Multistage blade mud pump for riserless subsea mudlift drilling

Abstract

The invention discloses a multistage blade mud pump for riserless subsea mudlift drilling. The multistage blade mud pump comprises driving impeller cover plates, driven impeller cover plates, radial blades, guide vanes, a driving shaft and the like. The radial blades are arranged between the driving impeller cover plates and the driven impeller cover plates and are discontinuous, namely a bladeless area is present; the driving impeller cover plates and the driven impeller cover plates are connected through connecting arms; inlet sections of the driving impeller cover plates and the driven impeller cover plates are properly transited to the radial direction in an arc form or a conical form; and a fluid medium is guided to the next stage of impeller through a guide vane. The multistage blade mud pump can deliver multi-phase flow media, is not blocked, and is wear-resistant and high in lift; and a flow-lift performance curve is flat, a working range is wide and the requirement on mechanical sealing property is low.

Description

technical field [0001] The invention relates to the field of fluid conveying machinery, in particular to a multi-stage vane mud pump for lifting drilling mud on the seabed without a riser, which is suitable for conveying drilling mud and other seabed mineral particles on the seabed. Background technique [0002] Riserless mud recovery drilling technology is a realization of dual-gradient drilling technology. The difference from other dual-gradient drilling technologies is that the mud and cuttings returned to the riserless drilling system are returned to the sea surface through the suction module through the subsea mud lift pump, and Pressure control realizes dual-gradient drilling. At present, the return of mud in the riserless drilling system is mainly realized by the series connection of the mud lift pump, and as the water depth increases, the number of series modules of the pump increases, which reduces the reliability and maintainability of the lift pump module; The sp...

AI Technical Summary

Problems solved by technology

At present, the return of mud in the riserless drilling system is mainly realized by the series connection of mud lift pumps, and as the water depth increases, the number of series modules of the pump increases, which reduces the reliability and maintainability of the lift pump modules; The special working environment of the lift pump and the conveying medium put forward special requirements for the lift pump: 1) Since drilling cuttings and mud need to be returned to the sea surface through the subsea lift pump, the lifting pump lift is required to be high enough; 2) Because the conveying medium is highly abrasive Particles, or even drilling fluid containing a large amount of gas, require the lift pump to have the ability to resist clogging, wear resistance and multi-phase transportation; 3) Under the conditions of deep water and high head, it has the ability of solid-liquid two-phase flow without external flushing device Leak-free sealing performance

[0003] At present, multi-stage centrifugal pumps have certain advantages in axial force balance and pump head improvement; when transporting high-viscosity, high-concentration and fluid media containing solid particles, they have low efficiency, easy wear, and poor reliability when used on the seabed.

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