Abstract: A standing valve which may be retrievably mounted in a well production tubing and will allow the maximum possible fluid flow and also allow the valve to be easily drained and retrieved through the well production tubing. The seal between the standing valve and the bottom hole assembly is located at or below the level of the seat and fluid from the top of the valve into the well is drained through the seat.

Abstract: This invention effects a significant reduction in leakage along a piston reciprocating in a cylinder and having a high fluid pressure differential existing between one end of the piston and the other. A large number of closely spaced, annular grooves are provided on the periphery of the piston and the clearance between the non-grooved piston diameter and the interior wall of the cylinder is maintained at a value significantly larger than that commonly employed between a smooth cylindrical shaft and a cylindrical interior sealing surface. The employment of such unexpectedly large clearance not only provides reduced fluid leakage for lighter density fluids when the equipment is relatively new, but the leakage becomes substantially less than that encountered in a smooth surface bearing construction as the piston and cylinder surfaces wear and increase the clearance.

Abstract: A petroleum well has a plurality of centrifugal pump stages, a jet pump stage, and an electrical drive motor. A recirculated portion of the output from high pressure stages of the centrifugal pump provides power fluid for the jet pump, and the jet pump aspirates fluid from lower pressure centrifugal pump stages. The balance of the output of the high pressure stages goes to the surface as production. The output of the jet pump supplies the high pressure stages. A centrifugal cleaner upstream of the power fluid inlet for the jet pump cleans that stream of particulates. The overall flow rate through the centrifugal stages exceeds the production rate of the pump by the amount of power fluid for the jet pump. The jet pump caps the assembly and can be separately removed for servicing and adapting the pump to the flow requirements of the well.

Abstract: This invention provides an improved jet pump having a Venturi chamber defined by a coating of a ceramic or alloy material that is highly resistant to both stress and erosion. The coating is applied by the chemical vapor technique upon a heated substrate of graphite. The graphite is then removed to conform in configuration to that of the coating and reduce the graphite substrate to a thickness of less than 0.010 inches. A mass of low melting, high elastic modulus material is then cast around the graphite substrate with the coating adhered thereto to define an exterior cylindrical configuration. The cylindrical mass is then encased by heat shrinking within a jacket of steel or other similar low modulus, high tensile strength material so as to produce a significant compressive force in the coating.

Abstract: While in a well, a downhole turbo-machine of a series of turbine stages and pump stages is driven by power fluid circulated into the turbine stages from the surface. A branch stream from the power fluid passes through a centrifugal cleaner and is cleansed of solid material. The turbine stages drive the centrifugal cleaner. The cleansed stream becomes lubricant for the turbo-machine bearings. On the turbine side, the lubricant stream passes at substantially cleaner discharge pressure into longitudinal passages between turbine shrouds and an alignment tube to journal bearings and journals located between turbine stage stators and a drive shaft driven by the turbines. Annular channels between separate shrouds effect communication between the longitudinal passages between the shrouds and the alignment tube. On the pump side, the lubricant stream is first directed so that it can act on a thrust bearing runner and apply a force in opposition to an otherwise unbalanced axial force.

Abstract: A jet pump has a nozzle for a power fluid, a Venturi for the power fluid and a well fluid, and a passage for the well fluid radially outside the Venturi and into the discharge of the nozzle. The power fluid aspirates the well fluid and the combined stream enters the Venturi. The Venturi is ceramic for erosion control. A shell sheaths the ceramic throughout its length and loads the ceramic compressively to provide a compressive preload on it. This preload opposes radial, outward acting stress in the Venturi arising from a greater fluid pressure within the Venturi than the fluid pressure outside it. The preload also produces a friction lock to keep the Venturi from sliding out of the shell because of an axial pressure differential.

Abstract: An articulated, submersible turbine pump for installation in a vertically elongated bottom hole assembly of a well has a flexible shaft and a plurality of rotor elements and stator elements mounted about the shaft in adjacent alternating relationship. Each rotor element has rotatable blades attached to the shaft by a hub and a housing segment surrounding the rotatable blades in outwardly spaced relationship therefrom to provide clearance for rotation. Each stator element has a close fitting hub around the shaft, which serves as a journal bearing, a housing segment outwardly spaced from the hub, and stationary blades attached between the hub and the housing segment. The housing segments are longer than the blades and the hub. Matching conical surfaces are formed at opposite ends of the housing segments to seal adjacent housing segments when axially aligned. An annular relief on the periphery of one of the surfaces permits the housing segments to pivot out of axial alignment when the shaft bends.