Exxonmobil Upstream Research Company

Ganglin Chen

Dominique Gillard

Max Deffenbaugh

Matthias Imhof

Shiyu Xu

Limin Song

Pavel Dimitrov

Weichang Li

Partha Sarathi Routh

Enru Liu

John Henry Dunsmuir

Dezhi Chu

David H Johnston

Musa Maharramov

Xiaoxia Xu

Michael A Payne

Provided is a method for determining convergence in full wavefield inversion (FWI) of 4D seismic (time-lapse seismic: 3D seismic surveys acquired at different times with the first survey termed as the baseline and subsequent surveys termed as monitors). FWI applied to field seismic data includes iteratively solving for subsurface property models and model difference between monitor and baseline. Iteration occurs until the model difference is sufficiently converged. Rather than determining convergence by examining an entire subsurface region of the models and/or the model difference, subparts of the subsurface region models and/or the model difference are examined in order to determine convergence. For example, different regions behave differently, include the target reservoir region (where hydrocarbon is present) and the background region that is outside the target reservoir region. Thus, transforming the subregions of the models and/or the model difference and analyzing the transformations may indicate convergence of the overall model difference.

Method for determining convergence in full wavefield inversion of 4D seismic data

A hydrocarbon exploration method for determining subsurface properties from geophysical survey data. Rock physics trends are identified and for each trend a rock physics model is determined that relates the subsurface property to geophysical properties (). The uncertainty in the rock physics trends is also estimated (). A geophysical forward model is selected (), and its uncertainty is estimated (). These quantities are used in an optimization process () resulting in an estimate of the subsurface property and its uncertainty.

Method for estimating subsurface properties from geophysical survey data using physics-based inversion

A hydrocarbon exploration method is disclosed for developing a model of at least one effective material property of a subsurface reservoir as a function of the composition and structure of the reservoir rock. In one embodiment, the method comprises: obtaining a 3D image () of a rock sample characteristic of a reservoir of interest (); segmenting the 3D image into compositional classes () based on similarities in mineralogy, structure and spatial distribution; selecting a model () that relates an effective material property of interest to the volume fractions of each compositional class; and determining the parameters of the model (). The model may be used to assess the commercial potential of the subsurface reservoir ().

Method for determining the properties of hydrocarbon reservoirs from geophysical data

A method including analyzing seismic data relating to a producing hydrocarbon reservoir is disclosed. The seismic data includes first and second sets of seismic data obtained at different times. An interval composed substantially of hard rock is identified in the hydrocarbon reservoir. 4D seismic attributes for the region are calculated. Rock physics relationships are applied to seismic data related to the interval according to the permeability associated therewith. A fluid saturation change or a pressure change of the interval is inferred based on outputs of the first or second sets of rock physics relationships and the calculated 4D attributes for the interval. The inferred fluid saturation change or pressure change of the interval is outputted.

Method for determining the fluid/pressure distribution of hydrocarbon reservoirs from 4D seismic data

A computer-implemented method is provided for searching and analyzing a seismic data volume acquired in a seismic survey to determine potential for hydrocarbon accumulations in an associated subsurface region. Surfaces describing the seismic data volume are obtained. The surfaces are enumerated. At least one enumerated surface is selected. The at least one selected surface is augmented when the selected surface does not substantially cover an area associated with the seismic data volume. The augmenting is performed until all selected surfaces substantially cover the area. The at least one selected surface is displayed, with geologic or geophysical data associated therewith, for visual inspection or interpretation, or saving digital representations thereof to computer memory or data storage.

Method for geophysical and geological interpretation of seismic volumes using chronological panning

Method for transforming geologic data relating to a subsurface region between a geophysical depth domain and a geologic age domain. A set of topologically consistent surfaces () is obtained that correspond to seismic data (). The surfaces are enumerated in the depth domain. An age is assigned to each surface in the depth domain (). The age corresponds to an estimated time of deposition of the respective surface. An age mapping volume is generated (). An extent of the age domain is chosen. A depth mapping volume is generated (). Both the age mapping volume and the depth mapping volume are used to transform geophysical, geologic, or engineering data or interpretations () between the depth domain and the age domain () and vice versa (). The geophysical, geologic, or engineering data or interpretations transformed by at least one of the age or depth mapping volume are outputted.

Method for geophysical and geological interpretation of seismic volumes in the domains of depth, time, and age

Method for modeling anisotropic elastic properties of a subsurface region comprising mixed fractured rocks and other geological bodies. P-wave and fast and slow S-wave logs are obtained, and an anisotropic rock physics model of the subsurface region is developed (). P- and fast and slow S-wave logs at the well direction are calculated using a rock physics model capable of handling fractures and other geological factors (). Calculated values are compared to measured values in an iterative model updating process (). An upscaled ID model is developed by averaging elastic properties in each layer using an upscaling theory capable of handling at least orthorhombic anisotropy (). The ID model may be used to generate synthetic seismic response for well ties or AVO modeling (). Further, a method is disclosed for estimating anisotropy parameters from P- and fast/slow S-wave logs from one or more deviated wells.

Growing community of inventors

Houston, TX, United States of America

Ganglin Chen