Method for locally controlling spatial continuity in geologic models
AssigneeExxonMobil Upstream Research Company
InventorsCraig S. Calvert, Tingting Yao, Glen W. Bishop, Yuan Ma
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Abstract
The present invention is a method of generating a geologic model which incorporates a local spatial trend in rock property continuity. Initially, a candidate geologic model is generated by assigning a rock-property value to each block of a model grid. Next, local spectra which characterize the desired local spatial trend in rock property continuity are specified. These local spectra are used to frequency scale the rock-property values of the candidate geologic model. The scaled rock-property values are then combined to generate a scaled geologic model that incorporates the local spatial trend in rock property continuity.
Claims24
A computer-implemented method of generating a geologic model, comprising the steps of:
- (a) assigning a rock-property value, on a block-by-block basis, to each block of a space domain candidate geologic model having a three-dimensional array of blocks;
- (b) assigning, on a block-by-block basis, a local spectrum of said rock-property value to each of at least some of said blocks, each said local spectrum of said rock-property value incorporating a local spatial trend in rock property continuity for each respective block;
- (c) using said local spectra to frequency scale said rock-property value, on a block-by-block basis, at each of said blocks;
- and
- (d) using said scaled rock-property values to generate a scaled space domain geologic model incorporating said local spatial trend in rock property continuity.
A computer-implemented method of generating a geologic model, comprising the steps of:
- (a) assigning a rock-property value, on a block-by-block basis, to each block of a space domain candidate geologic model;
- (b) identifying a trend-attribute related to a trend in spatial continuity;
- (c) defining a trend model that characterizes said trend;
- (d) identifying at least two endmember-trend-attribute values for said trend model,
- (e) generating endmember-local spectra at each block in said model for which endmember-trend-attribute values have been identified;
- (f) calculating endmember-local-amplitude-ratio values for each said endmember-local spectra;
- (g) using said trend model and said endmember-local-amplitude-ratio values to frequency scale said rock-property values, on a block-by-block basis, at each of said blocks;
- and
- (h) using said scaled rock-property values to generate a scaled space domain geologic model incorporating said local spatial trend in rock property continuity.
A computer-implemented method of incorporating a spatial trend in rock property continuity into a geologic model, comprising the steps of:
- (a) generating a space domain candidate geologic model for a rock property;
- (b) specifying a global-amplitude spectrum for said space domain candidate geologic model;
- (c) specifying a local-amplitude spectrum for each block in said space domain candidate geologic model, wherein each said local-amplitude spectrum incorporates, on a block-by-block basis, a desired spatial trend in rock property;
- (d) discretizing said global-amplitude spectrum and said local-amplitude spectrum;
- (e) computing local-amplitude ratios for each said block and each said frequency bin using said global-amplitude spectrum and said local-amplitude spectrum;
- (f) computing local-frequency-components for each said frequency bin and each said block using a global spectrum of said model;
- (g) generating scaled-local-frequency-components for each said frequency bin and each said block by multiplying said local-amplitude-ratio values of each said frequency bin for each said block by the local-frequency-component corresponding to said frequency and said block;
- and
- (h) summing all scaled-local-frequency-components for each said block to generate a space domain representation of said space domain geologic model at each said block which incorporates said desired spatial trend.
A computer-implemented method of incorporating a spatial trend in rock property continuity into a geologic model, comprising the steps of:
- (a) generating a space domain candidate geologic model for said rock property;
- (b) specifying a global-amplitude spectrum for said space domain candidate geologic model;
- (c) identifying one or more attributes that correlate with said spatial trend;
- (d) defining a trend model that defines said spatial trend;
- (e) identifying end-member-trend-attribute values for said trend model;
- (f) specifying endmember-local-amplitude spectra, on a block-by-block basis, for each block in said space domain candidate geologic model corresponding to said endmember-trend-amplitude values;
- (g) discretizing said global-amplitude and said endmember-local-amplitude spectra into frequency bins;
- (h) calculating endmember-local-amplitude ratios for each said bin and each said endmember- local-amplitude spectra;
- (i) assigning a local-amplitude-ratio value to each said bin of each said block;
- (j) computing and discretizing into frequency bins a global spectrum of said space domain candidate geologic model;
- (k) computing local-frequency-components for each said bin and each said block of said space domain candidate geologic model;
- (l) computing scaled-local-frequency-components by multiplying said local-amplitude-ratio values of each said frequency bin for each said block by said local-frequency-component corresponding to said frequency and said block;
- and
- (m) summing all scaled-local-frequency-components for each said block to generate a space domain representation of said space domain geologic model at each said block which incorporates said desired spatial trend.
Dependencies are inferred from the claim text.