US 6,018,497 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 which simulates properties of an earth formation located near one or more wellbores. An interpretation workstation includes at least two software programs stored therein: a first program called "Petragrid" and a second simulation program which is responsive to output data produced from the first "Petragrid" program for generating a set of simulation results. The set of simulation results are displayed on a workstation display monitor of the workstation. The first Petragrid software program will: receive well log and seismic data which indicates the location of each layer of a formation near a wellbore, and then grid each layer of the formation, the grid being comprised of a plurality of cells. The first Petragrid software will then generate more accurate data associated with each cell, such as the transmissibility of well fluid through each cell. The more accurate data for each cell originating from the first Petragrid software will be transmitted to the second simulation program. The second simulation program will respond to the more accurate data for each cell of the grid from the Petragrid software by generating a set of more accurate simulation results for each cell of the grid. The second simulation program will overlay the more accurate simulation result for each cell onto each of the corresponding cells of the grid which is being generated and displayed on the workstation display by the Petragrid software. As a result, the workstation will display each layer of the earth formation where each layer is gridded with a plurality of cells, and each cell has its own particular color which corresponds in numerical value to the particular more accurate simulation result (e.g., pressure or saturation) that corresponds to that cell.

Claims29

Dependent claims

An apparatus responsive to a set of seismic data and a set of well log data for 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, comprising:

output data generating means operatively responsive to the set of seismic data and the set of well log data for generating output data, said output data including a plurality of values, each 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:
##EQU24## 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;
display means for displaying said gridded earth formation comprised of said plurality of grid cells;
and
simulator means operatively connected to said display means and responsive to said output data from said output data generating means for generating said plurality of simulation results associated, respectively, with said plurality of grid cells, each of said plurality of simulation results being overlayed over a grid cell of said plurality of grid cells on said display means for displaying a simulation result for each of said plurality of grid cells of said gridded earth formation.

2 more elements

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

means for building a boundary;
means for distributing a plurality of points inside said boundary;
means for 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;
means for 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;
means for 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;
means for generating an un-structured grid in response to the means for grouping comprised of a plurality of grid cells;
means for calculating cell property information for each of said plurality of grid cells;
means for 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;
and
display mans for displaying said plurality of grid cells and the respective plurality of simulation results.

7 more elements

Apparatus responsive to input data for generating more accurate earth formation grid cell property information for use by a simulator, said simulator displaying more accurate simulation results of said earth formation, comprising:

means responsive to said input data for defining an un-structured grid data structure, said un-structured grid data structure comprising a first plurality of grid cells;
cell property calculator means responsive to said first plurality of grid cells of said un-structured grid for calculating a particular property associated with each pair 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;
data exporter means responsive to said un-structured grid data structure and the particular properties associated therewith for mapping the un-structured grid of said un-structured grid data structure into a structured grid thereby producing an output data structure comprised of said structured grid having a second plurality of grid cells;
simulator means responsive to said output data structure for generating a set of simulation results;
and
display means responsive to said set of simulation results for displaying said simulation results, said simulation results representing said more accurate simulation results of said earth formation.

3 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

Claims29