8/11/2019 Guidelines for Well Model and Lift Table

1/2

NEL Standard Workflow for Well Vertical Flow

Performance (VFP) Tables

ObjectiveThe following document was written to guide petroleum engineers in how to build VFP tables to

be used in ECLIPSE to forecast production when using a reservoir simulator.

Concept

VFP Tables are, basically, a series of rate dependent BHP values, like the ones generated in

the outflow curves in Nodal Analysis, arranged in a format that can be read by a reservoir

simulator (e.g. ECLIPSE, IMEX, VIP, etc) with the objective of calculating the well BHP to quick

forecast well production under certain conditions (GOR, Wcut, Pwh, Qinj, etc.).

During the forecast simulation, the reservoir model gets into the VFP table using a specific value

of Ql, Wcut, GOR, Qinj, and Pwh and interpolates the corresponding BHP from the tables

curves. Once the BHP is determined, the reservoir simulation model calculates the wells liquid

and/or gas rate, depending on the assigned well PI and the process repeats every time step.

Thus, VFP tables are a series of outflow curves at different conditions of GOR, Wcut, Pwh, Qinj,

etc. that are used to predict the wells production under certain scenarios.

Input Data

The following are the required input

Input Data Recommended Source

Reservoir Fluid Data Reservoir Engineer

Wellbore Configuration and

Equipment Data

Completion/Production

Engineer

Well deviation data Geologist and Petrophysicist

Welltest data Production Engineer

Reservoir Fluid data

NEL standard tool for Well model construction have options for you.Black Oil Model

The black oil model configured such that the PVT module provides a look up table for the well

model solution process. The chances are that you will be using the black oil model 98% of the

time. You are required to do the following;

1. Calibrate the laboratory data (Psat, GOR, Density etc)

2. Select the best correlation that matches the laboratory data with minimum deviation on

the Psat

8/11/2019 Guidelines for Well Model and Lift Table

2/2

Compositional Model

The compositional model is set up to use the equation of state (the to calculate the fluid

properties. The well model solution process with solve EOS at every solution step to estimate

the fluid properties using the EOS and fluid composition. The key input parameter for this option

in the reservoir fluid composition. You will use this option 5% of the time. It is extremely valuable

to use this when modelling a well that is tied to gas sales agreement.

Wellbore and Deviation data

The wellbore and deviation data are mostly consistent

Welltest Data

The welltest data will ideally comprise of the following;

1. Flow rate (Q)

2. Basic Sediments and Water (BSW)

3. Gas Oil Ratio (GOR)

4. Choke Size

5. Flowing Tubing head pressure (THP)

6. Flowing bottom hole pressure (FBHP)

In the event you do not have one or both of the last two parameters (FTHP or FBHP), you can

use the Gilbert choke model or PI to estimate the missing parameter.

Selecting and Calibrating Valid Well test

Sensitivity Range

The table below presents the suggested sensitivity range;

THP (psig) BSW GOR (scf/stb) Liquid Rate (B/D)

60 0 100 100

10 Steps 10 Steps 10 Steps 20 Steps

1000* 100 5,000 5000**

* The THP can be increased to a maximum of 2,500 psi for gas wells

** The Liquid rate can be increased to a maximum of 7,500 b/d for horizontal model

ExportingThe recommended export format will be based on recipient of the model.

You can use ecl format for Eclipse and

You can use GAP format for GAP and MBAL