Parametric SCAL modeling

Frode Lomeland

Leading Advisor Reservoir Flow Parameters

Statoil

Stavanger 14 November 2013

Classification: Internal 2013-08-21

Outline

• Introduction

• Workflow

• Trend functions and analysis

• Local trend curves and saturation regions (bins)

• Extension of SCAL model to include Hamon’s theory

• Quality control and deliveries

• Short summary of benefits of parametric SCAL modeling

2

SCAL contributions to IOR / EOR 1 • Special core analysis (SCAL) is a study of multi-phase fluid flow in rock

• Traditionally SCAL studies

− involves laboratory experiments, and

− deliver a model for reservoir flow parameters (RFP or SCAL model) that is

− used in the reservoir simulator

• Most IOR / EOR methods try to

− produce remaining oil left behind injection front by the original drainage plan

− produce oil that is not swept by the original drainage plan

• A high quality SCAL model is therefore recommended

3

SCAL contributions to IOR / EOR 2

• A high quality SCAL model means

− more correct reference when evaluating other injection fluids as EOR

− more correct reservoir flow parameter model which means

• more correct reservoir simulation model which means

− better prediction of remaining oil production for existing drainage plan

− better understanding and prediction of remaining targets for in-fill

drilling

• One way of preparing high quality SCAL models is to use

− parametric SCAL modeling

4

Short on parametric SCAL modeling

:

• Parameterize SCAL properties, relative permeability and capillary pressure,

based on formulas that can be used for all scales - from the small pore

scale or core plug scale and up to the large scale of grid cells in full field

models.

:

• Relative permeability and capillary pressure are represented parametrically

by the LET family of formulas (LET is a reference to the three authors in the

first paper on these formulas). Interpreted laboratory results are stored in a

parametric SCAL database.

• Trend analysis of SCAL parameters are significantly improved, and

consistent SCAL models with uncertainty are generated.

• Both up-scaling of SCAL data and history matching of multiphase flow are

improved and facilitated by using the parametric LET representation (not

discussed in this presentation).

SCA 2005-32 Lomeland, Ebeltoft and Thomas

Work flow for SCAL modeling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

Work flow for SCAL modeling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

Work flow for SCAL modeling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

Work flow for SCAL modelling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

Work flow for SCAL modeling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

PAI selection Filter to field / litho-stratigraphic formation or group

Kabs vs Swir Porosity vs Swir

PAI - Porosity, Absolute permeability, Irreducible water saturation

• Increasing Swir in saturation end-point scaling gives an increased curvature of Krow

− This is opposite of what flow parameters from SCAL experiments show

• Increasing Swir in trend analysis shows a smaller L-parameter for Krow

− I.e. a more water wet system with less curvature

Trend analysis promotes more saturation regions

Curve shape parameters, end-point

saturations and end-point relative

permeability values are flow parameters Flow parameters vs. Swir

Residual saturation vs. Swir

• Increasing Swir in saturation end-point scaling gives an increased curvature of Krow

− This is opposite of what flow parameters from SCAL experiments show

• Increasing Swir in trend analysis shows a smaller L-parameter for Krow

− I.e. a more water wet system with less curvature

Trend analysis promotes more saturation regions

Curve shape parameters, end-point

saturations and end-point relative

permeability values are flow parameters

• Increasing Swir in saturation end-point scaling gives an increased curvature of Krow

− This is opposite of what flow parameters from SCAL experiments show

• Increasing Swir in trend analysis shows a smaller L-parameter for Krow

− I.e. a more water wet system with less curvature

Trend analysis promotes more saturation regions

Curve shape parameters, end-point

saturations and end-point relative

permeability values are flow parameters Flow parameters vs. Swir

Residual saturation vs. Swir

Basic definitions – WOGn

WOGn - notation:

• Bookkeeping system for the flooding processes. It consists of a triplet –

W-O-G - and a cycle number - n.

