Simulation 1 Overview

8/11/2019 Simulation 1 Overview

1/15

Introduction to

Simulation

Prepared by:

Thomas W. Engler, Ph.D.,P.E.Fall 2009


2/15

Why develop a reservoir simulation

model?

provide detailed performance predictions

for multiphase, heterogeneous reservoirs

Evaluate single well performance

Improve/optimize reservoir management


3/15

Modeling Approaches

1. Analogy

2. Physicala. Elemental core

b. Scaled packed

sand, cut stone

c. Field pilot single

pattern


4/15

Modeling Approaches

3. Mathematical

Vol( u)in ( u)out

10

100

1000

0.1 1.0 10.0 100.0

time

Pressure

Material Balance Statistical

Decline Curves

-0.00025x -0.00035x

-0.0052x

1

10

100

1000

Aug-87 May-90 Jan-93 Oct-95 Jul-98 Apr-01

Time (months)

Rate(mscf/d)

Analytical

Numerical


5/15

Comparison

Simulation to Field Pilots

Lack of repeatability

(one shot proposition)

Time for evaluation of

pilot results can belengthy

Costly

Real conditions Results: may be used

to modify model

Can repeat frequently

from initial conditions

Time to evaluate

results is fast Lower cost?

Simulates field

conditions Results: May be used

to design pilot.


6/15

Comparison

Simulation to Lab models

Core experiments use

actual reservoir rock

and fluids.

Results distinguishmechanisms of fluid

flow

Measurement/human

error

Scale????

Imaginary reservoir,

requires physical

model results

Numerical dispersion Grid orientation

effects

Solution techniqueaccuracy

Scale????


7/15

Scale

oqo

wqw

pb

gh

o

w

pc

gh

Simulation scale

Reservoir scaleCore scale


8/15

Comparison

Numerical to Analytical

Zero-dimensional

tank models

No variations in

parameters withregard to space or

time

Multi-dimensional

Allows for variations

of parameters

Based onfundamental

equations


9/15

Planning

StepProblem Definition

Data Review

Data Acquisition

Model Design

History Matching

PredictionEditing, analysis, reporting

Time


10/15

Problem Definition

assemble information about the reservoir

and operations

define practical objectives and scope of

study

preliminary analysis of the reservoir

mechanics, e.g., coning, gravity


11/15

Data review and acquisition

review of quality and quantity of data,

sources of data

assess if sufficient data is available to meetobjectives, or revise objectives or obtain

more data

sensitivity of reservoir performance toparameters!


12/15

Model Design

Individual well or full-field model? Radial or

cartesian?

Type of reservoir fluid? Type of process to model?

Quality of geologic and petrophysical data?

Time and cost constraints?


13/15

History Matching

adjust input variables to validate model

through matching performance parameters

A successful history match does not

guarantee a field match

Uncertainty.nonuniqueness


14/15

Prediction

Predict future performance to make better

management decisions

Perform sensitivity analysis and observe

impact of results


15/15

Prediction-Example

Medford

Documents

Simulation 1 Overview