Oxidative Internal Breaker System for Delayed VES Fluid Breaking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for breaking viscoelastic surfactant fluids in oilfield treatments are inefficient due to limited interaction between pre-flush or post-flush fluids and the viscoelastic surfactant fluids, especially in formation pores, requiring high volumes and relying on slow diffusion, and lack effective mechanisms for delayed breaking at lower temperatures.
Innovation Solution
An aqueous fluid composition containing a non-polymeric viscosifier and an oxidizing agent, such as bromate salts, combined with specific breaking activators like sodium thiosulfate or glutaraldehyde, which synergistically reduce viscosity and allow for pre-selectable breaking times, even at lower temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If pre-flush or post-flush fluids are used to break viscoelastic surfactant fluids in formation pores, then the fluid can be diluted or contacted with a breaker, but the interaction is limited due to small interface between fluids, requiring high volumes and relying on slow diffusion
Solution Approach 1:
The invention combines the breaker and activating agent into a single integrated composition that is injected with the viscoelastic surfactant fluid itself. This merging eliminates the need for separate pre-flush or post-flush fluids, allowing the breaker to act directly on the VES fluid through intimate mixing and chemical reaction, thereby achieving efficient breaking with minimal fluid volumes.
Solution Approach 2:
The invention introduces an activating agent as an intermediary substance that triggers the breakdown of the viscoelastic surfactant. This activating agent serves as a mediator between the breaker and the VES fluid, enabling controlled degradation through chemical activation rather than relying on slow diffusion-based dilution processes.
2Temperature
If conventional breakers are used in viscoelastic surfactant fluids, then they can degrade surfactants or destroy micelles, but they cannot achieve delayed breaking at lower temperatures
Solution Approach 1:
The breaker is pre-injected with the viscoelastic surfactant fluid and remains dormant during the treatment process. The activating agent is then introduced separately to trigger the breaking action at the desired time and temperature conditions. This preliminary positioning of the breaker allows for delayed activation without requiring high temperatures.
Solution Approach 2:
The invention changes the activation parameters by using an activating agent that can trigger breaker functionality at lower temperatures than conventional systems. This parameter change enables controlled delayed breaking to occur at temperatures that do not compromise the integrity of the formation or require excessive thermal energy input.
3Productivity
If oxidizing agents are used to break viscoelastic surfactant fluids, then they can degrade the surfactant molecules, but they require high temperatures to activate the breaking mechanism
Solution Approach 1:
The activating agent acts as an intermediary that enables the oxidizing breaker to function at lower temperatures. It facilitates the chemical reaction between the breaker and surfactant molecules without requiring high thermal energy, thereby maintaining breaking effectiveness while reducing temperature requirements.
Solution Approach 2:
The invention uses a specifically selected oxidizing breaker that, when combined with the activating agent, provides accelerated oxidation of the surfactant molecules at lower temperatures. This strong oxidant system overcomes the typical temperature barrier associated with oxidative breaking mechanisms.
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 composition effectively breaks viscoelastic surfactant fluids in subterranean formations by reducing viscosity, allowing for controlled breaking times and temperatures, enhancing the efficiency of oilfield treatments like hydraulic fracturing and gravel packing.
Implementation Method 1
an oxidizing agent selected, for example, from peroxysulfuric acid, a peroxymonosulfuric acid salt, persulfates, peroxides, hydroperoxides, azo compounds, peracids, perborates, peresters, bromates, iodates, periodates, permanganates, chlorites, andhyperchlorites
Implementation Method 2
The composition may optionally include a free radical propagating agent, for example ferrous ions, metabisulfites, reducing sugars, and reducing di-, tri-, oligo- and poly-saccharides
Implementation Method 3
The composition may optionally include an oxygen scavenger, for example sulfites, furanones, hydroxyl amines, trivalent phosphorous compounds, phenolic antioxidants, thiosulfates, metabisulfites, hydrazines, carbohydrazides, hydroquinones, and erythorbates
Data Source
AI summary
Compositions and methods are given for delayed breaking of viscoelastic surfactant gels inside formation pores, particularly for use in hydraulic fracturing. Breaking inside formation pores is accomplished without mechanical intervention or use of a second fluid. Bromate oxidizing agents are used along with selected breaking activators for the bromate breaking compounds. Useful bromate breaking activators include acid-generating breaking activators, oxidizing sulfur containing breaking activators, and reducing agent breaking activators.