Method of Digitally Identifying Structural Traps

Patent metadata

Field	Value
Publication number	US-2016377752-A1
Application number	US-201514751253-A
Country	US
Kind code	A1
Filing date	Jun 26, 2015
Priority date	Jun 26, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

Embodiments of methods of identifying structural traps are disclosed herein. Embodiments of the disclosed method use an alternative approach to boundary value problem solvers, based on simple mathematical geometry adapted to the nature of the acquired data. Embodiments of the method rely on digital elevation model type of data (i.e. any given subsurface horizon has only single elevation data values). The disclosed methods allow for a significant algorithm speed-up in identifying structural traps especially when handling large and high density datasets which was heretofore not possible with existing methods.

First claim

What is claimed is:

1 . A method of identifying structural traps comprising:
(a) inputting a seismic dataset into a computer, the seismic dataset representative of a subsurface region of interest, and wherein the seismic dataset comprises at least one or more elevation data points; (b) selecting a horizon from the seismic dataset; (c) determining, using the computer, a plurality of elevation contours from the horizon based on the elevation data points to generate a contour dataset; (d) evaluating, using the computer, the plurality of contours to identify one or more structural traps, wherein the one or more structural traps are identified automatically based upon a computer algorithm which uses the elevation data points to identify and classify the one or more structural traps; (e) displaying on the computer one or more contours which represents an outline of the one or more structural traps; and (f) using the one or more structural traps identified in (d) to locate potential hydrocarbon-bearing regions in the subsurface region of interest.

2 . The method of claim 1 , wherein (b) comprises selecting and inputting a step value for spacing of each contour:

3 . The method of claim 1 , wherein the computer algorithm in (d) executes the following operations:
(i) determining whether each contour is an open contour and discarding all open contours; (ii) identifying one or more outermost contours, each outermost contour enclosing one or more inner contours; and (iii) determining whether each outermost contour is a structural trap based on the one or more inner contours contained within the outermost contour.

4 . The method of claim 4 wherein (iii) comprises classifying each outermost contour as at least one of an anticline, a syncline, a structural trap, or a mixed structure.

5 . The method of claim 4 , if an outermost contour is classified as a mixed structure, further comprising repeating (i) through (iii) for the outermost contour and the inner contours contained within the outermost contour.

6 . The method of claim 1 , if a contour abuts a fault, wherein (c) further comprises propagating the contour along the fault.

7 . The method of claim 1 , further comprising repeating (b) through (f) for different horizons in the seismic dataset.

8 . The method of claim 1 wherein the structural traps comprises a three way trap, a four way trap, or combinations thereof.

9 . A computer system, comprising:
an interface for receiving a plurality of seismic input volumes, the seismic input volumes comprising a plurality of seismic traces and one or more horizons; a memory resource; input and output functions for presenting and receiving communication signals to and from a human user; one or more central processing units for executing program instructions; and program memory, coupled to the central processing unit, for storing a computer program including program instructions that, when executed by the one or more central processing units, cause the computer system to perform a plurality of operations comprising: (a) receiving a seismic dataset, the seismic dataset representative of a subsurface region of interest, and wherein the seismic dataset comprises at least one or more elevation data points; (b) determining a plurality of elevation contours from a selected horizon based on the elevation data points to generate a contour dataset; (c) evaluating the plurality of contours to identify one or more structural traps, wherein the one or more structural traps are identified automatically based upon a computer algorithm which uses the contour dataset; (d) displaying on the computer one or more contours which represents an outline of the one or more structural traps; and (e) using the one or more structural traps identified in (c) to locate potential regions in the subsurface region of interest which could produce hydrocarbons.

10 . The system of claim 9 , wherein (b) comprises using a step value for spacing of each contour based on a selected step value from a user.

11 . The system of claim 9 , wherein the computer algorithm in (c) executes the following operations:
(i) determining whether each contour is an open contour and discarding all open contours; (ii) identifying one or more outermost contours, each outermost contour enclosing one or more inner contours; and (iii) determining whether each outermost contour is a structural trap based on the one or more inner contours contained within the outermost contour.

12 . The system of claim 11 wherein (iii) comprises classifying each outermost contour as at least one of an anticline, a syncline, a structural trap, or a mixed structure.

13 . The system of claim 11 , if an outermost contour is classified as a mixed structure, further comprising repeating (i) through (iii) for the outermost contour and the inner contours contained within the outermost contour.

14 . The system of claim 9 , if a contour abuts a fault, wherein (c) further comprises propagating the contour along the fault.

15 . The system of claim 9 , further comprising repeating (b) through (d) for different horizons in the seismic dataset.

16 . The system of claim 9 wherein the structural traps comprises a three way trap, a four way trap, or combinations thereof.

Assignees

• Cavelius Claude Edward Francois
• Kowalik William S
• Marsh Antony J
• Amiotte Jerome
• Chevron Usa Inc

Inventors

• Cavelius Claude Edward Francois
• Kowalik William S
• Marsh Antony J
• Amiotte Jerome

Classifications

• G01V1/30 Primary

  Analysis (G01V1/50 takes precedence) · CPC title

• G01V2210/64

  Geostructures, e.g. in 3D data cubes · CPC title

• G01V1/34 Primary

  Displaying seismic recordings {or visualisation of seismic data or attributes} · CPC title

• G01V1/302

  in 3D data cubes · CPC title