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Article # 0055



R.L. Langley, P.E.




          The outline described herein is a proven basis for developing a detailed training program for new hire midstream (natural gas processing) engineers in preparing them for their first field engineering assignment. The objective here isn’t to make new engineers “process engineers”, but to give them a solid foundation and information resources to support them in their first field experience. Naturally, if time and circumstances allow, these sessions could be augmented by actual field trips to see firsthand the practical application of the material covered in each section.


            The timeframes and subjects noted are guidelines only, and will have to be adapted to the organizational structure and desired result. It’s anticipated that each section should be mentored by experienced, subject matter experts in that area.


Introduction to Gas Processing (12 hours)


          This program segment is designed to give the new engineer a basis for the history, technology, and terminology of the gas processing industry. The following are the components and brief explanation:

·        Components of natural gas

·        Industry specifications for various products

·        Utilize simple block flow diagrams to show gas flow from a wellhead separator, through field pipelines and compressor stations, gas processing plant, and final product distribution.

-Field Units (separators, production, measurement)

-Gas gathering systems (pipelines, measurement, and compression)

-Plant inlet separation-two or three phase

-Condensate knockout and handling

-Gas treating (types, methods and applicability)

-Sulfur production plants (types, methods, yields)

-Gas dehydration (methods and applicability)

-NGL Plants (types/technology, yields, methods of operation)

-Product fractionation-different types of products and end uses


Reading/Reference Materials:

-The Gas Processing Industry-Origins & Evolution by Ron Cannon (published by Gas Processors Association-Tulsa, Okla.)  This book is an excellent resource regarding the origin and the evolution of technology in the gas processing business.



            -Following Published by University of Texas Petroleum Extension Service (PETEX):

                        -Field Handling of Natural Gas

                        -Plant Processing of Natural Gas                                  


Introduction to Gas Processing Calculations (8 hours)


            This segment covers the following basic calculations used in gas processing:


·        Ideal gas law

·        Equation of State

·        Compressibility factor

·        Gas Density

·        Standard vs. Actual conditions

·        Liquids density and specific gravity

·        Gas specific gravity (calculating gravity of a gas mixture)

·        Concept of gallons of product/mcf, or “GPM”, where “mcf”=1,000 cubic feet of gas

·        Higher (gross) and lower (net) heating values of gas

·        Product recoveries through a NGL Plant

·        Company owned/subscribed software for gas processing simulations, unit operations, and targeted system calculations, etc.



Reading/Reference Materials (below will be used throughout training):

            -Plant Processing of Natural Gas (Chapter 1)

            -Data Book on Hydrocarbons-J.B. Maxwell

-Gas Processor Supplier’s Association (GPSA) Data Books (Volume I, II)

-Gas Conditioning and Processing (John M. Campbell and Co. series)

-Handbook of Natural Gas Engineering (Katz et al, McGraw Hill)

-Perry’s Chemical Engineer’s Handbook

-Gas Engineer’s Handbook (The Industrial Press)

-Handbook of Chemistry & Physics (CRC Press)

-Dictionary of Chemical Terms (McGraw Hill)


Mollier Diagrams (6 hours)


          This segment is to familiarize the new engineer with Mollier Diagrams and how they are used for vapor and liquid equilibrium calculations vs. temperature, pressure for various natural gas hydrocarbon components.  The following is covered:

·        What a Mollier diagram is and what it represents

·        Mollier diagram of pure and multicomponent compounds

·        Iso (temperature and pressure) flash and uses

·        Adiabatic flash and uses (Joule Thompson expansion, heat exchange)

·        Isentropic path and its uses (compressor and expander calculations)

Reading/Reference Materials:

            -Maxwell’s Data Book on Hydrocarbons

            -GPSA Engineering Data Books


Gas Treating (12 hours)


          This segment is to familiarize the individual with the various gas treating processes, their applicability, and economics. Amine systems will get emphasis, and procedures for basic treater calculations can be presented. The following is covered:


·        Define the “Acid Gas” components in natural gas

·        Explain why acid gas components must be removed-specifications for liquid products, and residue gas

·        Physical and chemical treating processes

·        Describe various amine based processes & reactions with hydrogen sulfide and carbon dioxide components

·        Amine treater process flow  & purposes of each piece of equipment

·        Solution loadings and calculations

·        Circulation rates of amine for various parameters

·        Which amine type to use-contract requirements, pressure, temperature constraints, and overall costs.

