TCT Reduction Additives for High-Density Brine Crystallization

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Solution Overview

Problem

High-density, zinc-free, and cesium-free aqueous brine fluids used in drilling, completion, and workover operations face challenges due to high crystallization temperatures, which can lead to precipitation issues in cold weather or high-pressure conditions, making them unsuitable for certain applications.

Innovation Solution

The use of additives such as formamide, urea, ethylenediaminetetraacetic acid (EDTA), N-(Phosphonomethyl)iminodiacetic acid (PMIDA), tartaric acid, gluconic acid, citric acid, and malic acid to reduce the True Crystallization Temperature (TCT) of calcium bromide, calcium chloride, and manganese (II) bromide brines, allowing for the creation of fluids with densities greater than 14.2 lb/gal while maintaining operationally acceptable crystallization temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-density brines (density > 14.2 lb/gal) are used in drilling operations, then the fluid provides sufficient hydrostatic pressure and density requirements, but the crystallization temperature becomes too high causing precipitation in cold weather or high-pressure conditions

Engineering Contradiction:

ImprovedensityVSAvoidcrystallization temperature

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The patent changes the chemical composition parameters of the brine by adding specific additives (formamide, urea, EDTA, PMIDA, tartaric acid, gluconic acid, citric acid, or malic acid) to modify the crystallization temperature characteristic while maintaining the high density requirement. This allows the brine to remain liquid at lower temperatures where conventional high-density brines would precipitate.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite brine system by combining conventional high-density brine components (calcium bromide, calcium chloride, or manganese bromide) with TCT-reducing additives. This composite formulation achieves both high density and low crystallization temperature, resolving the contradiction between these two properties.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If conventional high-density brines are used, then density requirements are met, but precipitation occurs in cold weather or high-pressure conditions due to high crystallization temperature

Engineering Contradiction:

ImprovedensityVSAvoidprecipitation resistance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

By adding TCT-reducing additives, the patent changes the thermal parameters of the brine system, lowering the crystallization temperature from potentially above 0°F to below 0°F or even -20°F. This parameter change ensures the brine remains in liquid state under cold weather and high-pressure downhole conditions, eliminating precipitation issues.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The additives enable the brine to skip the phase transition from liquid to solid at the original crystallization temperature point. By modifying the crystallization behavior, the brine can be pumped and circulated through cold environments and high-pressure zones without undergoing precipitation, ensuring reliable operation.

Inventive Principle:

Principle #21Skipping (Rushing through)

3Temperature

If zinc or cesium are added to reduce crystallization temperature, then TCT is lowered, but the fluid becomes environmentally hazardous and requires special handling

Engineering Contradiction:

Improvecrystallization temperatureVSAvoidenvironmental hazard

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces expensive and hazardous zinc or cesium additives with cheaper, environmentally benign alternatives such as formamide, urea, EDTA, PMIDA, tartaric acid, gluconic acid, citric acid, or malic acid. These substitutes achieve the same TCT reduction effect without the environmental hazards and special handling requirements of zinc and cesium.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent introduces intermediary substances (the TCT-reducing additives) that mediate between the high-density brine and the environmental constraints. These intermediaries lower the crystallization temperature through chemical interaction with the brine components, providing an environmentally safe pathway to achieve low TCT without using hazardous metals.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 addition of these TCT reduction additives significantly lowers the crystallization temperature, enabling the use of high-density brines in a wider range of conditions without precipitation, thus addressing the limitations of existing high-density brines in drilling and completion operations.

Implementation Method 1

Methodology Applied

Scientific EffectColligative properties:

Data Source

PatentUS11001740B2Additives to reduce the crystallization temperature of brines and methods of use

Publication Date: 2021.05.11 HALLIBURTON ENERGY SERVICES INC

AI summary

A composition of a treatment fluid having an aqueous base fluid and a true crystallization temperature reduction additive. A method includes providing a treatment fluid having an aqueous base fluid, adding a true crystallization temperature reduction additive and placing the treatment fluid in a subterranean wellbore.