Hamdi A Tchelepi

US Patent:

7496488, Feb 24, 2009

Filed:

Nov 23, 2004

Appl. No.:

10/997539

Inventors:

Patrick Jenny - Zurich, CH
Seong Lee - Emeryville CA, US
Hamdi A. Tchelepi - San Mateo CA, US

Assignee:

Schlumberger Technology Company - Houston TX
Chevron U.S.A. Inc. - San Ramon CA
ETH Zurich - Zurich

International Classification:

G06G 7/48
G01V 3/38
G01V 1/38
G01V 1/00

US Classification:

703 10, 702 5, 367 23, 367 56, 367 57

Abstract:

A multi-scale finite-volume (MSFV) method to solve elliptic problems with a plurality of spatial scales arising from single or multi-phase flows in porous media is provided. The method efficiently captures the effects of small scales on a coarse grid, is conservative, and treats tensor permeabilities correctly. The underlying idea is to construct transmissibilities that capture the local properties of a differential operator. This leads to a multi-point discretization scheme for a finite-volume solution algorithm. Transmissibilities for the MSFV method are preferably constructed only once as a preprocessing step and can be computed locally.

US Patent:

7505882, Mar 17, 2009

Filed:

Mar 15, 2006

Appl. No.:

11/377760

Inventors:

Patrick Jenny - Zurich, CH
Hamdi A. Tchelepi - San Mateo CA, US
Seong H. Lee - Emeryville CA, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA

International Classification:

G06F 17/10
G06G 7/48

US Classification:

703 2, 703 10, 702 12

Abstract:

An apparatus and method are provided for solving a non-linear S-shaped function F=ƒ(S) which is representative of a property S in a physical system, such saturation in a reservoir simulation. A Newton iteration (T) is performed on the function ƒ(S) at Sto determine a next iterative value S. It is then determined whether Sis located on the opposite side of the inflection point Sfrom S. If Sis located on the opposite side of the inflection point from S, then Sis set to S, a modified new estimate. The modified new estimate, S, is preferably set to either the inflection point, S, or to an average value between Sand S, i. e. , S=0. 5(S+S). The above steps are repeated until Sis within the predetermined convergence criteria. Also, solution algorithms are described for two-phase and three-phase flow with gravity and capillary pressure.

US Patent:

7516056, Apr 7, 2009

Filed:

Apr 25, 2006

Appl. No.:

11/410622

Inventors:

John Wallis - Houston TX, US
Hamdi A. Tchelepi - San Mateo CA, US
Hui Cao - Sugar Land TX, US

Assignee:

Schlumberger Technology Corporation - Houston TX

International Classification:

G06F 9/455

US Classification:

703 10, 702 11

Abstract:

A method, system and apparatus are disclosed for conducting a reservoir simulation, using a reservoir model of a gridded region of interest. The grid of the region of interest includes one or more types of cells, the type of cell being distinguished by the number of unknown variables representing properties of the cells. The cells share a common variable as an unknown variable. The method includes the steps of identifying different cell types for the grid; constructing an overall matrix for the reservoir model based on the different cell types; at least partially decoupling the common variable from the other unknown variables in the matrix by using a reduction process to yield a reduced matrix; mathematically breaking up the variables in the reduced matrix into k subsets by cell types; applying an overlapping multiplicative Schwartz procedure to the reduced matrix to obtain a preconditioner and using the preconditioner to solve for the unknown variables.

US Patent:

7546229, Jun 9, 2009

Filed:

Nov 22, 2004

Appl. No.:

10/995764

Inventors:

Patrick Jenny - Zurich, CH
Seong Lee - Emeryville CA, US
Hamdi A. Tchelepi - San Mateo CA, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA
Schlumberger Technology Corporation - Houston TX

International Classification:

G06G 7/48

US Classification:

703 10

Abstract:

A multi-scale finite-volume (MSFV) method to solve elliptic problems with a plurality of spatial scales arising from single or multi-phase flows in porous media is provided. Two sets of locally computed basis functions are employed. A first set of basis functions captures the small-scale heterogeneity of the underlying permeability field, and it is computed to construct the effective coarse-scale transmissibilities. A second set of basis functions is required to construct a conservative fine-scale velocity field. The method efficiently captures the effects of small scales on a coarse grid, is conservative, and treats tensor permeabilities correctly. The underlying idea is to construct transmissibilities that capture the local properties of a differential operator. This leads to a multi-point discretization scheme for a finite-volume solution algorithm. Transmissibilities for the MSFV method are preferably constructed only once as a preprocessing step and can be computed locally.