·        Calculations for

-Reboiler heat duty and surface area

-Lean/Rich heat exchanger heat duty and surface area

-Amine overhead cooler duty, area and fan horsepower

-Amine charge pump horsepower

-Amine contactor diameter, trays and height

-Utility equipment-fuel, electricity, water           

·        Controls for amine treating units

·        Monitoring treating units for loading, corrosion rates and utility consumptions


Reading/Reference Materials:

            Dow Chemical  Gas Conditioning Fact Book

            Laurence Reid Gas Conditioning Conference-Fundamentals Manual

            Plant Processing of Natural Gas (Treating Section)

            Gas Treating and Sulfur Recovery (John M. Campbell & Co. series)


Sulfur Plants (8 hours)

            The purpose of this section is to familiarize the trainee with the basics of various sulfur recovery technologies.  Basic information includes the following:

·        Why sulfur has to be removed

·        Various methods-Claus, SCOT  & CBA. (Applicability  of each)

·        Claus (most common) flow diagram, operating parameters and controls

·        Monitoring reactor beds/bed decay and determining changeout time

·        Safety considerations in sulfur plant design and operation

Reading/Reference Materials:

            Plant Processing of Natural Gas (Sulfur Plants)

            Sulfur Recovery- Paskall & James

            Gas Treating and Sulfur Recovery (John M. Campbell & Co. series)


Hydrates and Hydrate Inhibition (4 hours)


            This training segment introduces hydrates—what they are, causes, problems they create and how to inhibit them. This is important to both field pipeline systems as well as processing plants. Other aspects of this section include:


·        The effect of composition (especially hydrogen sulfide) on hydrate formation

·        Removal/abatement of hydrates and safety precautions

·        Hydrate Inhibition-Water content of  the gas, Inhibitors and injection rates, methods


Reading/Reference Materials

            Field Handling of Natural Gas (Hydrates Section)

            GPSA Data Book (Hydrates section)


Dehydration of Natural Gas (8 hours)

This segment covers the following:

                         -Why remove water from natural gas?

                        -Methods used to dehydrate gas (solutions like glycol, or solid desiccant)

                        -Applicability of various methods

                        -Process flows for dehydration units

                        -Monitoring performance of the unit

Reading/Reference Materials:

            Field Handling of Natural Gas (Dehydration)

            Plant Processing of Natural Gas

            GPSA Engineerng Data Books


NGL Extraction Plants (16 hours)

             This segment covers the various methods of extracting natural gas liquids from a natural gas vapor stream after treating and dehydration.  The various methods are as follows:


            -Absorption oil extraction

            -Refrigerated absorption oil

            -Straight Refrigeration

            -Joule-Thompson (JT) valve expansion cryogenic process

            -Turbo Expander cryogenic process


            Aspects covered are economics, utility requirements, recovery/yields of NGL components, and testing plant products to meet specifications.


Reading/Reference Materials:

            -Plant Processing of Natural Gas

            -GPSA Engineering Data Books

-Plant Operations Test Manual (Gas Processors Association-Tulsa, Okla.)


Fractionation Systems/Tower Internals (12 hours)


            “Fractionation” is the process by which the mixed LPG stream is separated into various components or “fractions” (for further processing or sales) by heating and cooling under pressure inside a closed vertical vessel called a “tower” with internal trays, packing, etc. This segment is to familiarize the individual with the fundamentals of simple fractionation methods and internal configurations of towers. Computer simulations and programs may be utilized for this section.


·        What is fractionation, and why is it done?

·        How is it done?

·        Basic parameters

-Performing a mass/mole and heat balance on a tower

-Keys (volatilities, reflux ratios, heating/cooling methods)

-Product purities vs. number of stages (trays)

·        Sizing towers (diameter, height)

·        Components & design of-piping, reboilers, cooling, reflux vessel, pumps

·        Control of fractionation towers and required inputs

·        Various energy saving methods of design-thermocoupling, heat pumps


 Reading/Reference Materials:

            -GPSA Engineering Data Books

            -Plant Processing of Natural Gas (Fractionation)

            -Distillation Design (Henry Z. Kister-McGraw Hill publisher)

            -Distillation Operation (Henry Z. Kister-McGraw Hill publisher)


 Utility Systems (4 hours)

