Advances in exploration, drilling and production technologies make it feasible to extract natural gas from sources that in the past have been regarded as unconventional and so, such sources are becoming a larger percentage of the gas supply. The feasibility of producing gas from a source is the primary factor in determining whether that source should be categorized as conventional or unconventional. What has been unconventional in the past may be considered conventional in the future.

This paper will discuss gas sampling system design fundamentals and highlight key aspects of current industry standards. It will also explore the challenges associated with sampling gas from unconventional sources such as shale formations, deep-water offshore wells and enhanced recovery systems. Proper sampling of natural gas from unconventional sources usually requires equipment and techniques that are more sophisticated than those that have performed well for conventional gas sources. Methods for the continuous sampling of natural gas that is wet, at high pressure or even supercritical will be presented. The primary focus of this paper is on minimizing the error associated with sampling for compositional analysis. Sampling considerations associated with the measurement of single components will however also be discussed.