Amine Oxide Flowback Aids for Fracturing Fluids
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic fracturing fluids often leave behind an irreducible fraction that impedes hydrocarbon flow due to capillary pressure and water blocks, necessitating the use of flowback aids that balance desirable and undesirable properties, and determining the best aid for a specific reservoir is challenging.
Innovation Solution
An aqueous fracturing fluid containing an amine oxide of the formula (CH3)NO(R1)(R2), where R1 and R2 are independently selected from linear or branched alkyl groups having from 8 to 16 carbon atoms, is introduced into the subterranean formation to fracture and facilitate flowback, with a preferred concentration of 0.2 to 2.0 percent by weight, often combined with a non-ionic co-surfactant like alcohol ethoxylate to achieve a contact angle greater than 80 degrees and surface tension less than 24 mN/m.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If known flowback aids are used to reduce capillary pressure and improve flowback, then flowback efficiency is improved, but tradeoffs of undesirable properties occur
Solution Approach 1:
The patent changes the chemical parameters of the flowback aid by specifying amine oxides with particular alkyl group configurations (8-16 carbon atoms). This parameter specification optimizes the balance between flowback efficiency and undesirable properties, achieving contact angles greater than 80 degrees while maintaining acceptable surface tension characteristics.
Solution Approach 2:
The patent employs composite surfactant systems combining amine oxides with other compatible surfactants. This composite approach allows optimization of multiple properties simultaneously - the amine oxide provides high contact angle for efficient flowback while complementary surfactants mitigate undesirable effects such as excessive surface tension reduction or environmental concerns.
2Productivity
If water saturation in pores is reduced to increase hydrocarbon flow, then production is increased, but fracturing fluid must be effectively flowedback
Solution Approach 1:
The patent applies flowback aids to the fracturing fluid before injection into the formation. This preliminary action ensures that when the fluid enters the formation pores, it is pre-equipped with surfactant properties that will facilitate subsequent flowback, preventing fluid entrapment and ensuring efficient recovery before hydrocarbon production begins.
Solution Approach 2:
The amine oxide surfactant acts as an intermediary substance between the aqueous fracturing fluid and the hydrocarbon-bearing formation. It mediates the interaction by reducing interfacial tension and modifying wettability, allowing the fracturing fluid to flow back efficiently while leaving minimal residual saturation that would impede hydrocarbon flow.
3Ease of operation
If contact angle is increased to greater than 80 degrees to improve flowback, then aqueous fluid flowback is enhanced, but surface tension must be controlled
Solution Approach 1:
The patent specifies precise parameter ranges for the amine oxide components, including alkyl group carbon atom counts (8-16) and concentration ranges (0.2-2.0% by weight). These parameter changes optimize the relationship between contact angle and surface tension, achieving contact angles greater than 80 degrees for improved flowback while maintaining surface tension within acceptable ranges for effective fracturing fluid performance.
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 amine oxide and co-surfactant combination effectively reduces water saturation in the subterranean formation, enhancing hydrocarbon flowback and production by ensuring a high contact angle and low surface tension, thereby improving the efficiency of fracturing fluid flowback and hydrocarbon extraction.
Implementation Method 1
A flowback aid may be included in the fracturing fluid to reduce capillary pressure and water blocks, thereby improving the kinetics of the flowback
Implementation Method 2
a scientific measure of the ability of a flowback aid to change the wettability of the near wellbore formation can be obtained by accurately measuring the contact angle formed by the flowback aid within a capillary tube
Implementation Method 3
achieve a contact angle greater than 80 degrees and surface tension less than 24 mN/m
Implementation Method 4
Reducing the water saturation in the pores of the targeted subterranean petroliferous formation is desirable for increased production of oil or gas because the volume of the flow channel for oil or gas through the pores in the rock will be occupied, in part, by the immiscible water phase
Data Source
AI summary
An aqueous fracturing fluid comprises an environmentally friendly flowback aid. The flowback aid includes an amine oxide having the formula (CH3)NO(R1)(R2), where R1 and R2 are independently selected from linear or branched alkyl groups having from 8 to 16 carbon atoms. Optionally, the fracturing fluid may further comprise an alcohol ethoxylate of the formula R3—(OC2H4)x—OH, wherein R3 is a linear or branched alkyl group having from 6 to 18 carbon atoms, and wherein x ranges from 3 to 25. One example of an amine oxide is didecylmethyl amine oxide, and one example of an alcohol ethoxylate is ethoxylated isodecylalcohol (also known as ethoxylated isodecanol). The fracturing fluid is introduced through a well bore into the subterranean formation and pressurized to fracture the subterranean formation. The fracturing fluid is then allowed to flow back into the well bore from the subterranean formation.