Natural Gas Sampling
This sampling method is devoted to natural gas using a vacuum or pressurized containers, which will be brought to the laboratory. Container chosen such that the gas composition has not changed during transport or during storage. This sampling procedure, used for the analysis of the composition of natural gas and the gas chromatography analysis also for another purpose. Particularly intended sampling procedure called wet gas sampling procedure, ie at pressures up to 1100 psi. In this sampling procedure was not described how sampling is called dry natural gas, which are limited by their sampling pressure.
Outline Methods
Samples of natural gas transferred from the source into the sample container with one of the following methods.
(A). Purging Procedure – Fill and Empty Method (B). Purging Procedure – Controlled Rate Method
(C). Evacuation Procedure containers
Methods are selected based on the composition of the sample, the pressure and temperature of the sample source and type of equipment used. This sampling method is categorized not as a kind of composite sample, but as spot samples, where samples were taken at intervals. It is possible that, when the moment of sampling or sample delivery, condensation will occur, therefore it is recommended that the sample container is heated at a temperature of 20-50 is higher than the temperature of the source.
Selection of Sampling Procedures
Sampling procedure can be classified into two types of samples of natural gas, which is wet natural gas and natural gas cleaning.
(A). Dry natural gas, the natural gas samples which do not form a condensate when cooling, caused by the expansion of the pressure source to atmospheric pressure or a certain pressure. Classified as dry natural gas when the pressure is less than 400 psi source.
(B). Wet natural gas, the natural gas sample that can form condensates during cooling, caused by the expansion of the pressure source to atmospheric pressure. Classified as wet natural gas when the pressure is above 400 psi source.