US Patent:

7684967, Mar 23, 2010

Filed:

Jun 14, 2006

Appl. No.:

11/453304

Inventors:

John Wallis - Sugar Land TX, US
Hamdi A. Tchelepi - San Mateo CA, US

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G06G 7/48

US Classification:

703 10, 703 2, 345420, 345629

Abstract:

A method, system, a program storage device and apparatus are disclosed for conducting a reservoir simulation, using a reservoir model of a region of interest, wherein the region of interest has been gridded into cells. Each cell has one or more unknown variable. Each cell has a node. A graph of the nodes is represented by a sparse matrix. The graph is an initially decomposed into a pre-specified number of domains, such that each cell exists in at least one domain. The cells and domains are numbered. Each cell has a key, the key of each cell is the set of domain numbers to which the cell belongs. Each cell has a class, the class of each cell being the number of elements in the cell. The cells are grouped into connectors, each connector being the set of cells that share the same key. Each connector having a connector class, the connector class being the number of elements in the key of the connector. Each connector having only one higher-order neighbor connector is merged with such higher-order neighbor connector.

US Patent:

7765091, Jul 27, 2010

Filed:

Jun 14, 2007

Appl. No.:

11/763109

Inventors:

Seong H. Lee - Emeryville CA, US
Christian Wolfsteiner - Oakland CA, US
Hamdi A. Tchelepi - San Mateo CA, US
Patrick Jenny - Zurich, CH
Ivan Fabrizio Lunati - Zurich, CH

Assignee:

Chevron U.S.A Inc. - San Ramon CA
Schlumberger Technology Corporation - Houston TX
ETH Zurich - Zurich

International Classification:

G06G 7/58

US Classification:

703 10

Abstract:

A multi-scale finite-volume (MSFV) method simulates nonlinear immiscible three-phase compressible flow in the presence of gravity and capillary forces. Consistent with the MSFV framework, flow and transport are treated separately and differently using a fully implicit sequential algorithm. The pressure field is solved using an operator splitting algorithm. The general solution of the pressure is decomposed into an elliptic part, a buoyancy/capillary force dominant part, and an inhomogeneous part with source/sink and accumulation. A MSFV method is used to compute the basis functions of the elliptic component, capturing long range interactions in the pressure field. Direct construction of the velocity field and solution of the transport problem on the primal coarse grid provides flexibility in accommodating physical mechanisms. A MSFV method computes an approximate pressure field, including a solution of a course-scale pressure equation; constructs fine-scale fluxes; and computes a phase-transport equation.

US Patent:

7877246, Jan 25, 2011

Filed:

Sep 21, 2007

Appl. No.:

11/859722

Inventors:

Arthur Regis Catherin Moncorgé - Houston TX, US
Hamdi A. Tchelepi - San Mateo CA, US

Assignee:

Schlumberger Technology Corporation - Houston TX
Total SA - Paris
Chevron U.S.A Inc. - San Ramon CA

International Classification:

G06F 19/00
G06T 17/50
G01V 1/00

US Classification:

703 10, 702 13

Abstract:

The invention relates to a method of performing an oilfield operation of an oilfield having at least one wellsite, each wellsite having a wellbore penetrating a subterranean formation for extracting fluid from an underground reservoir therein. The method includes determining a time-step for simulating the reservoir, the reservoir being represented as a plurality of gridded cells and being modeled as a multi-phase system using a plurality of partial differential equations, calculating a plurality of Courant-Friedrichs-Lewy (CFL) conditions of the reservoir model corresponding to the time-step, the plurality of CFL conditions comprising a temperature CFL condition, a composition CFL condition, and a saturation CFL condition, simulating a first cell of the plurality of gridded cells with an Implicit Pressure, Explicit Saturations (IMPES) system, and simulating a second cell of the plurality of gridded cells with a Fully Implicit Method (FIM) system.

US Patent:

8204726, Jun 19, 2012

Filed:

May 14, 2009

Appl. No.:

12/466171

Inventors:

Seong H. Lee - Berkeley CA, US
Hui Zhou - Stanford CA, US
Hamdi A. Tchelepi - Belmont CA, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA
Schlumberger Technology Corporation - Houston TX

International Classification:

G06G 7/48
G06F 17/10

US Classification:

703 10, 703 2, 702 12

Abstract:

A multi-scale method to efficiently determine the fine-scale saturation arising from multi-phase flow in a subsurface reservoir is disclosed. The method includes providing a simulation model that includes a fine-scale grid defining a plurality of fine-scale cells, and a coarse-scale grid defining a plurality of coarse-scale cells that are aggregates of the fine-scale cells. The coarse-scale cells are partitioned into saturation regions responsive to velocity and/or saturation changes from the saturation front. A fine-scale saturation is determined for each region and the saturation regions are assembled to obtain a fine-scale saturation distribution. A visual display can be output responsive to the fine-scale saturation distribution.