The Physics And Chemistry Of Natural Gas Sampling And Conditioning
Author(s): Darin L. George, Ph.D., James N. Witte
Abstract/Introduction:
Industry research has led to changes in industry standards for natural gas sampling, such as the American Petroleum Institute (API) Manual of Petroleum Measurement Standards (MPMS), Chapter 14.1 and Gas Processors Association (GPA) Standard 2166. To best apply these standards, users should understand the physical phenomena that can lead to inaccurate samples. This paper will review the physics of natural gas sampling, including phenomena such as adsorption and desorption, vapor-liquid equilibrium, Joule-Thomson cooling, the use of the phase diagram as a sampling tool, and results of research on the physics of natural gas sampling that have led to developments in industry standards.
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Document ID:
36859151
New Techniques In LNG Sampling
Author(s): Ken Thompson
Abstract/Introduction:
Transportation of LNG (Liquefied Natural Gas) has increased with many new export and import terminals that have been built to date and more under construction or in the planning stages due to the increase in world demand of LNG. This demand has increased due to LNG being considered by many countries as the fuel of choice based on its safe properties, availability, cost, cleanness and ease of transportation. With the increase of liquefaction, storage, blending and transportation so has the need increased for Analytically Accurate measurement of the LNG in the realm of custody transfer. This has also led to new techniques in LNG sampling to help verify the measurement results. This paper will cover these new techniques in their approach and their unique challenges for the industry.
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Document ID:
2B3A09F6
Improving The Speed And Accuracy Of Water Vapor And Hydrogen Sulfide Measurements By Optimizing The Sample Transport System
Author(s): Phil Harris, John Kozich
Abstract/Introduction:
Natural gas is processed in order to meet customer specifications, such that it may be sold based on energy content. Suppliers and producers whose product does meet the customer / pipeline specifications are shut-in until it can be demonstrated that the product is within specification. With the advent of shale gas production and more complex and diversified streams entering the transportation, there is increased interest and demand for accurate, reliable and timely analysis of gas quality. The validity of such measurements can be strongly impacting by the sample gas transport system, the process by which the gas is removed from the process and move to the analytical systems. For trace components like moisture and hydrogen sulfide, the adsorption and desorption of the analyte from surfaces in the system must be considered. A thorough description of the effects as well as recommendations on system optimization is presented.
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Document ID:
D6015D93
Ngl Sampling
Author(s): Eric Estrada
Abstract/Introduction:
NGLs are hydrocarbons liquefied by gas processing plants containing ethane, propane, butane, and natural gasoline. Because of the varying size of molecules in an NGL stream, NGLs are susceptible to solution mixing effects. Solution mixing occurs when compounds containing different sized molecules are mixed together resulting in the smaller molecules fitting into the voids created by the structure of the larger molecules. A simple example of this effect can be described using sand and gravel. Assume a person is building a 4 thick patio base consisting of 2 of sand and 2 of gravel. In calculating the volume of each constituent required to produce a 4 high base, one would assume that they would simply be require equal amounts of sand and gravel. When the base is built up, there is astonishment when the resulting base is much less that 4 high with a large majority of the sand settled within the gravel. Similarly, when hydrocarbons of varying sizes are mixed together, volumetrically there will always be some solution mixing effect resulting from smaller molecules mixing in between larger molecules. Figure 1 shows molecular models of Normal Butane, Propane, and Ethane respectively and the variability in the size of the molecules.
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Document ID:
CD10A8D6
Injection Of Chemicals And Their Impact On Sampling
Author(s): Jay St Amant Brad Massey
Abstract/Introduction:
Historically natural gas producers have had the necessity to chemically treat gas streams for suitability of their intended purpose. One of the most common is methanol injection while others include corrosion and sulfur inhibitors. Each chemical has its own properties and manner in which it interacts with the natural gas stream and has to be dealt with accordingly. Methods and chemical types are ever changing as the evolution of natural gas production and gathering brings new challenges
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Document ID:
BB312A7C
Economics Of Hydrocarbon Compositional And Quality Determination
Author(s): David Wofford
Abstract/Introduction:
So what does this little parable teach us? First of all, a bad attitude at the bar is not endearing to good service and making friends. Secondly, chemistry jokes are only funny to a narrowly targeted audience. But more appropriate to the topic of discussion, products are valued differently based upon their phases, uses, behaviors and applications so the precise sampling and measurement of hydrocarbons are critical to optimizing economic value.
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Document ID:
309DA9BB
Basics For New ENGINEERING/PROJECT Managers
Author(s): Brad Massey
Abstract/Introduction:
Many individuals challenged with the task of installing gas sampling or analytical equipment for the first time typically dont have any background or formal training in the science of collecting, conditioning and transporting a representative sample to the end device. Often times, lacking the required knowledge to design, procure and install the equipment, the Design Rookie will listen and accept guidance from almost anyone that speaks with some confidence or authority on the subject. Keep in mind that the requestor was most likely given this task often times as an afterthought to a larger and much broader project. Therefore, they are instructed to get the equipment ordered and installed quickly and within budget. This approach will most usually end up either in a poorly designed and installed system, resulting in inaccurate analytical results or a system that is over designed and extremely costly. With minimal research and by following a few basic steps, the correct guidance can be found and easily followed for a correctly designed sample conditioning and transport system.
