Abstract: A gas gun is provided for generation of an acoustic pulse and subsequent detection of return reflections from the annulus of a well. The system includes a gas gun and a hand-held gas source. The hand-held gas source comprises: a two-part housing forming a chamber for receipt of a small CO.sub.2 gas cartridge commonly used for CO.sub.2 target pistols; means for piercing the gas cartridge and pressurizing the chamber; a coupling for releasable connection to a delivery assembly; a passageway leading from the chamber to the coupling; and a first valve in the passageway for controlling release of gas from the chamber.

Abstract: A well collar counting methodology is provided comprising first obtaining acoustic pulse data from a well and then digitizing and storing the amplitude-versus-time signal for subsequent processing. The raw signal is processed by applying a Wavelet Transform thereto for producing multiple resolutions of the signal, preferably four, at least one of which has a transformed signal resolution sufficient to distinguish reflections emanating from collars, and one of the coarser resolutions having a transformed signal resolution sufficient to distinguish reflections emanating from the fluid surface as kicks. The fluid surface kick and repeat kicks are determined by performing multi-resolutional analysis of each maximum, at the coarser resolution, as synchronized against the successively finer resolutions and compared as being significant with respect to adjacent maximums.

Abstract: In a well using a lift pump operated by a tension string from the surface, the down stroke of the pump is accelerated by providing a plunger element secured to the pump operating string. The plunger has an upper end exposed to the high hydrostatic pressure in the tubing string above the pump, and a lower end exposed to the substantially lower hydrostatic pressure in the well outside the tubing string. This produces a net downwards force on the pump operating string allowing a higher pump speed and a higher volume delivery.