US 6,078,869 A · Method and apparatus for generating more accurate earth formation grid cell property information for use by a simulator to display more accurate simulation results of the formation near a wellbore

Abstract

A Petragrid method and apparatus generates grid cell property information that is adapted for use by a computer simulation apparatus. An interpretation workstation includes at least two software programs stored therein: a first program called "Petragrid" and a second simulation program for generating a set of simulation results for display. The first Petragrid software program will: receive well log and seismic data which indicates each layer of a formation, grid each layer of the formation where the grid is comprised of a plurality of cells, and generate more accurate data associated with each grid cell, such as the transmissibility. The more accurate data for each cell will be transmitted to the second simulation program which will respond by generating a set of more accurate simulation results for each cell of the grid, and overlaying the more accurate simulation result for each cell onto each of the corresponding cells of the grid being displayed on the workstation display by the Petragrid software. The workstation will display each layer of the formation where each layer is gridded, and each grid cell has its own color corresponding in numerical value to a more accurate simulation result (e.g., pressure or saturation) that corresponds to that cell.

Claims51

Dependent claims

A method of generating more accurate earth formation grid cell property information adapted for use by a simulator for displaying more accurate simulation results of the formation near a wellbore, comprising the steps of:

(a) building a boundary;
(b) distributing a plurality of points inside said boundary;
(c) connecting together said plurality of points inside said boundary such that a plurality of triangles are formed in 2D space or a plurality of tetrahedra are formed in 3D space;
(d) creating an aggregation map comprised of a list of certain ones of said plurality of triangles or certain ones of said plurality of tetrahedra which should be grouped together to form a polygonal shape, said certain ones of said plurality of triangles and said certain ones of said plurality of tetrahedra having nodes which are nearest neighbors of a structured distribution of points and having circumcenters which are clustered closely together;
(e) grouping together inside said boundary said certain ones of said plurality of triangles or said certain ones of said plurality of tetrahedra in response to said aggregation map;
(f) generating an unstructured grid in response to the grouping step comprised of a plurality of grid cells;
(g) calculating cell property information for each of said plurality of grid cells;
and
(h) generating output data which includes said cell property information for said each of said plurality of grid cells, said output data being adapted for use by said simulator, said simulator generating a plurality of said simulation results associated, respectively, with said plurality of grid cells of said un-structured grid in response to said output data, a display displaying said plurality of grid cells and the respective plurality of simulation results.

6 more elements

A device, comprising:

a pre-recorded means readable by a computer for storing instructions, said instructions, when executed by said computer, conducting a process comprising the steps of:
(a) building a boundary;
(b) distributing a plurality of points inside said boundary;
(c) connecting together said plurality of points inside said boundary such that a plurality of triangles are formed in 2D space or a plurality of tetrahedra are formed in 3D space;
(d) creating an aggregation map comprised of a list of certain ones of said plurality of triangles or certain ones of said plurality of tetrahedra which should be grouped together to form a polygonal shape, said certain ones of said plurality of triangles and said certain ones of said plurality of tetrahedra having nodes which are nearest neighbors of a structured distribution of points and having circumcenters which are clustered closely together;
(e) grouping together inside said boundary said certain ones of said plurality of triangles or said certain ones of said plurality of tetrahedra in response to said aggregation map;
(f) generating an un-structured grid in response to the grouping step comprised of a plurality of grid cells;
(g) calculating cell property information for each of said plurality of grid cells;
and
(h) generating output data which includes said cell property information for said each of said plurality of grid cells,
said output data being adapted for use by said simulator, said simulator generating a plurality of said simulation results associated, respectively, with said plurality of grid cells of said un-structured grid in response to said output data, a display displaying said plurality of grid cells and the respective plurality of simulation results.

8 more elements

A method of displaying a gridded earth formation comprised of a plurality of grid cells located near a wellbore and a plurality of simulation results associated, respectively, with said plurality of cells in response to a set of seismic data and a set of well log data, comprising the steps of:

(a) generating output data in response to the set of seismic data and the set of well log data, said output data including a plurality of values, at least some of said plurality of values being indicative of a transmissibility between a pair of said plurality of cells, said transmissibility being determined from the following equation:
##EQU25## and a=area vector of the interface, K.sub.i =permeability tensor of cell i adjusted by net to gross, r.sub.i =vector from centre of cell i to the interface along the line of centers, C.sub.D =Darcy constant, and NTG=net to gross thickness ratio;
(b) displaying said gridded earth formation comprised of said plurality of grid cells;
and
(c) generating said plurality of simulation results associated, respectively, with said plurality of grid cells displayed in response to the displaying step in response to said output data, each of said plurality of simulation results being overlayed over a grid cell of said plurality of grid cells for displaying a simulation result for each of said plurality of grid cells of said gridded earth formation.

2 more elements

A method for generating more accurate earth formation grid cell property information for use by a simulator in response to input data, said simulator displaying more accurate simulation results of said earth formation, comprising the steps of:

(a) defining an un-structured grid data structure in response to said input data, said un-structured grid data structure comprising a first plurality of grid cells;
(b) calculating, by a cell property calculator, a particular property associated with each pair of grid cells of said un-structured grid in response to said first plurality of grid cells of said un-structured grid, said particular property representing said more accurate earth formation grid cell property information for use by said simulator;
(c) mapping, by a data exporter, the un-structured grid of said un-structured grid data structure into a structured grid in response to said un-structured grid data structure and the particular properties associated therewith thereby producing an output data structure comprised of said structured grid having a second plurality of grid cells;
(d) generating, by a simulator, a set of simulation results in response to said output data structure;
and
(e) displaying said simulation results, said simulation results representing said more accurate simulation results of said earth formation.

3 more elements

A device, comprising:

a pre-recorded means readable by a computer for storing instructions, said instructions when executed by said computer, conducting a process comprising the steps of:
generating more accurate earth formation grid cell property information for use by a simulator in response to input data, said simulator generating and displaying more accurate simulation results of said earth formation, the step of generating and displaying said more accurate simulation results comprising the steps of:
(a) defining an un-structured grid data structure in response to said input data, said un-structured grid data structure comprising a first plurality of grid cells;
(b) calculating, by a cell property calculator, a particular property associated with each pair of grid cells of said un-structured grid in response to said first plurality of grid cells of said un-structured grid, said particular property representing said more accurate earth formation grid cell property information for use by said simulator;
(c) mapping, by a data exporter, the un-structured grid of said un-structured grid data structure into a structured grid in response to said un-structured grid data structure and the particular properties associated therewith thereby producing an output data structure comprised of said structured grid having a second plurality of grid cells;
(d) generating, by a simulator, a set of simulation results in response to said output data structure;
and
(e) displaying said simulation results, said simulation results representing said more accurate simulation results of said earth formation.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for generating more accurate earth formation grid cell property information for use by a simulator to display more accurate simulation results of the formation near a wellbore

Life of this patent

Method and apparatus for generating more accurate earth formation grid cell property information for use by a simulator to display more accurate simulation results of the formation near a wellbore

Life of this patent

Abstract

Claims51