Viscoelastic Surfactant Fluids with Nanoparticle Composites for Leak-Off Control

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Solution Overview

Problem

Viscoelastic surfactant-based fluids used in fracturing and gravel-packing treatments suffer from high fluid leak-off due to lack of filter-cake formation, resulting in lower efficiency compared to crosslinked polymer fluids, necessitating improved fluid loss control without compromising other desirable properties.

Innovation Solution

A treatment fluid comprising an aqueous base fluid, a viscoelastic surfactant gelling agent, and a combination of two or more types of nanoparticles such as alkaline earth metal oxides and transition metal oxides, with a selected weight ratio, which synergistically enhances fluid efficiency by reinforcing the gel structure and reducing leak-off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If VES based fluids are used to maintain low formation damage characteristics, then formation damage is reduced, but fluid leak-off increases and fluid efficiency decreases

Engineering Contradiction:

Improveformation damageVSAvoidfluid leak-off

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent combines VES gelling agents with nanoparticles (such as silica, alumina, titania, zirconia, magnesia, or their core-shell composites) to create a composite fluid system. This composite approach allows the fluid to simultaneously maintain low formation damage characteristics while improving fluid loss control, as the nanoparticles provide filter-cake formation capabilities that the VES alone cannot provide.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the rheological and filtration parameters of VES fluids by adding nanoparticles with specific surface areas, pore sizes, and surface chemistries. These parameter changes enable the fluid to develop adequate filter-cake properties without compromising the low formation damage benefits of VES systems.

Inventive Principle:

Principle #35Parameter changes

2Loss of substance

If crosslinked polymer fluids are used to achieve low fluid leak-off, then fluid efficiency is improved, but formation damage increases

Engineering Contradiction:

Improvefluid leak-offVSAvoidformation damage

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite system that combines the benefits of crosslinked polymer fluids (low fluid leak-off) with the advantages of VES fluids (low formation damage). By incorporating nanoparticles into VES-based systems, the fluid achieves improved fluid loss control comparable to crosslinked polymers while avoiding their formation damage issues.

Inventive Principle:

Principle #40Composite materials

3Loss of substance

If nanoparticles are added to improve fluid efficiency, then fluid leak-off is reduced, but fluid composition complexity increases

Engineering Contradiction:

Improvefluid leak-offVSAvoidfluid composition

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent optimizes nanoparticle parameters including particle size (1-100 nm), surface area, pore size, and surface chemistry to achieve effective fluid loss control at low concentrations. This parameter optimization minimizes the impact on fluid composition complexity while maximizing fluid efficiency improvement.

Inventive Principle:

Principle #35Parameter changes

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 combination of nanoparticles improves fluid efficiency to levels comparable to polymer-based fluids while maintaining viscosity stability and avoiding formation damage, even at high temperatures and in high salinity brines, without impairing other fluid properties.

Implementation Method 1

a viscoelastic surfactant gelling agent, two or more types of the following nanoparticles... wherein the weight ratio of the two or more types of the nanoparticles is selected such that the treatment fluid has an improved fluid efficiency

Methodology Applied

Scientific EffectGel structure reinforcement: Gel

Implementation Method 2

viscoelastic surfactant (VES) based fluids have been widely used... because the fluids exhibit excellent rheological properties

Methodology Applied

Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 3

unlike crosslinked polymer fluids, VES fluids do not form filter-cake on formation face during fracturing and frac-pack treatments, thus VES fluids can exhibit very high fluid leak-off... The combination of nanoparticles improves fluid efficiency to levels comparable to polymer-based fluids

Methodology Applied

Scientific EffectNanoparticle filtration: Filter (physical)

Data Source

PatentUS10227522B2Fluid efficiency for viscoelastic surfactant based fluids with nanoparticles

Publication Date: 2019.03.12 BAKER HUGHES CO

AI summary

A method of treating a subterranean formation penetrated by a well comprises combining an aqueous base fluid, a viscoelastic surfactant gelling agent, two or more types of the following nanoparticles: an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; or a transition metal hydroxide to form a treatment fluid, and pumping the treatment fluid into the well, wherein the weight ratio of the two or more types of the nanoparticles is selected such that the treatment fluid has an improved fluid efficiency as compared to an otherwise identical reference fluid except for comprising only one type of the nanoparticles selected from an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; and a transition metal hydroxide.