Abstract: A method for the circulation of gas when drilling or working a well. The method includes the step of pressurizing at least two chambers of a multi-chambered accumulator with inert gas. The chambers of the multi-chambered accumulator are operatively connected to one another and individually or in combination isolatable from each other. The method also includes isolating at least one chamber of the accumulator that has been pressurized with inert gas such that during drilling or working the well the isolated chamber remains pressurized with gas that has not been mixed with well gas returns. Pressurized gas is extracted from one or more of the non-isolated chambers of the accumulator and injected into the well. At least a portion of the gas returns from the well is collected, compressed and delivered to at least one of the non-isolated chambers of the multi-chamber accumulator.

Abstract: Disclosed is an apparatus for producing a pressurized stream of substantially inert gas. The apparatus includes a compressor having an intake manifold and an output manifold. The intake manifold receives a substantially inert gas stream and the output manifold receives a stream of pressurized gas from the compressor. The apparatus further includes a compressed gas re-circulation conduit connecting the output manifold to the intake manifold such that a portion of the pressurized gas from the compressor is re-circulated from the output manifold back to the intake manifold to maintain the gas pressure within the intake manifold above atmospheric pressure and to prevent atmospheric gases from being drawn into the intake manifold.

Abstract: Disclosed is a method of producing a pressurized stream of substantially inert gas. The method comprises collecting at least a portion of the exhaust gases from an internal combustion engine. The collected exhaust gases are directed into the intake of a compressor which compresses the exhaust gases such that the exhaust gases exit the compressor at a pressure that is above atmospheric pressure. A portion of the compressed exhaust gases are re-circulated back into the intake of the compressor. The re-circulated portion of the compressed exhaust gases are of a sufficient volume to maintain the pressure within the compressor intake above atmospheric pressure and to thereby prevent atmospheric gases from being drawn into the intake of the compressor and into the stream of substantially inert gas.

Abstract: A method and apparatus for controlling the operation of an internal combustion engine to reduce the presence of free oxygen in the exhaust gas of the engine. The method and apparatus provides for the internal combustion engine to be operated with a fuel-to-air ratio in excess of the stoichiometric ratio such that the exhaust gas from the internal combustion engine is devoid or substantially devoid of all free oxygen and excess unburned hydrocarbon fuel is expelled with the exhaust gas from the engine.

Abstract: Disclosed is a method of producing a pressurized stream of substantially inert gas. The method comprises collecting the exhaust gases from an internal combustion engine, directing the exhaust gases into the intake of a compressor for compressing to a desired pressure, and recirculating a portion of the compressed exhaust gases back to the intake of the compressor such that the pressure of the exhaust gases within said compressor intake is maintained above atmospheric pressure. Also disclosed is an apparatus for producing a pressurized stream of substantially inert gas utilizing the described method.

Abstract: A method and apparatus for controlling the operation of an internal combustion engine to reduce the presence of free oxygen in the exhaust gas of the engine. The method and apparatus provides for the internal combustion engine to be operated with a fuel-to-air ratio in excess of the stoichiometic ratio such that the exhaust gas from the internal combustion engine is devoid or substantially devoid of all free oxygen and excess unburned hydrocarbon fuel is expelled with the exhaust gas from the engine.

Abstract: Disclosed is a method of producing a pressurized stream of substantially inert gas. The method comprises collecting the exhaust gases from an internal combustion engine, directing the exhaust gases into the intake of a compressor for compressing to a desired pressure, and recirculating a portion of the compressed exhaust gases back to the intake of the compressor such that the pressure of the exhaust gases within said compressor intake is maintained above atmospheric pressure. Also disclosed is an apparatus for producing a pressurized stream of substantially inert gas utilizing the described method.