Stable Chlorine Dioxide Precursor for Subterranean Biocide Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional biocides used in the petroleum industry are ineffective against dormant and spore-forming bacteria in hydrocarbon-bearing formations, and chlorine dioxide applications are limited due to premature oxidation of polymers and friction-control additives, leading to incomplete disinfection and equipment damage.
Innovation Solution
A stable chlorine dioxide precursor, such as sodium chlorate, is introduced into fracturing fluids that remains inactive until reaching a subterranean formation above 43°C, where it reacts to form chlorine dioxide, acting as a polymer oxidant, biocide, and reducing agent to address bacterial and sulfur compound issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chlorine dioxide is applied directly to well fluids for disinfection, then bacterial control is improved, but polymer degradation and depletion of friction-reducing components occur
Solution Approach 1:
The patent introduces a stable chlorine dioxide precursor that is injected into the well fluid beforehand but remains inactive during transport. The precursor only converts to active chlorine dioxide when it reaches the target formation zone, ensuring that polymer degradation is prevented during fluid injection while disinfection occurs in-situ at the formation
Solution Approach 2:
The patent uses a stable precursor compound as an intermediary form of chlorine dioxide. This precursor serves as a carrier that transports the disinfectant capability without exhibiting the harmful oxidative effects of active chlorine dioxide, thereby protecting polymers and friction-reducing additives during injection
2Reliability
If conventional biocides are used to control bacteria in fracturing fluids, then active bacteria are killed to some extent, but dormant and spore-forming bacteria survive and thrive
Solution Approach 1:
The patent employs chlorine dioxide, which fundamentally changes the disinfection mechanism compared to conventional biocides. Chlorine dioxide acts through oxidation that is effective against all bacterial states including dormant and spore-forming bacteria, rather than relying on mechanisms that only affect actively metabolizing bacteria
3Strength
If high dosage chlorine dioxide is applied to prevent polymer degradation, then polymer protection is improved, but the cost and potential harmful effects increase
Solution Approach 1:
The stable precursor acts as an intermediary that prevents premature polymer degradation during injection. Since the precursor does not exhibit oxidative activity until conversion in the formation zone, polymers are protected during transport without requiring high dosages of active chlorine dioxide, thereby reducing residual toxicity and economic costs
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 in-situ generation of chlorine dioxide effectively degrades polymers, reduces sulfur compounds, and kills bacteria, including dormant and spore forms, without depleting friction-reducing components in fracturing fluids, enhancing petroleum production and equipment integrity.
Implementation Method 1
introducing a chlorine dioxide precursor, such as sodium chlorate, into fracturing fluids that remains inactive until reaching a subterranean formation above 43°C, where it reacts to form chlorine dioxide
Implementation Method 2
acts as a polymer oxidant, biocide, and reducing agent to address bacterial and sulfur compound issues
Implementation Method 3
kills bacteria, including dormant and spore forms
Implementation Method 4
reduces sulfur compounds
Data Source
AI summary
According to one aspect of the invention, a method of converting an oxy halide salt into a halide dioxide in a reaction zone under certain conditions is provided. More specifically, the method includes generating chlorine dioxide from a stable composition comprising an oxy halide salt by introducing said composition to a reducing agent and minimum temperature within the reaction zone. According to another aspect of the invention, a composition for a stable chlorine dioxide precursor comprising an oxy halide salt is provided.