            This segment is to familiarize the engineer with the required facility support utilities systems.  The design, safe operation, control and maintenance of the following systems should be reviewed:


·        Propane Refrigeration systems

·        Steam Heat systems, including boilers/waste heat boilers

·        Heating Oil systems

·        Cooling Water-Cooling Towers

·        Air Compressors (instrument, utility)

·        Inert gas systems (if  used for purging, evacuation, etc)

·        Water systems-utility, boiler feed water (treatment of for corrosion, scaling)


Reading/Reference Materials:

            -GPSA Engineering Data Books

            -Ingersoll Rand Compressed Air and Data Book

-Betz Handbook of Industrial Water Conditioning

            -The NALCO Water Handbook


 Instrumentation and Controls (6 hours)

          This segment covers the basics of process control including reading process and instrumentation diagrams (P&IDs), identifying key parameters needing monitored/sampled, various  hardware components and how they work, feedback systems and method transmitted (pneumatic, electrical), instrumentation/devices, use of programmable logic controllers, control logic software and how it all works together to affect a holistic controlled system.



            Fisher Control Valves Handbook

            Field Handling of Natural Gas

            GPSA Engineering Data Books


Compression (12 hours)

          This segment could be a lengthy training program unto itself as there are many aspects to the science and applicability of gas compression. This segment covers the different types of compressors and drivers—design, sizing and applicability of reciprocating, centrifugal, vane and screw type units.  (Trainee needs to have covered Mollier diagrams before this section.)


            General topics include:

·        What  compressors do/how

·        Various types of compressors/drivers and applicability

·        Integral vs. Separated machines

·        Volumetric efficiency

·        Rod Loading (reciprocating units)

·        Number of compression stages

·        Interstage equipment-scrubbers, coolers, etc.

·        Controls & Instrumentation

·        Horsepower calculations

·        Driver requirements (fuel gas, diesel, electrical, other)

·        Emission Standards & Permits required

·        Maintenance considerations


Reciprocating Compressors:

·        High vs. Low Speed & applicability

·        Integral vs. driven

·        Efficiency-turbochargers, ignition systems

·        Capacity-cylinder sizing and selection

·        Clearance pockets-what they are, design & use of

·        Pulsation Dampeners

·        Vibration/Piping considerations


Centrifugal Compressors:

·        How centrifugals work

·        Applicability

·        Performance Curves-how to read

·        Surge Control/Recycling

·        Vibration Monitoring

·        Turbine driven

-Exhaust Waste Heat Recovery Systems (Applicability & Economics)

                        -Ambient conditions affect on HP-elevation, ambient temp, humidity


Reading/Reference Materials:

            Field Handling of Natural Gas (Compressors Section)

Major manufacturers’ catalogs & data books (Dresser-Rand, Waukesha, Cooper Energy Services, Worthington, Solar, Ingersoll Rand “Compressed Air & Data Book.

GPSA Engineering Data Book (Compressors)


Pipelines and Plant Piping (8 hours)

            This segment is to familiarize the engineer with various calculations, tools and references, pipeline safety, and right-of-way considerations. The following will be covered:


·        Bernoulli’s Theorem and application

·        Hazen-Williams equation and usage

·        Calculations

-Single phase flow (gathering systems, liquid, steam flow)

-Two phase flow (pressure drop calcs, slugging, pigging, “drips”)

-Example Problems to solve:

*Knowing distance, pressure, & composition of gas discovery, size line to get into gathering system to plant with proper velocity.


*Knowing the operating parameters of your system, there’s a plant processing a known amount of gas being shut down some distance away with an existing known sized line and operating parameters on that end. Calculate how much of the gas can come through the line to your system.


*In a known composition, sized, pressures and length of a liquids pipeline system, calculate how much liquid can be delivered at the chosen termination point.


*Calculation of delivery pressure, velocities in two phase flow system given beginning point pressure, composition of phases and line size.


