Proppant Suspension via Low-Density Particulates in Fracturing Fluids

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Solution Overview

Problem

Proppant aggregates in hydraulic fracturing operations tend to settle and aggregate, reducing fracture conductivity due to their higher density, which is exacerbated by the use of reduced proppant volumes, leading to potential closure of fractures and decreased production efficiency.

Innovation Solution

A combination of a carrier fluid with a specific density range (0.75-1.25 g/cm3) and proppant aggregates with a higher density (>1.1 g/cm3) is used, along with low-density particulates (<0.95 g/cm3) to create a propping fluid that slows the settling of proppant aggregates within the fracture by mutual interference, promoting a more random distribution and increased suspension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If reduced volumes of proppants are used to create high porosity fracture, then fracture conductivity is improved, but proppant settling occurs leading to fracture closure and reduced conductivity

Engineering Contradiction:
Improvefracture conductivityVSAvoidfracture stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A viscosity-enhancing polymer is introduced as an intermediary substance in the carrier fluid to counteract the settling of proppant aggregates. The polymer increases fluid viscosity, providing greater buoyant support to keep the reduced proppant volumes suspended throughout the fracture, thereby maintaining both high porosity and fracture stability without requiring excessive proppant quantities

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If high pump rate or increased fluid viscosity is used to counteract proppant settling, then proppant suspension is improved, but effectiveness is lost once fluid is placed into fracture and before fracture pressure is released

Engineering Contradiction:
Improveproppant suspensionVSAvoidsuspension effectiveness duration
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of moving object

Solution Approach 1:

The polymer concentration and molecular weight are specifically selected to provide optimal viscosity enhancement that maintains proppant suspension throughout the entire fracture placement and pressure release period. The polymer's viscosifying effect persists at reservoir conditions, ensuring prolonged suspension effectiveness without relying on high pump rates that lose effectiveness over time

Inventive Principle:
Principle #35Parameter changes

3Productivity

If proppant aggregates are used instead of traditional proppant, then proppant placement efficiency is improved, but settling is exacerbated due to larger size and higher weight

Engineering Contradiction:
Improveproppant placement efficiencyVSAvoidproppant settling
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The viscosity-enhancing polymer creates a more resistant carrier fluid that counteracts the increased gravitational force on larger proppant aggregates. The enhanced viscosity provides greater drag force and buoyant support, effectively balancing the heavier weight of aggregates and preventing their premature settling, thus maintaining placement efficiency while mitigating the harmful settling effect

Inventive Principle:
Principle #8Anti-weight (Counterweight)

4Stability of the object's composition

If high concentration of gelling agents is used to maintain proppant suspension, then proppant settling is reduced, but formation damage increases and production efficiency decreases

Engineering Contradiction:
Improveproppant suspensionVSAvoidformation damage
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The polymer concentration is optimized to provide sufficient viscosity enhancement for proppant suspension while remaining below thresholds that cause formation damage. The polymer's molecular characteristics are selected to achieve effective suspension at lower concentrations compared to traditional gelling agents, thereby maintaining proppant stability without compromising formation permeability or production efficiency

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

This approach enhances the suspension of proppant aggregates, maintaining fracture conductivity and reducing the need for high gelling agents, thereby improving production efficiency and reducing formation damage.

Implementation Method 1

providing low-density particulates having a density lower than that of the carrier fluid... wherein the low-density particulates slow the settling of the proppant aggregates within the fracture

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

providing a carrier fluid having a density; providing a proppant aggregates having a density higher than that of the carrier fluid; providing low-density particulates having a density lower than that of the carrier fluid

Methodology Applied
Scientific EffectDensity difference: Density Gradient

Data Source

PatentUS8960284B2Methods of hindering the settling of proppant aggregates
Publication Date: 2015.02.24 HALLIBURTON ENERGY SERVICES INC

AI summary

Providing a carrier fluid having a density; providing a proppant aggregates having a density higher than that of the carrier fluid; and, providing low-density particulates having a density lower than that of the carrier fluid. Then the carrier fluid, proppant aggregates, and low-density particulates are combined to create a propping fluid. The propping fluid then is placed into a fracture within a subterranean formation wherein the low-density particulates slow the settling of the proppant aggregates within the fracture.