate one or more anisotropic parameters for a subsurface area of the earth. The method then derives one or more joint multi-dimensional probability density functions for the anisotropic parameters. Using the joint multi-dimensional probability density functions and measured well log data, the method computes one or more posterior probability density functions. The method then includes deriving one or more anisotropic profiles from the posterior probability density functions and generating a seismic image from the anisotropic profiles.

Estimating anisotropic parameters

A method and apparatus for estimating velocity in a subsurface region. Seismic data for a subsurface region may be received. One or more attributes for the seismic data may be calculated. A posterior distribution may be generated. The posterior distribution may represent one or more probabilities of one or more velocities for the attributes. A velocity with uncertainty may be determined for the subsurface region based on the posterior distribution. A pore pressure with uncertainty may be determined based on the velocity with uncertainty.

Estimating velocities with uncertainty

Various implementations described herein are directed to estimating stresses and elastic parameters in a formation based on seismic data. In one implementation, wide azimuth seismic data may be used to derive anisotropic elastic parameters. Furthermore, stresses may be calculated using a geomechanical earth model, followed by deriving anisotropic elastic parameters based on the calculated stresses. The anisotropic elastic parameters derived from the wide azimuth seismic data may then be used to modify the geomechanical earth model to improve the prediction of drilling parameters.

Estimation of stress and elastic parameters

A method and apparatus for estimating a porosity and a saturation in a subsurface reservoir. The method includes determining a plurality of mathematical relationships relating a plurality of fundamental physical parameters that govern elastic wave propagation in the subsurface reservoir to the porosity and the saturation in the subsurface reservoir, forward modeling a plurality of seismic attributes using the mathematical relationships to derive a plurality of conditional probability density functions for the seismic attributes, applying a Bayesian inversion to the conditional probability density functions for the seismic attributes to derive a joint probability density function for the porosity and the saturation in the subsurface reservoir, and integrating the joint probability density function for the porosity and the saturation to derive a probability density function for the porosity and a probability density function for the saturation.

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Houston, TX, United States of America

Ran Bachrach