摘要 |
<p>A gas analysis system for determining the gas content of subterranean strata is disclosed. A boring operation is commenced to form a borehole (1) into or through a subterranean formation (4), such as a coal or shale formation to determine the gas content thereof. The drill fluid, cuttings and any desorbed gas is carried from the down-hole location to surface analysing equipment (18-44) in a closed system (14-17), so that the desorbed gases are not exposed to the air. The drill stem (3) is capped (10) or sealed at the surface, as well as the wellbore annulus to effectively seal the drill liquid, cuttings and desorbed gasses. The drill fluid, cuttings and desorbed gasses from the formation are coupled from the wellhead apparatus to the gas processing equipment via a closed system so that the constituents and volume of the gas can be determined without contamination from the atmospheric air.</p> |