What Is GasPal and Why Use GasPal? · An auxiliary program history matches production data for an...
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Maraco Inc 2018
Transcript of What Is GasPal and Why Use GasPal? · An auxiliary program history matches production data for an...
Maraco Inc 2018
What Is GasPal?
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Hello GasPal GasPal is an integrated nodal analysis gas system
simulator incorporating multiple reservoirs and surface network.
We believe GasPal to be the world’s most efficient and speedy integrated nodal analysis system. But do not be alarmed thinking quality means complexity for the user. Ease-of-use is a guiding principle in all programming in GasPal. In the last year we spent many hours redoing the user interface to make it friendlier.
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GasPal Is Mature This program is not something new. Version 1 of our
system was first put to use by gas producing companies in 1996, 22 years ago. Some of those initial users are still on line. Version 2, a much more sophisticated and comprehensive system -- which we named GasPal – passed its beta test in 2003 and has been on line since. Many enhancements have been added over the years -- and such efforts are continuing as we speak.
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GasPal Is Powerful Consider this truth. GasPal’s most complex application
includes over 800 gas wells producing from formations with as many as 30 active layers perforated over a span of time. The surface network consists of several hundred pipe segments subdivided into sections carrying gas at different operating pressure levels through compressors to several offtake points. A 30-year projection with this application using monthly time steps requires about 30 minutes with a modern PC.
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GasPal Is Easy To Use Sounds complex?? That model certainly is. However,
let’s say you have a property producing from 4 reservoirs each with 2-4 layers producing through a surface network with say 20 pipe segments to a single delivery point. Give us the data and we can have an actual operating model ready for history matching in ONE hour.
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Tailoring GasPal’s Well Model An auxiliary program history matches production data
for an individual well using a range of correlations for entrained liquid. Once you select the best correlation for a well the parameters for that well are -- with the press of a button -- imported into GasPal’s base data file ready for use.
If a flow table generated by Prosper or other software is input, GasPal curve-fits the data for use in calculations. Likewise for each segment of pipe in the surface network.
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GasPal’s Streamlined Input & Output GasPal’s input and output contains a large array of
graphical and tabular features simplifying data input and providing totally comprehensive results in the most convenient and usable form. A recently added feature models a plant outputting dry gas, condensate and natural gas liquids (NGL).
An interesting fact. GasPal, Version 1 & 2, has been a joint development of two engineers, both of whom are Professors of Petroleum Engineering.
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What Is GasPal? GasPal is an integrated gas reservoir simulator that
Integrates formation, tubing and surface lines
Models multiple phase flow in formation and pipes
Combines cluster of reservoirs with multiple layers
Allows multiple offtake points
Allows loops and splits in surface network
Models production and injection wells for storage reservoirs
Has different production modes such as Free Flow, DCQ and Nomination
Makes short, mid and long term planning with hourly, daily and monthly time step
Imposes quality constraints such as CO2 content
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Integrated Nodal Analysis
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Layer 1
Layer 2
Layer 3
Reservoir Tubing
Aquifer
Surface
Surface Line
Gas
Gas
Gas
Modeling Each Reservoir With Arbitrary Grids
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Arbitrary grids allow fewer cells to model a reservoir effectively. Fewer cells translate to fast simulation. GasPal models well interference effectively with a grid tailored to the reservoir by the user.
Modeling Gas, Water and Oil Flows in Reservoir
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Modeling Multiple Phase Flow in Tubing
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Industry standard correlations are used to model tubing pressure drop for multiple phase flow. Users can further calibrate each correlation against well test data, using a least squares method imbedded in an effective proprietary algorithm.
Modeling Fluid Flow in a Surface Network
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1. Loops and splits in surface lines
2. Multiple offtake points
3. Compressors and other surface facilities such as separators
A Prosper table can be used here
Model Production System With Multiple Platforms and Complex Surface Network
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Modeling Gas Storage Reservoirs
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Withdrawn
Injection
Shut-in
Why GasPal?
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GasPal Is Versatile GasPal can model a production system as simple as a single
simulation cell, single layer, or as complex as 50+ platforms with 800+ wells and 5000+ layers.
GasPal can make short, medium and long term forecasts with hourly, daily, weekly or monthly time steps.
GasPal has multiple production modes to model different scenarios:
Free flow without choke and other mechanical restrictions
Limited flow considering sand-control, pipe vibration, market demand, spare capacity, CO2 constraints and more.
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GasPal Is Fast A typical 30-years simulation run takes
Seconds for a single platform
Minutes for a moderate complex system
Less than 2 hours for a 800+ wells, 5000+layer system
Fast simulation allows users to make different case-studies to answer “what-if” questions quickly
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GasPal Is User-Friendly: Input GasPal runs on any Windows-based computers
without special requirements.
GasPal has carefully crafted Graphic User Interface, designed by petroleum engineers, used and improved by petroleum engineers
Users can enter data
Using conventional methods such as typing data reservoir by reservoir, or
Using copy-and-paste from Excel through several “Grand Data Input” panels
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GasPal Is User-Friendly: Output GasPal has extensive built in output graphs (150+ types
and growing) so users can analyze the simulation results without leaving GasPal.
GasPal also writes output results into MDB database files so users can use existing tools to do other analyses
GasPal can also export output into text/CSV files that can be readily loaded into Excel.
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Sample Output and Menu for Output
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GasPal Has Many Features Convenient history match
Well gas, water and condensate rates
Flowing, wellhead and gauge pressure
Manifold pressure, rate and CO2 content
Numerous well inflow options Standard Darcy’s law (drainage radius, k, h & skin)
AB method
C/n method, etc.
Numerous ways to model water and condensate production Darcy’s law and relative permeability curves
Empirical WGR/CGR curves for wells or layers
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Continuously Improving GasPal is updated regularly to add new features. Some
of the recent additions are
Well and surface facility downtime
Platform maintenance scheduling
Gray well cutoff rate method
Non-adiabatic compression modeling
Liquid removal at various surface locations
Time-dependent surface network
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Fast Services From Maraco Quick response to answer users questions
Proactive to new features requested by users
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Dr. Elmer Dougherty
President, founder Maraco.
Professor Emeritus, Petr & Chem Eng, USC - University of Southern California
SPE – Distinguished Member & Legion of Honor
50 years of reservoir simulation and optimization experience.
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Dr. Jincai Chang
Petroleum consultant and software engineer.
23 years of experience in reservoir simulation and optimization
Teaching “Reservoir Simulation” at University of Southern California, Los Angeles, California, USA
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