Conocophillips Company

Exxonmobil Upstream Research Company

Shearwater Geoservices Software Inc.

Robert G Keys

Joel D Brewer

Charles Clinton Mosher

Chengbo Li

Sam T Kaplan

Peter M Eick

Rebecca L Saltzer

Thomas James Wheeler

Baishali Roy

Dana M Jurick

Shiyu Xu

Christopher J Finn

Samik Sil

Douglas J Foster

Jane W Mutoru

Mark J Fissell

A method of characterizing a subterranean formation using a plurality of seismic acquisitions includes obtaining a first seismic acquisition of the subterranean formation, wherein the first seismic acquisition is a baseline survey. Injecting a gas fluid into the subterranean formation, wherein the gas fluid at least partially fills a portion of a fracture network of the subterranean formation. Obtaining a second seismic acquisition of the subterranean formation. Calculating a time-lapse difference in the plurality of seismic acquisitions.

4D seismic as a method for characterizing fracture network and fluid distribution in unconventional reservoir

A method for 2D seismic data acquisition includes determining source-point seismic survey positions for a combined deep profile seismic data acquisition with a shallow profile seismic data acquisition wherein the source-point positions are based on non-uniform optimal sampling. A seismic data set is acquired with a first set of air-guns optimized for a deep-data seismic profile and the data set is acquired with a second set of air-guns optimized for a shallow-data seismic profile. The data are de-blended to obtain a deep 2D seismic dataset and a shallow 2D seismic dataset.

Use NUOS technology to acquire optimized 2D data

Use nuos technology to acquire optimized 2D data

Computer-implemented method for determining optimal sampling grid during seismic data reconstruction includes: a) constructing an optimization model, via a computing processor, given by min&#x2225;Su&#x2225;s.t. &#x2225;Ru&#x2212;b&#x2225;&#x2266;&#x3c3; wherein S is a discrete transform matrix, b is seismic data on an observed grid, u is seismic data on a reconstruction grid, and matrix R is a sampling operator; b) defining mutual coherence as wherein C is a constant, S is a cardinality of Su, m is proportional to number of seismic traces on the observed grid, and n is proportional to number of seismic traces on the reconstruction grid; c) deriving a mutual coherence proxy, wherein the mutual coherence proxy is a proxy for mutual coherence when S is over-complete and wherein the mutual coherence proxy is exactly the mutual coherence when S is a Fourier transform; and d) determining a sample grid r=arg min&#x3bc;(r).

Compressive sensing

Methods for fracture characterization of unconventional formations are provided. Synthetic seismic fracture responses can be generated based on the derived fracture parameters. The synthetic seismic fracture responses may then be used to derive optimum seismic data acquisition geometry for fracture characterization. These methods of determining the seismic data acquisition geometry are advantageous over conventional methods in that these methods are more reliable and cheaper than existing empirical methods, particularly as applied to fractured unconventional formations. Moreover, these methods allow fracture parameters to be derived from limited but common well log data. Certain embodiments additionally contemplate determining the presence of gas filled fractures. These characterizations and evaluations of unconventional formations are useful for, among other things, determining optimal producing intervals and optimal drilling locations. These methods can eliminate the use of costly image logs and core data. These methods ultimately translate to more efficient seismic imaging and more optimal hydrocarbon production.

Methods for seismic fracture parameter estimation and gas filled fracture identification from vertical well log data

Method for determining best and worst cases for values of model parameters such as porosity and shale volume fraction generated by non-unique matrix inversion of physical data such as seismic reflection amplitudes. The matrix is diagonalized, and then orthonormal basis vectors associated with insignificant diagonal elements are used to generate upper and lower bounds on the solution. Best and worst case solutions are determined as linear combinations of the null basis vectors, where the expansion coefficients are determined by making a best fit to the upper and lower bounds.

Method for predicting the best and worst in a set of non-unique solutions

Method for constructing an integrated rock physics model that simulates both shale anisotropy and stress-induced anisotropy of clastic rocks. In the model, the total pore volume is divided into three parts according to the estimated shale volume and effective stress: (1) clay-related pores, (2) sand-related pores, and (3) microcracks (mainly in the sand component). The pore space is then partitioned into the clay-related and sand-related pores using a scheme first disclosed by Xu and White in 1995. The model simulates shale anisotropy via the preferred orientation of clay-related pores and stress-induced anisotropy via the preferred orientation of microcracks, which is controlled by the differential stresses. Laboratory measurements or well logs are needed to establish a relationship between crack density and the effective stress.

Integrated anisotropic rock physics model

Growing community of inventors

Houston, TX, United States of America

Robert G Keys