GB536982A - Soil gas sampling device and method - Google Patents

Abstract

536,982. Prospecting. FIFE, J. G. (Naamlooze Vennootschap de Bataafsche Petroleum Maatschappij.). Jan. 5, 1940, No. 277. [Class 85] In obtaining samples of gas from the ground for locating underground substances such as oil, a sampling zone is confined and maintained at a pressure below that of the atmosphere, and a second zone is confined between the sampling zone and the atmosphere and maintained at a pressure lower than that of the sampling zone to prevent contamination by atmospheric air. In Fig. 1, a sectional rod or tube 2, provided with bit 30 and head 1, is forced into the ground by pressure, percussion or block and tackle, and carries spaced packers 5, 15, adapted to isolate a sampling zone 23 below the packers and a guard zone 13 between the packers; the latter may be expansible and inflated by gas or liquid through a pump 60 and duct 9. The zones 13, 23, are connected through filter screens 12, 28, and ducts 6, 22, to a vacuum pump 63, valves 61, 62, controlling the relative pressures which are indicated by a manometer 58. The screen 28 may have a silk lining. The gas sample is received in a reservoir 57 which may be isolated by valves 50 51. In another form, the manometer 58 is connected by separate pipes to the zones 13, 23. In Fig. 2, packers 5, 15, which may be connected by a rod 80, are lowered into a pre-formed bore-hole. In Fig. 3, a container 73, connected to the sampling duct 22 through a filter 28, is driven into the ground, and the guard zone is formed by a rubber or treated canvas hood 72 which may have a suitable frame and is provided with an earth seal 75.