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Document ID:
16F2F44E
A Case For And An Update To Research And Testing On The Issue Of Hydrocarbon Wet Gas Sampling
Author(s): David J. Fish
Abstract/Introduction:
In the last 25 years, the natural gas pipeline industry has transitioned from the supplier of clean, dry gas to the mover of billable gas energy clean and dry or dirty and wet. The amount of hydrocarbon product that is transported between producer, processor, distributor and user is significant. To be able to verify the exact composition of the product is important from an economic and product treatment standpoint. In addition, if the best sampling procedures are followed, the potential for disputes between supplier and customer will be greatly reduced. The importance of properly determining hydrocarbon gas composition benefits all parties involved
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Document ID:
B7336752
Dynamics Of Vapor-Liquid Equilibrium In Pressurized Liquefied Calibration Standards
Author(s): Daniel Bartel
Abstract/Introduction:
Pressurized liquid calibration standards are use in many points of the petrochemical refining process. They are used to evaluate incoming material, monitor process streams, assay final product purity, etc... These liquefied calibration standards are packaged in one of three ways: 1. In a floating piston cylinder pressurized above the bubble point of the mixture. 2. In a normal gas cylinder at saturation pressure. 3. In a normal gas cylinder pressurized using a helium pressurization gas, typically at 200 psig. Floating Piston cylinders have two chambers, separated by a floating piston. The sample gas is contained on one side of the piston the pressurization gas on the other side. Floating Piston cylinders are usually used when non- condensable gases such as methane, nitrogen or carbon monoxide, are to be assayed in a liquefied gas sample. Floating piston cylinders are the ideal cylinders for pressurized liquefied mixtures. There is no interaction between the liquefied sample gas and the pressurization gas and the sample can be pressurized well above the bubble point of the mixture.
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Document ID:
7E236284
Techniques Of Composite & Spot Gas Sampling
Author(s): Royce Miller
Abstract/Introduction:
A sample should be taken on the longest piece of pipeline available. Unfortunately this is usually a meter tube. Not that this is a bad place to take a sample, but swirls can be created inside a meter tube. This can cause the flowing stream to create aerosols from the liquid collecting on the walls of the pipeline. The aerosols can be picked up by the sample causing a higher BTU reading.
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Document ID:
FD04BFE1
Wet Gas Sampling
Author(s): Jay St. Amant
Abstract/Introduction:
Natural Gas sampling has progressed from a rote, mechanical, blind art without qualified data to support it....to a better understood application of science in the 2005 and 2006 revisions of our industry standards. With those revisions came an understanding of limitations of technology and an application of basic physics and chemistry. The same vapor-liquid equilibrium, composition, temperature and pressure relationships that have been understood in the process world for many years were applied to the sampling world. It was at that time that our industry began moving from just being able to obtain a natural gas sample that could be analyzed (one that would not harm the analyzer) ...to being able to obtain analytically correct natural gas samples.
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Document ID:
C7C5F7DF
Yesterday Is Gone
Author(s): Gary W. Hines
Abstract/Introduction:
She accepted. As I sat and listened to those words, I had a small sense of surprise. The actual acceptance of the job at the Southern Gas Association was not what surprised me. I felt confident we had hired the right person and felt we had been genuine about describing our culture and the actual job requirements. No, what surprised me was how we found the applicant. I knew that LinkedIn was a toolset to allow business professionals to meet one another and to network with others through peer networks. I knew that there were people that moved in and out of jobs and careers in the LinkedIn world and that people would rely on their developed network to hopefully find their next job. No - what surprised me was that I, a Generation Xer, used the tool to assist in finding one of our newest employees.
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Document ID:
1D0C43CA
Cng Sampling
Author(s): Darin L. George
Abstract/Introduction:
Recent advances in natural gas production methods, particularly hydraulic fracturing, have led to increased gas reserves and lower natural gas prices in the United States. These factors have encouraged the use of compressed natural gas (CNG) as an alternative fuel for commercial vehicles and light-duty personal vehicles. Natural gas is expected to be the fastest-growing fuel in the transportation sector, with an expected average annual growth rate of almost 12% per year between now and the year 2040. Natural gas vehicles (NGVs) are attractive because of the low price of CNG on an energy-equivalent basis relative to gasoline, and because of the lower greenhouse gas emissions of CNG compared to gasoline and diesel fuels. In several cities, passenger NGVs have been granted access to HOV lanes to encourage their use as personal vehicles.
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Document ID:
1E7B3AE0