Delay Additive for Oil Gel Fracturing Fluids
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Solution Overview
Problem
Existing gel compositions for hydraulic fracturing in subterranean formations tend to gelate too quickly and become overly rigid, leading to instability and difficulty in pumping, especially in high-temperature applications.
Innovation Solution
Incorporating a delay additive, such as bis(2-hydroxyethyl)-cocoalkylamine oxide, into the gel composition to stabilize the fluid and delay cross-linking, preventing early gelation while maintaining fluid stability and predictability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If cross-linking agent and phosphate ester are introduced to gel liquid hydrocarbons, then gel strength and viscosity are improved, but gelation occurs too quickly causing fluid instability and pumping difficulty
Solution Approach 1:
An amine component is introduced as an intermediary substance that moderates the interaction between the cross-linking agent and phosphate ester. The amine delays the cross-linking reaction by forming intermediate complexes, allowing the gel to maintain fluid stability during pumping while still achieving the desired gel strength in the formation.
Solution Approach 2:
The gel composition is prepared with all components (hydrocarbon liquid, cross-linking agent, phosphate ester, and amine) mixed in advance, but the actual cross-linking gelation is delayed until the composition reaches the subterranean formation. This preliminary mixing allows the fluid to be pumped easily while ensuring gel strength develops at the right time and place.
2Loss of time
If cross-linking is accelerated to achieve faster gelation, then gelation time is reduced, but the gel becomes overly rigid causing pumping difficulties
Solution Approach 1:
The gel composition exhibits dynamic properties where the amine component continuously adjusts the cross-linking rate. During pumping, the amine suppresses rapid gelation maintaining fluidity, but upon reaching the formation, conditions change allowing controlled gelation to proceed at an optimal rate that balances timing and pumpability.
Solution Approach 2:
The amine component changes the chemical parameters of the system by modifying the reactivity between cross-linking agents and phosphate esters. This parameter modification delays the onset of gelation and controls the gelation rate, preventing the gel from becoming overly rigid while maintaining pumpability throughout the injection process.
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 addition of the delay additive effectively delays gelation and maintains fluid stability, allowing for predictable viscosity development and easier pumping, even in high-temperature conditions, thereby enhancing the usability of the gel composition in hydraulic fracturing.
Implementation Method 1
the delay additive can be added to the gel composition. The gel composition can be injected into the subterranean formation. The gel composition can be cross-linked.
Implementation Method 2
Gelled liquid hydrocarbons are often used as fracturing fluids for this hydraulic fracturing. It is known in the art to gel liquid hydrocarbons by the introduction of a phosphate ester and a crosslinking agent.
Data Source
AI summary
A gel composition for use in treating subterranean formations is provided. The gel composition is a non-aqueous based oil gel system that can include a hydrocarbon liquid capable of gelation, a phosphate ester, and a cross-linking agent. The gel composition can include the oil gel which results from adding a phosphate ester, a crosslinking agent and a delay additive to the hydrocarbon liquid.