Triethanolamine Cement Accelerator for Wellbore Corrosion Control

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Solution Overview

Problem

Conventional cement compositions used for top job cementing, which include calcium chloride or other salts as accelerants, accelerate the cure rate but increase the corrosion rate of tubular strings and other metal components in wellbores, leading to reduced lifespan and costly repairs.

Innovation Solution

The use of an accelerated cement composition containing triethanolamine (TEA) as an accelerant, with a concentration greater than 10,000 parts per million, which not only accelerates the curing process but also forms a protective layer on metal surfaces to inhibit corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If calcium chloride or other salts are used as accelerants in cement composition, then the cure rate is increased and setting time is reduced, but the corrosion rate of tubular strings and metal components increases

Engineering Contradiction:

Improvecure rateVSAvoidcorrosion rate

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameter of the accelerant from calcium chloride (inorganic salt) to triethanolamine (organic amine). This parameter change maintains the acceleration function while eliminating the harmful corrosion effect, as triethanolamine forms a protective film on metal surfaces rather than promoting corrosion

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of accelerants causing corrosion into a benefit by selecting triethanolamine, which not only accelerates curing but also provides corrosion protection. The harmful effect of traditional accelerants is transformed into a beneficial dual-function accelerant that protects metal components

Inventive Principle:

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

2Loss of time

If conventional cement composition with salt accelerants is used for top job cementing, then the setting time is reduced, but the lifespan of wellbore components decreases due to increased corrosion

Engineering Contradiction:

Improvesetting timeVSAvoidlifespan

Core Design Contradiction:

Loss of timeVSDuration of action of stationary object

Solution Approach 1:

The patent changes the chemical composition parameter from salt-based accelerants to triethanolamine-based accelerant, achieving both faster setting time and extended lifespan by eliminating corrosion while maintaining acceleration effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite cement composition that integrates the accelerant function and corrosion protection function into a single material system. The triethanolamine component serves dual purposes: accelerating cement setting and forming a protective barrier on metal surfaces, thereby extending component lifespan

Inventive Principle:

Principle #40Composite materials

3Loss of time

If calcium chloride is used as accelerant, then the cure time is shortened, but maintenance costs increase due to corrosion damage

Engineering Contradiction:

Improvecure timeVSAvoidmaintenance costs

Core Design Contradiction:

Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful corrosion effect into a beneficial protection effect by using triethanolamine. The same accelerant that reduces cure time also forms a protective film on metal surfaces, preventing corrosion and thereby reducing maintenance costs

Inventive Principle:

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

Solution Approach 2:

The patent makes the accelerant multi-functional by selecting triethanolamine that performs both acceleration of curing and protection of metal surfaces. This universal accelerant eliminates the need for separate corrosion inhibitors and reduces overall maintenance requirements

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 accelerated cement composition with triethanolamine effectively reduces corrosion of tubular strings and other metal components while maintaining a fast cure time, thereby extending the wellbore's lifespan and reducing maintenance costs.

Implementation Method 1

the triethanolamine reacts with a metal of the tubular string to form a protective layer on the surface of the tubular string that inhibits corrosion

Methodology Applied

Scientific EffectChemical reaction forming protective layer: Chemical Bonding

Implementation Method 2

The triethanolamine acts as an accelerant to increase the cure rate of the accelerated cement composition

Methodology Applied

Scientific EffectChemical acceleration of curing: Catalysis

Data Source

PatentUS11773310B2Accelerated cement composition for reducing corrosion of wellbore casings

Publication Date: 2023.10.03 SAUDI ARABIAN OIL CO

AI summary

A method of reducing corrosion in tubular strings installed in wellbores includes dispensing an accelerated cement composition into a wellbore annulus, a casing-casing annulus, or both, the accelerated cement composition comprising a cement composition and an accelerant composition, where: the cement composition comprises a cement precursor and water; the accelerant composition comprises triethanolamine; and a concentration of the triethanolamine in the accelerated cement composition is greater than or equal to 10,000 parts per million by weight; allowing the accelerated cement composition to cure in the annulus to form a cured cement, where the triethanolamine reacts with a metal of the tubular string, the reaction forming a protective layer on the surfaces of the tubular string that inhibits dissolution of iron from the metal of the tubular string.