Sacrificial Anode Assembly for ESP Seal Section H2S Corrosion

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Solution Overview

Problem

Electric submersible pumps (ESPs) in wells with hydrogen sulfide (H2S) gas face corrosion issues due to H2S infiltration into the seal section, which can damage the electric motor and reduce the operational life of the completion string.

Innovation Solution

A novel seal section incorporating a sacrificial anode assembly with a sacrificial anode body made of reactive materials like copper, bronze, or aluminum, which reacts with H2S gas to neutralize its corrosive effects, thereby protecting the completion string components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional seal section is used without sacrificial anode, then the structure is simpler and cost is lower, but the electric motor and completion string components are damaged by H2S corrosion

Engineering Contradiction:

Improveprotection against H2S corrosionVSAvoidseal section structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sacrificial anode body acts as an intermediary between the H2S corrosive fluid and the completion string components. It chemically reacts with H2S to neutralize its corrosive effects, protecting the electric motor and other components from damage while being consumed in the process.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sacrificial anode body is designed as a consumable component that is relatively inexpensive compared to the electric motor and completion string. It is intentionally designed to be consumed over time as it reacts with H2S, extending the operational life of the expensive components it protects.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Duration of action of stationary object

If a sacrificial anode assembly is added to the seal section, then the operational life of completion string is extended, but the device complexity and initial cost increase

Engineering Contradiction:

Improveoperational life of completion stringVSAvoidseal section structure

Core Design Contradiction:

Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The sacrificial anode body is installed in advance within the seal section, positioned to intercept H2S fluid before it can reach and damage the electric motor and completion string components. This preliminary protective action occurs automatically as fluid flows through the seal section.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sacrificial anode assembly is nested within the existing seal section structure. The containment holds the sacrificial anode body inside the seal section, integrating the protection mechanism into the existing pump architecture without requiring complete structural redesign.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If sacrificial material is placed in direct contact with H2S fluid, then corrosion protection is maximized, but debris from material degradation may contaminate the wellbore

Engineering Contradiction:

Improvecorrosion protection effectivenessVSAvoiddebris contamination

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sacrificial anode body is extracted from direct contact with the production fluid stream by enclosing it within a containment. This allows the sacrificial material to react with H2S that diffuses through the containment wall, while preventing solid debris from entering the wellbore production flow.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The containment acts as a barrier shell that allows H2S gas to diffuse through to reach the sacrificial anode body while blocking larger particles and debris. This thin film approach enables selective permeability - allowing protective chemical reactions while preventing contamination.

Inventive Principle:

Principle #30Flexible shells and thin films

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 use of the sacrificial anode assembly effectively neutralizes the corrosive action of H2S gas, extending the operational life of the completion string by preventing damage to the electric motor and other components.

Implementation Method 1

A sacrificial anode body made of reactive materials like copper, bronze, or aluminum, which reacts with H2S gas to neutralize its corrosive effects

Methodology Applied

Scientific EffectSacrificial anode reaction: Redox Reactions

Data Source

PatentUS12215707B2Sacrificial anode assembly for a seal section of an electric submersible pump (ESP) assembly

Publication Date: 2025.02.04 HALLIBURTON ENERGY SERVICES INC

AI summary

An electric submersible pump (ESP) assembly. The ESP assembly comprises a seal section that comprises a housing and at least one sacrificial anode assembly. The at least one sacrificial anode assembly comprises a sacrificial material suitable to attenuate the corrosive effect of H2S fluid (hydrogen sulfide) and comprises a containment disposed inside the housing. The containment defines an annulus between an outside of the containment and an inside of the housing. The containment is disposed around the sacrificial material. The containment defines interiorly an initially void space downhole of the sacrificial material. The at least one sacrificial anode assembly defines a folded fluid flow path through the sacrificial material.