Techniques Of Composite Sampling

Author: Joe SoosDownload File

Energy companies focused on natural gas production, gathering, transmission, or distribution are ultimately valued on their ability to produce or deliver natural gas to its customers. Pressure and temperature measurement provides data that is required to quantify natural gas flow rates while natural gas sampling provides the heat content, or energy value, associated with this natural gas. Accurate measurement and data collection is the foundation for natural gas purchase and sales contracts and royalty payments. The underlying data that support these contracts are the ultimate economic value drivers for these energy companies. This paper will focus on proper natural gas sampling techniques and methods, including proper installation and location of spot, composite, and continuous samplers connected to a gas chromatograph. Economic, regulatory, compositional, and contractual consideration must always be evaluated and taken into consideration when selecting sampling technique. Generally, samples should be collected on a flow-proportional or flow-weighted basis whenever practical. Spot samples, by their nature, cannot fully represent a gas stream of varying composition. Likewise, time proportional sampling, particularly when utilized during intermittent or slug flow,is not capable of accurately characterizing natural gas streams with variable flow rates or compositions