·        Tools

-Simple pipe segments-hand calculator

-Repetitive calculations-laptop/programs

-Network & two phase-off the shelf software (Pipephase, etc)

·        Materials used in pipeline systems




·        Pipeline Safety

-DOT Regulatory Overview-49 CFR Parts 186-199 “Transportation”

-Class Locations

-Valve Spacing\

-Pipe Strength & Thickness Calculations


·        Right-of Way/Maps/GPS Systems

-Selection of routes

-Costs of ROW

-Dealing with Landowners

-Maps (Topographical, Gathering/Residue systems, Alignment Sheets)

·        Pipeline Construction

                                    -Terrain challenges

                                    -Road/Railroad crossings

                                    -Crossing bodies of water

                                    -Pipe Bending

                                    -Materials Testing Records (MTR) and need of

                                    -Hydrostatic Tests

-Pipe joining methods (flanged, screwed, welding, poly fusion, Zap Lock)

                                    -Pipe coating & wrapping



            -Crane Flow of Fluids Through Valves, Fittings & Pipe (Tech Paper 410)

            -GPSA Engineering Data Books

            -Any in house software used for pipeline simulations     

            -Plant Processing of Natural Gas (PETEX)

            -Pipeline Rules of Thumb Handbook (McGraw-Hill)

            -Tube Turns Pipe Fittings


Other Process Equipment (8 hours)


·        Pumps

-Types & application (positive displacement, rotary, centrifugal, gear, etc)

-Design/Specification considerations for given conditions

                                    -Pump Curves (how to read, apply & use in performance troubleshooting)

                                    -Restaging or modifying pumps for different conditions

                                    -Pressure drop calculations through systems

                                    -Safety designs for hazardous services (tandem seals, water deluge)

                                    -Sizing/Specifying pumps for quotation


·        Heat Exchangers

                                    -Design considerations

                                    -Types & application (shell & tube, aerial, plate fin, atmospheric, etc.)

                                    -Calculating required exchange surface knowing inlet/outlet conditions

                                    -Sizing/Specifying heat exchangers for quotation


·        Separators, coalescers & filters

-Different types, purpose/uses & applicability for gas, 2 phase, liquids

-Sizing/Specifying for quotation


·        Valves (gate, globe,ball,control,check,relief, etc) & Pressure regulators

-Different types, configurations, purpose/uses & applicability

-Various actuators and application of

-Sizing & specifying for given conditions, including seats/metallurgy




-GPSA Engineering Data Books

            -Field Handling of Natural Gas

            -Fisher Regulator Handbook

            -Kingtool Catalogue (separators, filters, coalescers)

            -Peco Catalogue (separators, filters, coalescers)

Cost Estimating, Economics, and Expenditure Preparation (5 hours)

          This section covers the cost estimating procedures, tax obligations, economics/payout calculations, and Authorization For Expenditure (AFE)/Appropriation Request (AR) preparations. Interface with Project Engineering on “hurdle rate”/profitability required for a project to move from conceptual to AR stage. Work with Financial Dept. on terminology and parameters used, as well as risk analysis of projects. Included are following:


·        Economics basics-what it is and why do it?

·        Cash Concepts

·        Discounting

·        Cash Flow Evaluations


-Net Present Value (NPV)

-Discounted Cash Flow Rate of Return (DCFROR)

-Discounted Profitability Index (DPI)

-Profitability Index

·        Risk/Return guidance (corporate policy)

·        Tax considerations

·        Lease/Purchase Analysis

·        Any software/programs used on above


Two typical sample problems included in this section for the engineer to work through could be (1) Currently leasing a compressor and want to do an economics analysis to purchase vs. continuing lease payments, and (2) Grassroots or plant modification project designed to save money or generate income from a defined capital outlay.


Safety in Designs Considerations (8 hours)

          Last covered in this paper, but certainly not least in importance is the safety and environmental aspects of engineering work.  The engineer should always consult and refer to Corporate Engineering/Construction Specifications and Policies regarding safety in designs. However, for the midstream industry, there are several codes and standards that are worthwhile references and reading for the novice engineer:


          API 2510 – Design and Construction of Liquefied Petroleum Gas Installations (LPG)

API 2510A – Fire Protection Considerations for the Design and Operation of LPG Storage Facilities

API 2218 – Fireproofing Practices in Petroleum and Petrochemical Processing Plants

API RP 540 – Electrical Installation in Petroleum Processing Plants


NFPA 15 – Standard for Water Spray Fixed Systems for Fire Protection – 2007 Edition

NFPA 30 – Flammable and Combustible Liquids Code

NFPA 58 – Liquefied Petroleum Gas Code

NFPA 59 – Utility LP – Gas Plant Code

NFPA 59A – Standard for the Production, Storage and Handling of Liquefied Natural Gas 

NFPA 70 – National Electric Code

NFPA 214 – Standard on Water Cooling Towers

NFPA 850 – Recommended Practice for Fire Protection for Electric Generating Plants and High Voltage Direct Current Converter Stations


The first three are primary (API 2218 is referred in API 2510) references as they’re LPG operations specific.


