Abstract: A sensor arrangement for determining at least one of gas constituents and gas concentrations of a gas mixture including oxidizable gas constituents includes a diffusion duct having a gas mixture gas orifice in communication with the gas mixture and having a reference gas orifice in communication with a reference gas; and a measuring element having a sensitive zone which is positioned in the diffusion duct, the sensitive zone being exposed to the gas mixture via the gas mixture gas orifice and being exposed to the reference gas via the reference gas orifice, wherein the reference gas and the gas mixture have respective oxygen partial pressures, and wherein the oxygen partial pressure of the reference gas is higher than the oxygen partial pressure of the gas mixture so that oxygen is present in the sensitive zone of the measuring element in amounts sufficient to oxidize the oxidizable gas constituents to be measured.

Abstract: A downhole inspection tool is attached to the lower end of a length of coiled tubing having an electrical/fiberoptic cable threaded through the center. The coiled tubing carries a flow of optically clear and/or acoustically homogeneous fluid from a supply of such fluid at the surface. The tool itself includes a cable head subassembly module attached to the lower end of the coiled tubing and terminates the electrical and optical conductors within the cable. An inspection module for producing an electrical signal indicative of downhole conditions is detachably connected to the lower end of the cable head assembly module. An outer flow tube is mechanically connected to the inspection module and surrounds both of the modules to define an annular space therebetween.

Abstract: A device for use in a method of detecting the permeability of an article to oxygen is disclosed. A redox indicator and test object are vacuum sealed between a support and a peelable barrier film.

Abstract: A wax appearance point in a petroleum produce is determined by measuring change in volume as a function of temperature. The appearance point appears as a deviation from a rectilinear graph. The quantity of wax which appears is determined by comparing a measured volume graph as a function of temperature with an estimated volume graph.

Abstract: A small sample of combustion engine lubrication oil is analyzed, simultaneously, for its viscosity and contamination level in a compact, self-contained, computer-controlled unit. If the combination of viscosity and contamination level falls outside of the acceptable range, which is determined by comparison to a digitally stored matrix of the various states of used motor oil, a warning is displayed recommending that the oil be changed.

Abstract: A method for testing physical integrity of production tubing and production casing in a gas-lift well includes the steps of opening communication from a pressure source to an interior space of the production tubing; disposing a sealing tool in the production tubing to obtain a seal at a desired location of the production tubing; opening communication from an inner annular space of the well; applying a predetermined test pressure to the interior space of the production tubing; monitoring the test pressure applied for a pressure drop; and monitoring flow from the inner annular space. The physical integrity of the production casing is then tested by opening communication from a pressure source to the inner annular space; closing communication from the interior space of the production tubing; applying a predetermined test pressure to the inner annular space; and monitoring the test pressure for a pressure drop.

Abstract: The borehole formation model is built by stacking in a spaced relationship selected glass plates to simulate the formation. Each glass plate has a circular hole in the center to simulate the oil or gas borehole. The hole can be sized in different sets to simulate various borehole diameters and for accommodating casing/cement sections for simulating cased boreholes. The glass plates are supported by plastic spacers. The spacers are sized to provide a matrix section having uniform distances between layers. The "stacked" glass/spacer matrix provides only glass for simulating the formation "pore space". The glass plates have a uniform thickness, and the porosity of the simulated formation can be changed by changing the thickness of the plastic spacers. After stacking the glass plates, a "borehole" is constructed by inserting a thin stainless steel tube through the center holes of the glass stack and sealed at the bottom.