Amino Polyether Chelating Fluid for Scale Removal
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Solution Overview
Problem
Conventional methods for removing mineral scale deposits in wellbores are ineffective, particularly for resistant scales like barium sulfate, and often result in corrosive acid treatments or re-deposition of scales, while conventional chelating agents have low biodegradability and accumulate in the environment.
Innovation Solution
A method using a wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent or its precursor, combined with an aqueous base fluid, to effectively remove mineral scale deposits by forming stable complexes with metal ions, thereby preventing re-precipitation and offering biodegradability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional acid dissolution treatments are used to remove scale deposits, then calcium carbonate scales can be removed effectively, but the wellbore equipment and formation are damaged due to corrosive effects
Solution Approach 1:
The invention changes the chemical parameters of the treatment fluid by using amino polyether multicarboxylic acid chelating agents instead of conventional strong acids. This parameter change allows for effective scale removal through chelation while maintaining a pH range (2-12) that prevents corrosive damage to wellbore equipment and formation, thus resolving the contradiction between removal effectiveness and harmful corrosive effects
Solution Approach 2:
The amino polyether multicarboxylic acid chelating agent acts as an intermediary substance that facilitates scale removal without direct corrosive attack. The chelating agent forms stable soluble complexes with metal ions in the scale deposits, enabling removal through complexation rather than corrosive dissolution, thereby protecting equipment and formation while achieving scale removal
2Productivity
If conventional chelating agents are used to remove scale deposits, then scale removal is achieved, but environmental accumulation occurs due to low biodegradability
Solution Approach 1:
The invention employs biodegradable amino polyether multicarboxylic acid chelating agents that function as temporary, environmentally benign substances. These agents perform their scale removal function and then degrade naturally through biological processes, unlike conventional chelating agents that persist in the environment. This principle resolves the contradiction by providing effective scale removal with agents that do not accumulate environmentally
Solution Approach 2:
The biodegradability of the amino polyether multicarboxylic acid chelating agents involves oxidative degradation processes where microorganisms break down the chelating agent molecules. This accelerated natural degradation through biological oxidation ensures the agents do not accumulate in the environment, resolving the contradiction between effective scale removal and environmental persistence
3Productivity
If conventional acid dissolution treatments are used to remove scale deposits, then some scales are removed, but re-precipitation or re-deposition of scale occurs on surfaces
Solution Approach 1:
The amino polyether multicarboxylic acid chelating agent serves as an intermediary that forms stable soluble complexes with metal ions. These chelated complexes prevent re-precipitation by keeping metal ions in solution through stable complexation, thereby eliminating the re-deposition problem that occurs with conventional acid treatments where metal ions can re-precipitate as scale
Solution Approach 2:
The invention changes the chemical state of metal ions from free ions (prone to re-precipitation) to chelated complexes (stable in solution). This parameter change in the chemical form of dissolved metals, achieved through chelation, prevents re-precipitation and re-deposition on surfaces, resolving the contradiction between scale removal and scale stability
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 effectively removes mineral scale deposits without corrosive effects, reduces environmental impact, and prevents re-deposition, enhancing wellbore operations and production efficiency while minimizing environmental harm.
Implementation Method 1
a wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent and/or an amino polyether multicarboxylic acid chelating agent precursor... effectively remove mineral scale deposits by forming stable complexes with metal ions
Data Source
AI summary
A method of servicing a wellbore in a subterranean formation comprising preparing a wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent and/or an amino polyether multicarboxylic acid chelating agent precursor, and an aqueous base fluid, and contacting the wellbore servicing fluid with scale deposits on a surface in the wellbore and/or subterranean formation. A method of servicing a wellbore in a subterranean formation comprising preparing a wellbore servicing fluid comprising an amino polyether multicarboxylic chelating agent precursor and an aqueous base fluid, and contacting the wellbore servicing fluid with scale deposits on a surface in the wellbore and/or subterranean formation. A scale-removing wellbore servicing fluid comprising an amino polyether multicarboxylic acid chelating agent and/or an amino polyether multicarboxylic acid chelating agent precursor, and an aqueous base fluid.