            The main objective here is to include all of the safety/environmental aspects and specifications in the costs for the original design and job scope of the project. What one needs to avoid is “completing” a project, only to have the Loss Prevention, Safety & Environmental Departments and/or the company’s insurers make a survey of findings after the fact turns out to be an expensive laundry list of what should’ve been included in the initial AR.


Other Training

            It’s beyond the scope of this writing, but to provide a well rounded basis for the engineer before the first field assignment, the following additional training aspects should be considered:


·        Construction Contracts & Administration

·       Measurement & Quality Control (products, plant gas balances, etc)

·        Mechanical Integrity and Root Cause Failure Analysis

·        Environmental, Safety & Health (Corporate Policy, regulations that affect industry, how company maintains compliance, etc.)

·        Project Management

·        Gas Supplies & Contracts

·        Business Development

·        Land/Right-of-Way\

·        Government Regulations & Services (includes FERC)

·        Marketing of Products

·        Accounting

·        Supply and Distribution

·        Human Resources

·        Training

·        Internal Auditing

·        Legal Considerations in Conducting Business

·        Purchasing/Supply Chain Management



            This paper is but a brief outline upon which an organization could begin building a successful new engineer midstream training program.  It should be considered in this era because there are so few schools offering four year degrees in the field of midstream/gas processing (mostly technical new hires in the midstream business are from other engineering disciplines), and with the current trend to flat organizational structures, it’s imperative to “get up to speed” as quickly as possible. Hopefully, this writing provides some basis to begin that task in a structured manner.

R.L. Langley, P.E. #37315




New Engineers Training Program (no copyright)-Chevron Corp. /Warren Petroleum Company



Robert (Bob) Langley, P.E. holds a B.S. Degree in Chemical Engineering from the University of Oklahoma. For over 30 years he worked for Fortune 500 midstream (natural gas processing) companies as Process Engineer, Plant Engineer, Plant Supervisor, Plant Manager, Supply and Distribution Manager, Supply Chain Manager and Environmental, Safety & Health Manager. As both a facility and ES&H Manager, he had direct responsibility for administering implementation of certain aspects of the training described herein.


Article # 0055      TEST QUESTIONS:

1.  This paper was written to provide a outline for training new graduate engineers in

  1. The Refining Industry

  2. The Petrochemical Industry

  3. The Midstream (gas processing) Industry

  4. The Nuclear Power Industry

2.   This paper was designed to turn newly graduated engineers into process engineers almost instantly.   

  1. True

  2. False

3.   Most used Technical /Operations reference(s) included for training are

  1. The Gas Processors Supplier’s (GPSA) Engineering Data Books (Vol I,II)

  2. Field Handling of Natural Gas (published by PETEX)

  3. Plant Processing of Natural Gas (PETEX)

  4. All of the above

4.   Safety in designs is the lowest priority in the overall new engineer’s training program.

  1. True

  2. False

5.   One of the best references that covers the history and development of the midstream/gas processing industry is found in

  1. Wikipedia

  2. The Gas Processing Industry-Origins & Evolution (by Ron Cannon-GPA)

  3. Perry’s Chemical Engineer’s Handbook

  4. API 2510

6.   Facility utility systems should include training in the following:

  1. Process heating & cooling systems

  2. Air systems

  3. Water systems

  4. All of the above

7.  “Fractionation” is a training module whereby the engineer is familiarized with

  1. How the mixed LPG stream is separated for sales or further processing

  2. How atoms are changed to molecules thru centrifuges

  3. How separated gas streams are mixed together

  4. All of the above

8.   Mollier diagrams show vapor/liquid equilibrium and other information for various hydrocarbons at various pressures and temperatures. 

  1. True

  2. False

9.   The American Petroleum Institute  Code for Design and Construction of Liquefied Petroleum Gas Installations (LPG) is

  1. API 2510

  2. API 2600

  3. API 2288

  4. API 1404

10.   Bernoulli’s Theorem and the Williams-Hazen formula relate to

  1. Flow of  materials through pipes

  2. Sizing  high voltage electrical lines

  3.       Finding the depth of fresh water aquifers
  4. All of the above

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