Double-disc straight blade impeller for subsea mud lift pump

Abstract

The invention relates to a double-disc straight blade impeller for a subsea mud lift pump. The impeller is characterized by comprising a ring-shaped driving wheel, wherein two lateral surfaces of the driving wheel are radially and symmetrically provided with a plurality of same radial straight blades, the ring center of the driving wheel is provided with a hub, four long blades are uniformly arranged on the hub at intervals, and each long blade is integrated with the corresponding radial straight blade on the two lateral surfaces of the driving wheel; the four long blades on one side of the driving wheel are provided with a connecting arm respectively, and the driving wheel is connected with a ring-shaped driven gear through the four connecting arms; and the two lateral surfaces of the driven gear are radially and symmetrically provided with a plurality of same radial straight blades. The impeller has strong multi-phase conveying capability, blockage resistance, abrasion resistance, flat flow lift curve, wide working range, small axial force and no sealing pressure, so the impeller can be widely applied to the subsea mud lift pump in a partition-free water pipe well drilling process.

Description

technical field [0001] The invention relates to a fluid conveying machine for conveying drilling mud and other seabed mineral particles, in particular to a double-disc straight blade impeller used for a seabed mud lift pump in the riserless drilling process. Background technique [0002] Riserless mud recovery drilling technology is a realization of dual-gradient drilling technology. Different from other dual-gradient drilling system solutions, the riserless drilling technology uses dual-gradient mud, and the subsea wellhead pressure is controlled close to seawater by subsea mud lift pumps. Hydrostatic pressure enables dual-gradient drilling. In this system, the drilling fluid is pumped into the drill pipe from the sea surface, reaches the bottom of the well through the drill pipe, impacts and breaks the rock and carries cuttings back up the wellbore annulus, and enters the subsea mud lift pump through the rotary diverter device at the top of the annulus , cuttings and dril...

AI Technical Summary

Problems solved by technology

At present, there are three shortcomings in the multi-stage centrifugal pump with semi-open impeller structure for high head. The slurry pump is basically used for the transportation of small-sized (particle size ≤ 3mm) solid particles; the second is that the multi-stage impeller structure of the centrifugal pump has high lift and large axial force, which requires an axial force balance device, which makes the structure of the pump complicated; The third is that the pressure of the final shaft seal of the multi-stage impeller structure is high, and the mechanical seal method needs to consider the flushing of the sealing surface. The structure of the deep-sea subsea application is more complicated, so the operating cost is high and the reliability is not ideal.

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