Because the composition of natural gas changes over time due to changes in the natural gas reservoir and other factors, there is a need to sample the gas to determine its composition. Sampling to determine the gas composition is important part of custody transfer and fiscal metering. Contracts are typically concerned with the BTU or energy content of the gas and the hydrocarbon dewpoint of the gas. There are many robust automatic gas sampling systems such as Gas Chromatographs (CGs) in the field that can perform on-line sampling. These are typically expensive, require frequent maintenance, and are usually only justified when large volumes of gas are being moved.
But what about low pressure, low producing wells or pipelines? The companies involved typically cannot justify on-line GCs or other automatic sampling systems, so in these cases, spot sampling is recommended. This means collecting a representative sample at a specific moment in time that can be taken to a laboratory for analysis.
The Ralston SP0V gas sampling pump helps make this process easier by helping to take a gas sample from a low pressure or low flow pipeline or well and putting it into a sample cylinder without changing the gas composition or reaching the hydrocarbon dewpoint.
The SP0V gas sampling pump is constructed in accordance with API 14.1 and GPA 2166. Materials of construction are hard anodized aluminum, stainless steel and has Viton seals and the pump is lubricated with hydrocarbon-free lubricant. All of these things help to prevent contamination of the sample as well as resisting H2S, mercury and other active compounds found in natural gas. To perform effective sampling that provides good representative gas composition data in cases where on-line GCs are not justified the Ralston SP0V gas sampling pump is an excellent new tool to help in this process.