Micellar Dispersion for Wellbore Damage Removal
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Solution Overview
Problem
Current well treatment methods require multiple stages or incorporate hazardous acids to address formation damage in oil and gas wells, limiting their effectiveness in removing hydrocarbon, emulsion, and water blockages, especially in long openhole situations and at higher temperatures.
Innovation Solution
A micellar dispersion comprising water, at least 1% w/v of organic acid precursors that produce formic acid, acetic acid, or glycolic acid upon hydrolysis, along with surfactants and optional salts or co-surfactants, is introduced into the wellbore, allowing for in-situ acid production to dissolve acid-soluble materials within a single stage treatment, providing controlled acid delivery and improved zonal coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional acidizing formulations with low concentrations of surfactants are used, then acid-soluble materials can be dissolved, but hydrocarbon and emulsion blockages remain ineffective and may coat the acid-soluble materials, limiting treatment effectiveness
Solution Approach 1:
The patent uses a composite micellar dispersion system containing both ionic and nonionic surfactants combined with acid. This composite formulation allows the solution to simultaneously interact with and remove both hydrocarbon/emulsion blockages (via micellar action) and acid-soluble materials (via acid dissolution), resolving the contradiction between handling multiple damage types and maintaining treatment reliability.
Solution Approach 2:
The micellar dispersion with dual surfactant system performs multiple functions in a single treatment: it solubilizes hydrocarbons, removes emulsions, and dissolves acid-soluble materials. This multi-functional approach eliminates the need for separate treatments for different damage types, thereby improving both versatility and reliability simultaneously.
2Reliability
If multiple stage treatments are used to address different types of formation damage, then comprehensive damage removal can be achieved, but treatment complexity and time increase
Solution Approach 1:
The patent merges multiple treatment functions into a single micellar dispersion formulation that contains both ionic and nonionic surfactants along with acid. This combined approach allows simultaneous removal of hydrocarbon blockages, emulsion damage, and acid-soluble materials in one treatment stage, eliminating the need for multiple sequential treatments and thereby reducing process complexity while maintaining comprehensive damage removal.
Solution Approach 2:
The single-stage micellar dispersion treatment performs multiple functions that would traditionally require separate treatments: hydrocarbon solubilization, emulsion removal, and acid-soluble material dissolution. This universal treatment approach achieves comprehensive damage removal while simplifying the overall treatment process.
3Reliability
If acids are introduced to dissolve acid-soluble materials, then carbonate deposits can be removed, but premature leak-off and corrosion risks increase
Solution Approach 1:
The micellar dispersion acts as an intermediary system that delivers acid to the formation in a controlled manner. The micellar structure allows the acid to be transported and released gradually at the treatment site, reducing premature leak-off. The surfactants also provide corrosion inhibition, thereby maintaining reliable acid-soluble material dissolution while minimizing harmful effects.
Solution Approach 2:
The patent changes the physical and chemical parameters of the acid delivery system by incorporating it into a micellar dispersion with dual surfactants. This modification alters the acid's release profile and interaction characteristics, enabling controlled acid delivery that reduces premature leak-off and corrosion risk while maintaining effective dissolution of acid-soluble materials.
4Reliability
If high concentrations of surfactants are used to solubilize hydrocarbons, then emulsion and water blockages can be removed, but treatment cost and environmental impact increase
Solution Approach 1:
The patent employs a composite surfactant system with both ionic and nonionic components that work synergistically. This composite approach achieves effective hydrocarbon solubilization and emulsion removal at lower overall surfactant concentrations compared to using single surfactant types at high concentrations, thereby reducing environmental impact while maintaining treatment reliability.
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 effectively solubilizes hydrocarbons and emulsions while dissolving acid-soluble materials, enhancing production or injection rates and increasing permeability, while being environmentally friendly and reducing the risk of premature leak-off and corrosion.
Implementation Method 1
The use of micellar dispersions, also known as 'transparent emulsions', 'micellar solutions' or 'microemulsions' for well treatments has been previously taught.
Implementation Method 2
at least 1% w/v of organic acid precursors, wherein hydrolysis of the organic acid precursor produces formic acid, acetic acid or glycolic acid
Implementation Method 3
Conventional acidizing formulations typically include low concentrations of suitable surfactants to water wet the surfaces of acid-soluble materials to facilitate their dissolution.
Implementation Method 4
The effective removal of damage, especially near wellbore damage such as filter cake, can significantly increase the production rate of hydrocarbon or water producing wells penetrating underground formations.
Data Source
AI summary
A process is disclosed for treating an underground formation, which process comprises: (a) introducing into the underground formation a micellar dispersion comprising water, one or more organic acid precursors, one or more surfactants and, optionally, one or more salts, co-surfactants and/or organic liquids that are not organic acid precursors; and (b) allowing (i) the micellar dispersion to solubilise hydrocarbons, emulsions or water blocks present in the underground formation, and (ii) at least a portion of the organic acid precursor to hydrolyse in-situ to produce sufficient organic acid to substantively dissolve acid soluble material present in or adjacent to filter cakes or other damage in the underground formation.