• The positions in the triplet are fixed and reserved for

• Water,

• Oil

• Gas

• Each position state the phase-saturation change - D, I or C meaning

• Decreasing,

• Increasing or

• Constant

The nomenclature is prepared for higher cycles to

complete multi-cycle hysteresis boundary curves

Local trend curves: IDC2 Krwr SS+USS

Classification: Internal 2012-05-10 16

CFG+PP

Flooding

Calibration point moved to an

abnormal position for

visualization purposes

Local trend curves: IDC2 Sendra hist. match

Classification: Internal 2012-05-10 17

Saturation regions and flow parameter values ATZ

Classification: Internal 2012-05-10 18

ATZ – Above (capillary)

Transition Zone

Initialization of Sw and Flow Parameters

19

• Chart from Ghedan 2012

• Corey exponents vs depth

• ATZ =

Above Transition Zone

• CTZ =

Capillary Transition Zone

Chart from Ghedan 2012

ATZ

CTZ

Hamon SPE-63144-MS

Saturation regions and RFP values in CTZ

20 Hamon SPE-63144-MS

Kr are distributed vs Swinit via SATNUM Wettability changes vs height above WOC and permeability

21

In capillary transition zone Above capillary transition zone

Hamon SPE-63144-MS

QC using global trend functions

Classification: Internal 2012-05-10 22

Relative permeability with uncertainty

Classification: Internal 2012-05-10 23

Benefits of parametric SCAL modeling

:

• Special core analysis (SCAL) is a cornerstone in modeling multiphase flow of

injection strategies for both basic and improved oil recovery processes.

Improved SCAL models imply more reliable reservoir simulation results.

• Proper SCAL models may improve the simulation of reservoir performance

and the quantification of SCAL related uncertainties, possibly worth billions

of dollars.

• The distinct advantages of using a parametric description of SCAL

properties, far outweigh the disadvantages of minor loss of quality of the

selected formulas (or correlations) when doing trend analysis in a large

database.

:

• Implemented as an evaluation tool in Statoil’s portfolio

• Statoil is probably industry leader within parametric SCAL evaluation and

modeling

Basic elements of parametric SCAL modeling

Classification: Internal 2010-11-01

26

Presentation title

Presenters name

Presenters title

E-mail address ……@statoil.com

Tel: +4700000000 www.statoil.com

Classification: Internal 2013-08-21

Work flow for SCAL modeling

Caesar parameters & scalars

Cleopatra (Kr, Sr) Kr curves, scalars, exp data

Sendra (Kr, Sr, Pc) Numeric interpretation of exp

Hadrian scalar & curve generator

Eclipse & Stars

Servilia (Pc) Pc curves, scalars, exp data

Laboratory data Eclipse e-Core

Key Publications • Lomeland F., Ebeltoft E. and Thomas W.H.: “A New Versatile Relative

Permeability Correlation”. Paper SCA 2005-32, International Symposium of

the Society of Core Analysts held in Toronto, Canada, 21-25 August, 2005.

• Lomeland F. and Ebeltoft E.:“A New Versatile Capillary Pressure

Correlation”. Paper SCA 2008-08, International Symposium of the Society

of Core Analysts, Abu Dhabi, UAE, 29 October – 2 November, 2008.

• Lomeland F., Hasanov B., Ebeltoft E. and Berge M. 2012. A Versatile

Representation of Up-scaled Relative Permeability for Field Applications.

Paper SPE 154487-MS presented at the EAGE Annual Conference &

Exhibition incorporating SPE Europec held in Copenhagen, Denmark, 4-7

June 2012.

• Lomeland F. and Ebeltoft E.:“Versatile Three-phase Correlations for

Relative Permeability and Capillary Pressure”. Paper SCA 2013-034,

International Symposium of the Society of Core Analysts, Napa Valley,

California, USA, 16–19 September, 2013.

Classification: Internal 2010-11-01