A submersible well pump has diffusers fixed within the housing and an impeller mounted between each of the diffusers. Spacer sleeves located between and in abutment with hubs of adjacent ones of the impellers define a stack wherein the impellers rotate in unison with the shaft and are axially movable in unison with each other relative to the shaft. A stop shoulder on the shaft abuts the lower end of the stack. A spring mounted in compression around the shaft in abutment with the upper end of the stack urges the lower end of the stack against the stop shoulder. Upward movement of the stack requires further compression of the spring. Up thrust and down thrust gaps between each impeller and adjacent diffusers prevent up thrust and down thrust from being transferred to any of the diffusers.

A submersible well pump has diffusers fixed within the housing and an impeller mounted between each of the diffusers. Spacer sleeves located between and in abutment with hubs of adjacent ones of the impellers define a stack wherein the impellers rotate in unison with the shaft and are axially movable in unison with each other relative to the shaft. A stop shoulder on the shaft abuts the lower end of the stack. A spring mounted in compression around the shaft in abutment with the upper end of the stack urges the lower end of the stack against the stop shoulder. Upward movement of the stack requires further compression of the spring. Up thrust and down thrust gaps between each impeller and adjacent diffusers prevent up thrust and down thrust from being transferred to any of the diffusers.

A bullhead-shaped grooved diversion jet and empennage swing vibration suppression device and method. The device consists of an impeller diversion module and a drainage rotary cover module. The impeller diversion module consists of a center impeller, sleeve bearings, small impellers, and small impeller rotating shafts. The drainage rotary cover module consists of a drainage front cover, a perforated jet rear cover, and empennages. The device is mounted on an outer wall of a riser in a sleeving manner. Under a combined action of drainage and space allocation of horizontal rectangular grooves, flow rate distribution of the center impeller, flow direction adjustment of the small impellers, diversion of lateral diversion holes, jet flows of side rear reducing holes, flowing space division and wake vortex turbulence of rotary swinging empennages, around-flow boundary layers at two sides and a tail of the riser are deeply damaged, which suppresses the formation of large vortexes.

A submersible well pump assembly has a motor that rotates a drive shaft within the pump. The pump has a number of pump stages, each stage having a diffuser and an impeller. A bushing is fixed for non-rotation within the diffuser. A thrust runner sleeve mounted to the drive shaft has an outer diameter surface in sliding rotating engagement with an inner diameter surface of the bushing. At least one seal ring is mounted to the sleeve in sealing engagement with the drive shaft to block the entry of well fluid particulates between the sleeve and the drive shaft.

A low profile pump motor lead protector with a head guard and a trailing guard, the head guard including a front section with a front end and a rear section with a rear end, the trailing guard having a pin end for insertion in a head guard socket, the lead protector for protecting a motor lead of a pump and motor assembly of a downhole production string for surfacing fluid from a reservoir such as a subterranean oil well.

A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.

A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.

Methods are provided to prepare a low sulfur fuel from hydrocarbon sources, such as light tight oil and high sulfur fuel oil, often less desired by conventional refiners, who split crude into a wide range of differing products and may prefer presence of wide ranges (C3 or C5 to C20 or higher) of hydrocarbons. These fuels can be produced by separating feeds into untreated and treated streams, and then recombining them. Such fuels can also be formulated by combinations of light, middle and heavy range constituents in a selected manner as claimed. Not only low in sulfur, the fuels of this invention are also low in nitrogen and essentially metals free. Fuel use applications include on-board large marine transport vessels but also on-shore for large land based combustion gas turbines, boilers, fired heaters and transport vehicles and trains.

A submersible well pump assembly has upper and lower seal sections connected between the pump and a motor. The seal sections have drive shafts with thrust runners that engage thrust bearing bases. The upper drive shaft will undergo a limited amount of downward movement toward the lower drive shaft in response to wear of the upper thrust bearing base. A spring between ends of the drive shafts transfers a portion of the down thrust on the upper drive shaft to the lower drive shaft prior to the limited amount of downward movement of the upper drive shaft toward the lower drive shaft being reached. A rigid stop member in the coupling transfers down thrust directly from the upper drive shaft to the lower drive shaft, bypassing the spring, only after the limited amount of downward movement of the upper drive shaft toward the lower drive shaft has been reached.

A centrifugal electric submersible pump (ESP). The centrifugal ESP comprises a rotatable shaft, a series of impellers stacked on the rotatable shaft, each impeller comprising a hub secured to the rotatable shaft by a key, the series of impellers comprising an uppermost impeller and a lowermost impeller, a flanged sleeve keyed to the rotatable shaft below the lowermost impeller, and a seal disposed between the lowermost impeller and the flanged sleeve.