Exxonmobil Upstream Research Company

Gboyega Ayeni

Anatoly I Baumstein

Yaxun Tang

Sirui Tan

John E Anderson

Partha Sarathi Routh

Thomas A Dickens

Carey M Marcinkovich

Tetyana Vdovina

Jaewoo Park

Peter Traynin

Iterative methods for inversion of seismic data to update a physical property model are disclosed. Such methods may comprise iteratively updating the model until a first predetermined resolution is achieved, using full wavefield inversion of the seismic data up to a first frequency threshold and assuming the seismic data is free of attenuation effects; extracting geobodies from the updated model; obtaining a Q model using the geobodies; and updating the physical property model using an inversion process, wherein the Q model is incorporated into the inversion process. These steps may be repeated until a second predetermined resolution of the physical property model is achieved, wherein the first frequency threshold is progressively increased in each repetition. The Q model may be updated with seismic data at all available frequencies to obtain a full-band Q model; and the physical property model may be updated using full-band migration and the full-band Q model.

Accurate velocity model estimation and imaging in the presence of localized attenuation (Q) anomalies

A method, including: obtaining initial estimates of a plurality of subsurface parameters; obtaining a recorded wavefield decomposed into a plurality of discrete components; performing, with a computer, a cascaded inversion where the initial estimates of the subsurface parameters are individually updated, wherein each of the subsurface parameters are updated using a different discrete component of the recorded wavefield of the plurality of discrete components; and generating, with the computer, updated subsurface models from the cascaded inversion for each of the subsurface parameters.

Estimating multiple subsurface parameters by cascaded inversion of wavefield components

A method for iteratively inverting seismic data to jointly infer a model for at least P-wave velocity and attenuation parameters of the subsurface, the method including: jointly inverting the P-wave velocity and attenuation parameters with an iterative visco-acoustic full wavefield inversion process, wherein the iterative visco-acoustic full wavefield inversion process includes computing a gradient of an objective function, the objective function measuring a misfit between all or part of the seismic data and corresponding model-simulated seismic data; for each of the P-wave velocity and attenuation parameters, computing a search direction in model space from the gradient; determining line search step sizes &#x3b1; and &#x3b2; for the search directions for the P-wave velocity and attenuation parameters, respectively, wherein a ratio of the step sizes is a function of the P-wave velocity parameter; and using the step sizes &#x3b1; and &#x3b2; and the search directions for each of the P-wave velocity and attenuation parameters, computing a new search direction in model space, then performing a line search along the new search direction to arrive at a new step size, and using the new step size and the new search direction to generate an updated model for a current iteration of the iterative visco-acoustic full wavefield inversion process.

Joint full wavefield inversion of P-wave velocity and attenuation using an efficient first order optimization

Method for simultaneously inverting full-wavefield seismic data () for multiple classes of physical property parameters (e.g., velocity and anisotropy) by computing the gradient (), i.e. search direction (), of an objective function for each class of parameters, then applying (preferably exhaustive) first-pass independent line searches to each parameter class to obtain the corresponding step size () along the search direction for each parameter class; then without yet updating the model, using the step sizes to define a relative scaling between gradients of all parameter classes. Next, each scaled search direction is recombined to form a new search direction (), and a new second-pass line search is performed along the new search direction (), and all parameters are simultaneously updated with the resulting step size (). Alternatively to the preceding alternating two-pass embodiment, the model may be updated after each first-pass line search, and no second-pass line search is performed.

Efficient line search methods for multi-parameter full wavefield inversion

Growing community of inventors

Humble, TX, United States of America

Gboyega Ayeni