Delayed Crosslinking Fracturing Fluid for Proppant Transport
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fracturing techniques are inadequate for treating low permeability formations like shale and tight gas reservoirs, as they fail to create adequate fracture networks and transport proppants effectively, leading to inefficient oil and gas recovery.
Innovation Solution
A non-aqueous slurry comprising a non-aqueous liquid immiscible in water, an oil-wetting surface active material, and a crosslinking agent, along with a water-soluble gellant, is used to create a fracturing fluid with enhanced viscoelasticity, delaying crosslinking and reducing friction pressure, which enables the creation of complex fracture networks and efficient proppant transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional high viscosity fracturing fluids are used, then proppant transport capability is improved, but friction pressure increases and operational costs increase
Solution Approach 1:
The patent changes the chemical parameters of the fracturing fluid by introducing crosslinking agents that modify the polymer structure. This transforms the fluid from conventional high viscosity to viscoelastic properties, achieving both low friction pressure during pumping and high proppant transport capability in the fracture.
Solution Approach 2:
The patent creates a composite fracturing fluid system combining polymers with crosslinking agents. This composite structure provides viscoelasticity, enabling the fluid to exhibit both low resistance during injection and high proppant carrying capacity in the fractured formation.
2Use of energy by moving object
If slickwater fracturing fluid is used, then friction pressure is reduced, but proppant transport capability deteriorates
Solution Approach 1:
The patent transforms the fluid parameters from simple low viscosity (slickwater) to viscoelastic properties through polymer addition and crosslinking. This parameter change enables the fluid to maintain low friction pressure while gaining enhanced proppant transport capability through elastic recoil mechanisms.
3Reliability
If conventional crosslinked fracturing fluids are used, then proppant transport is improved, but crosslinking time is insufficiently controlled leading to premature gelation
Solution Approach 1:
The patent applies preliminary action by adding the crosslinking agent to the polymer solution in advance, allowing controlled crosslinking to occur during pumping. This preliminary crosslinking ensures proper timing, preventing premature gelation while maintaining proppant transport capability throughout the treatment process.
4Reliability
If high viscosity fracturing fluid is used to create fracture width, then proppant carrying capacity is improved, but fluid injection rate is limited
Solution Approach 1:
The patent changes the rheological parameters of the fluid from conventional high viscosity to viscoelastic properties. This parameter change allows the fluid to be pumped at high rates with low friction pressure while maintaining sufficient viscosity and elasticity to carry proppant effectively into the fracture.
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 solution allows for the creation of complex fracture networks and efficient proppant transport in low permeability formations, reducing formation damage and increasing oil and gas recovery by minimizing hydraulic horsepower and operational costs.
Implementation Method 1
The oil-wetting surface active material decreases the rate of wetting of the crosslinking agent by water
Implementation Method 2
a crosslinking agent... along with a water-soluble gellant, is used to create a fracturing fluid with enhanced viscoelasticity, delaying crosslinking
Implementation Method 3
a non-aqueous liquid immiscible in water
Data Source
AI summary
A non-aqueous slurry contains a non-aqueous liquid immiscible in water (such as a hydrocarbon based oil) having dispersed therein a crosslinking agent (such as a borate crosslinking agent) and an oil-wetting surface active material. The non-aqueous slurry further contains an organophilic clay. The non-aqueous slurry, when used in an aqueous fracturing fluid, provides crosslinking delay between the crosslinking agent and a hydratable polymer, such as guar or guar derivatives. The aqueous fracturing fluid provides an enhanced fracture network after being pumped into a well.