Abstract: A flameless nitrogen vaporizing unit includes a first internal combustion engine driving a nitrogen pump through a transmission. A second internal combustion engine drives three hydraulic oil pumps against a variable back pressure so that a variable load may be imposed upon the second engine. Liquid nitrogen is pumped from the nitrogen pump driven by the first engine into a first heat exchanger where heat is transferred from exhaust gases from the first and second internal combustion engines to the liquid nitrogen to cause the nitrogen to be transformed into a gaseous state. The gaseous nitrogen then flows into a second heat exchanger where it is superheated by an engine coolant fluid to heat the gaseous nitrogen to essentially an ambient temperature. The superheated nitrogen is then injected into the well. The engine coolant fluid flows in a coolant circulation system. Heat is transferred to the coolant fluid directly from the internal combustion engine.

Abstract: An automatic material sampling apparatus includes a housing for receiving a positively or negatively pressurized flow of material to be sampled as the material flows through a conduit, wherein the housing is disposed in-line with the conduit. The apparatus also includes a sampler mechanism for collecting a full cross-sectional sample of the material as the material flows through the housing under positive or negative pressure. The sampler means includes a collection member for receiving the sample and a movement mechanism for moving the collection member to collect or sweep out the full cross-sectional sample of the material. Movement of the collection member can be linear, arcuate or rotational or a combination of directions in different described embodiments of the apparatus.

Abstract: The present invention comprises a hydra-pneumatic load sensor and signal system including two stacked bellows, one filled with liquid, the other with a pressurized gas. Load on the sensor is initially supported by the gas filled bellows to a predetermined limit, above which the liquid filled bellows generates a liquid pressure signal which is used with a readout or control device.

Abstract: A flameless nitrogen vaporizing unit includes a first internal combustion engine driving a nitrogen pump through a transmission. A second internal combustion engine drives three hydraulic oil pumps against a variable back pressure so that a variable load may be imposed upon the second engine. Liquid nitrogen is pumped from the nitrogen pump driven by the first engine into a first heat exchanger where heat is transferred from exhaust gases from the first and second internal combustion engines to the liquid nitrogen to cause the nitrogen to be transformed into a gaseous state. The gaseous nitrogen than flows into a second heat exchanger where it is superheated by an engine coolant fluid to heat the gaseous nitrogen to essentially an ambient temperature. The superheated nitrogen is then injected into the well. The engine coolant fluid flows in a coolant circulation system. Heat is transferred to the coolant fluid directly from the internal combustion engine.

Abstract: A flameless nitrogen vaporizing unit includes a first internal combustion engine driving a nitrogen pump through a transmission. Connected to the transmission is a transmission retarder for varying the load on the first internal combustion engine by varying a level of hydraulic fluid present in the transmission retarder. A second internal combustion engine drives three hydraulic oil pumps against a variable back pressure so that a variable load may be imposed upon the second engine. Liquid nitrogen is pumped from the nitrogen pump driven by the first engine into a first heat exchanger where heat is transferred from exhaust gases from the first and second internal combustion engines to the liquid nitrogen to cause the nitrogen to be transformed into a gaseous state. The gaseous nitrogen then flows into a second heat exchanger where it is superheated by an engine coolant fluid to heat the gaseous nitrogen to essentially an ambient temperature. The superheated nitrogen is then injected into the well.