Amphoteric Surfactant Treatment for Saltwater Disposal Well Injectivity
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Solution Overview
Problem
Existing methods for treating produced water in saltwater disposal wells fail to effectively remove oily suspended solids without interfering with chelating agents and scaling inhibitors, leading to reduced injectivity and increased maintenance costs.
Innovation Solution
The use of alkyl amphocarboxylates, such as disodium cocoamphodiacetate, in combination with organic chelating agents and scale inhibitors, to treat produced water, enhancing its injectivity without disrupting the action of these agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If commonly used surfactants are introduced to destabilize and disperse the oily layer, then the oily suspended solids are removed, but the chelating agents and scaling inhibitors are interfered with and their effectiveness is counteracted
Solution Approach 1:
The patent changes the chemical parameters of the surfactant by selecting amphoteric surfactants with specific molecular structures (containing both cationic and anionic groups) that have different chemical properties from commonly used surfactants. This parameter change allows the surfactant to disperse oily solids without interfering with chelating agents and scaling inhibitors, thus resolving the contradiction between removing oily suspended solids and maintaining the effectiveness of other treatment chemicals
Solution Approach 2:
The patent uses composite chemical structures in amphoteric surfactants that combine both cationic and anionic functional groups within the same molecule. This composite structure enables the surfactant to interact with oily suspended solids through multiple mechanisms while being compatible with chelating agents and scaling inhibitors, thereby achieving both oil removal and chemical compatibility
2Object-generated harmful factors
If organic chelating agents are introduced to prevent formation and dissolve solid particulates, then suspended solids are removed, but they cannot penetrate through the oily layer around suspended solids
Solution Approach 1:
The patent introduces amphoteric surfactants as intermediary substances that first penetrate and destabilize the oily layer surrounding suspended solids. This creates access for organic chelating agents to reach and bind with the suspended solids. The surfactant acts as a mediator that enables the chelating agents to overcome the barrier posed by the oily layer, thus resolving the contradiction between solid removal effectiveness and penetration capability
3Object-affected harmful factors
If produced water is injected back into the ground, then environmental disposal is achieved, but pressure buildup occurs and injectivity is reduced due to fouling
Solution Approach 1:
The patent extracts and removes the problematic components (oily suspended solids and fouling materials) from the produced water through chemical treatment with amphoteric surfactants and chelating agents. By removing these foulants before injection, the treated water has improved injectivity and causes less pressure buildup in the disposal well, thus resolving the contradiction between achieving environmental disposal and minimizing pressure buildup
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
Alkyl amphocarboxylates improve the injectivity of produced water by effectively dispersing inorganic solids like iron oxide and iron sulfide, while maintaining the effectiveness of chelating agents and scale inhibitors, thereby reducing pressure buildup and maintenance costs.
Implementation Method 1
Alkyl amphocarboxylates improve the injectivity of produced water by effectively dispersing inorganic solids like iron oxide and iron sulfide
Implementation Method 2
Some attempts have been made to address this problem by introducing surfactants that can destabilize and disperse the oily layer
Implementation Method 3
Existing methods for treating produced water include introducing organic chelating agents, which can prevent formation of solid particulates such as iron oxide and iron sulfide, and dissolve or break down any such particulates that are already present
Data Source
AI summary
A method for treating water includes adding an alkyl amphocarboxylate and an organic chelating agent to the water. Furthermore, a composition includes disodium cocoamphodiacetate in an amount in the range of from 0.1 to 10.0 wt %; an organic chelating agent in an amount in the range of from 1.0 to 50.0 wt %; and water.