Multistage Pump Segmentation for Downhole Assembly

Solution Overview

Problem

Existing multistage pumps for lifting multiphase fluids in hydrocarbon wells are complex to assemble, difficult to manufacture in large volumes, and challenging to maintain due to intricate component alignment and balancing requirements, which limits their scalability and reliability.

Innovation Solution

A multistage pump design featuring pre-assembled twin screw pump modules with discrete thrust bearings and adjustable rotor pairs, allowing for simpler assembly and alignment, reduced complexity in manufacturing, and enhanced reliability through redundancy in thrust and timing components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If multistage pumps are used to generate high differential pressures, then the pressure generation capability is improved, but the device complexity increases due to multiple pump stages and component alignment requirements

Engineering Contradiction:

Improvedifferential pressureVSAvoidpump stage configuration

Core Design Contradiction:

Stress or pressureVSDevice complexity

Solution Approach 1:

The pump is divided into multiple discrete pump stages, each capable of generating a portion of the total differential pressure. Each stage contains its own rotor assembly and thrust bearing, allowing independent assembly and maintenance while contributing to the overall high pressure generation capability when stages are connected in series.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If traditional twin screw pump designs are used, then the multiphase fluid handling capability is improved, but the manufacturing complexity increases due to intricate rotor alignment and thrust bearing configuration

Engineering Contradiction:

Improvemultiphase fluid handlingVSAvoidrotor alignment

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The pump is divided into multiple discrete pump stages, each capable of generating a portion of the total differential pressure. Each stage contains its own rotor assembly and thrust bearing, allowing independent assembly and maintenance while contributing to the overall high pressure generation capability when stages are connected in series.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Thrust bearings are pre-installed on the rotors before rotor assembly, establishing predetermined axial positions. This preliminary action eliminates the need for complex alignment procedures during final assembly, as the thrust bearings automatically position the rotors correctly when engaged with the stator.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If pumps are designed for downhole use in harsh environments, then the reliability in harsh environments is improved, but the ease of repair deteriorates due to difficult access for maintenance

Engineering Contradiction:

Improvedownhole operation reliabilityVSAvoidmaintenance accessibility

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The pump is divided into multiple discrete pump stages, each capable of generating a portion of the total differential pressure. Each stage contains its own rotor assembly and thrust bearing, allowing independent assembly and maintenance while contributing to the overall high pressure generation capability when stages are connected in series.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The modular stage design allows individual stages to be replaced as wear components rather than requiring complete pump replacement. Thrust bearings can be recovered and reused on rebuilt stages, reducing maintenance costs and improving ease of repair in remote downhole locations.

Inventive Principle:

Principle #34Discarding and recovering

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design facilitates quicker assembly, reduced manufacturing costs, and improved reliability by allowing for rapid production and maintenance of multistage pumps, enabling efficient handling of multiphase fluids and high differential pressures in harsh downhole environments.

Implementation Method 1

twin screw positive displacement pumps may reliably be used to produce multiphase fluids

Methodology Applied

Scientific EffectMechanical displacement:

Implementation Method 2

a first thrust bearing for the drive shaft and a second thrust bearing for the lay shaft

Methodology Applied

Scientific EffectThrust bearing support: Ball Bearing

Data Source

PatentEP2396507B1pump

Publication Date: 2019.12.18 BP EXPLORATION OPERATING CO LTD

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AI summary

A multistage pump (4) comprises: ° a plurality of components (50, 60, 70, 80, 90, 100, 110) comprising a plurality of pre-assembled pump modules (70, 90, 110) including at least one twin screw pump module (1, 2); characterised in that the multistage pump (4) further comprises an elongate sleeve (41) for housing the components (50, 60, 70, 80, 90, 100, 110); and securing means (42a, 42b) attachable or engagable with a portion of the elongate sleeve (41), the securing means (42a, 42b) being operable to fixedly retain the components (50, 60, 70, 80, 90, 100, 110) within the sleeve (41).