Rheology Modifying Additive for Cement Slurry Rheology

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Solution Overview

Problem

Current wellbore servicing compositions, particularly cement slurries, face challenges in achieving desirable rheological properties for effective displacement and sealing in subterranean formations, especially in eccentric wells, where the cement slurry's viscosity and flow resistance need to be optimized for efficient cementing operations.

Innovation Solution

Incorporating a rheology modifying additive (RMA) comprising a gum, such as xanthan gum, and a polymeric material, like AMPS polymer, into wellbore servicing compositions to enhance viscosity and flow characteristics, allowing for improved displacement and sealing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cement slurry is used without rheology modifying additives, then the composition is simple and easy to manufacture, but the rheological properties are insufficient for effective displacement and sealing in eccentric wells

Engineering Contradiction:

Improvedisplacement and sealing effectivenessVSAvoidcomposition complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining gum (natural polymer) and polymeric material (synthetic polymer) to create a rheology modifying additive that provides superior rheological properties compared to single-component additives. This composite approach enables the cement slurry to achieve desirable rheological characteristics for effective displacement and sealing while maintaining reasonable composition complexity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent utilizes parameter changes by adjusting the molecular weight, degree of branching, and concentration ratios of the gum and polymeric material to optimize the rheological properties of the cement slurry. By controlling these parameters, the formulation achieves enhanced yield point and plastic viscosity while maintaining pumpability and setting characteristics.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the cement slurry viscosity is increased to improve sealing, then sealing capability is enhanced, but the flow resistance increases and displacement becomes less efficient

Engineering Contradiction:

Improvesealing capabilityVSAvoiddisplacement efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by formulating a rheology modifying additive that enables the cement slurry to exhibit dynamic rheological behavior - maintaining low viscosity during pumping for efficient displacement, then transitioning to higher viscosity upon standing for effective sealing. The gum-polymer combination provides this dynamic response through their synergistic interaction with the cement particles.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses parameter changes by optimizing the molecular weight and concentration of the rheology modifying additive to achieve a balance between viscosity for sealing and flowability for displacement. The specific parameter ranges selected allow the slurry to maintain pumpability while achieving adequate sealing pressure.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If rheology modifying additives are added to improve rheological properties, then displacement and sealing performance is enhanced, but the manufacturing complexity and cost increase

Engineering Contradiction:

Improverheological performanceVSAvoidmanufacturing simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies the intermediary principle by using the gum-polymer additive as a mediator that modifies the interaction between cement particles and water. This intermediary substance controls the rheological properties without requiring complex manufacturing processes, simply requiring mixing of the additive into the cement slurry formulation.

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 RMA enhances the yield point and plastic viscosity of cement slurries, providing stable rheology and reduced fluid loss, enabling effective cementing and sealing in complex wellbore configurations, including eccentric wells, with tunable rheological properties for optimal performance.

Implementation Method 1

the rheology modifying additive enhances the yield point and plastic viscosity of cement slurries

Methodology Applied

Scientific EffectViscosity modification:

Implementation Method 2

Methodology Applied

Scientific EffectPolymer-cement interaction:

Implementation Method 3

providing stable rheology and reduced fluid loss

Methodology Applied

Scientific EffectFluid loss reduction:

Data Source

PatentUS9296939B2Compositions for modifying rheological properties of cement systems

Publication Date: 2016.03.29 HALLIBURTON ENERGY SERVICES INC

AI summary

A method of servicing a wellbore comprising contacting a wellbore servicing composition with a rheology modifying additive wherein the rheology modifying additive comprises a gum and a polymeric material. A method of cementing in a subterranean formation comprising providing a sealant composition comprising cement, water, and a rheology modifying additive wherein the rheology modifying additive comprises a gum and an anionic polymer, placing the composition in the subterranean formation, and allowing the cement composition to set therein.