Subsea ESP Motor Inductive Heating for Viscous Fluid Startup

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Solution Overview

Problem

Submersible pumping systems face difficulties in starting up after shutdown due to high viscosity of crude oil and hydrate accumulation when fluids are cooled, leading to resistance issues and pump locking, which existing technologies fail to address effectively.

Innovation Solution

The method involves inductively heating the pump motor of an ESP system using altered electrical power supply, transferring heat energy to the fluid through a heat transfer system, and adjusting power delivery based on temperature sensing to reduce fluid viscosity and facilitate pump operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the pump is operated in cold sea water environment, then the pump can handle high temperature production fluids, but the fluid viscosity increases and hydrates accumulate causing pump locking

Engineering Contradiction:

Improveproduction fluid temperatureVSAvoidpump operability after shutdown

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The system performs preliminary heating of the production fluid using the motor as a heat source before pumping begins. This pre-heating action reduces fluid viscosity and prevents hydrate formation in advance, ensuring the pump can start successfully after shutdown in cold environments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention converts the harmful cold sea water environment into a beneficial heating source by using the motor windings as an inductive heating element. The electrical energy that would normally only drive the motor is instead used to generate heat through inductive heating, warming the fluid and preventing viscosity-related startup problems

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Temperature

If electrical power is supplied to heat the fluid, then fluid viscosity is reduced, but additional energy consumption is required

Engineering Contradiction:

Improvefluid temperatureVSAvoidenergy consumption for heating

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The motor serves dual functions: it acts as both the pumping drive and the heating element. By utilizing the motor windings for inductive heating during startup or low-flow conditions, the system eliminates the need for separate heating devices, thereby avoiding additional energy consumption and reducing overall system complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own motor as the heating source, making the heating function self-contained. The motor's electromagnetic field generates heat inductively within its windings, which is then transferred to the fluid, allowing the system to warm the fluid without requiring external heating equipment or additional energy inputs

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If the motor is used for inductive heating, then the motor structure is utilized efficiently, but the motor may be damaged by excessive heat

Engineering Contradiction:

Improvesystem simplicityVSAvoidmotor durability

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The system incorporates temperature sensing and control mechanisms that continuously monitor the motor and fluid temperatures. Based on this feedback, the control system adjusts the inductive heating power to maintain temperatures within safe operating limits, preventing motor damage while ensuring effective fluid heating for viscosity reduction

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The heating process is dynamically controlled rather than static. The system adjusts heating intensity based on real-time conditions such as fluid temperature, viscosity requirements, and motor thermal state. This dynamic control allows the motor to operate in heating mode temporarily without sustaining damage, as the heating is modulated to prevent excessive temperature accumulation

Inventive Principle:

Principle #15Dynamics

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

This approach enhances fluid flow by reducing viscosity and preventing hydrate accumulation, allowing for successful restart and continuous operation of the pumping system even in cold sea water environments.

Implementation Method 1

inductively heating the pump motor to generate heat energy

Methodology Applied

Scientific EffectInductive heating: Induction Heating

Implementation Method 2

transferring the generated heat energy from the pump motor can be accomplished using working fluid sealed in a heat transfer system

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

working fluid that circulates through the lower liquid portion, the tubes, and the upper/vaporization portion

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS8037936B2Method of heating sub sea ESP pumping system

Publication Date: 2011.10.18 BAKER HUGHES CO

AI summary

A system and method is provided for heating fluid to be pumped by an electrical submersible pumping system. Heat for heating the fluid may be inductively generated by adjusting the power delivered to the motor of the pumping system. In one example, the power adjustment includes supplying the voltage applied to the pump motor to a value less than voltage applied during normal operations. While lowering the voltage the electrical frequency may be varied as well as the electrical waveform.