A portable security system comprises two security units, located on opposite sides of a roadway or other path for vehicles, each consisting of at least two hollow barrier devices filled with a ballast material such as water, sand, chunks of rubber or the like. The machine is operate to read a financial card bearing account indicia with a card reader of the machine. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The present method is production of shallow crude oil by way of long horizontal or near horizontal boreholes drilled and serviced from a subsurface workroom. Either an undersurface of the annular flange or a mating surface of the valve housing is provided with a compressible sealing member while the other is provided with an annular edge.