Delayed Polymer Breaker for Subterranean Fluids
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Solution Overview
Problem
Current well completion procedures using polymer breakers face challenges in achieving strongly delayed, controllable breaks of biopolymer viscosified fluids and filter cakes at temperatures below 150° F, as reducing breaker concentrations can result in incomplete breaks and damage to the permeability of the producing zone.
Innovation Solution
A water-based treating fluid composition comprising a mixture of a hydrogen peroxide source, a ferrous ion source, and a chelating agent is used to create a strongly delayed polymer breaker system, which includes a weak oxidizer that is slowly catalyzed to a strong oxidizer, allowing for controlled degradation of biopolymers like xanthan gum, preventing ferric ion precipitation through citrate addition, and maintaining flexibility in break time control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the concentration of polymer breaker is reduced to achieve longer break time, then the break time is extended, but the break becomes incomplete and permeability of the producing zone is damaged
Solution Approach 1:
The patent introduces temperature as a controllable parameter to regulate the activation of the polymer breaker. By using a thermally-activated breaker system, the break time can be precisely controlled without reducing the breaker concentration, thus maintaining both extended break time and complete break effectiveness while protecting zone permeability.
Solution Approach 2:
The polymer breaker is introduced into the treatment fluid in advance but remains dormant until thermal activation occurs in the subterranean formation. This preliminary incorporation allows the breaker to be present at the right location and concentration, activating only when needed to achieve complete break without damaging permeability.
2Loss of time
If a strongly delayed polymer breaker is used to achieve break delay of more than 3 hours, then the break time is strongly delayed, but it becomes difficult to obtain controllable break times at temperatures below 150° F
Solution Approach 1:
The patent employs a thermally-activated polymer breaker system where the activation temperature can be selected based on the desired break time and formation temperature. This allows the same breaker system to provide controllable break times across a wide temperature range (80-150° F), achieving strongly delayed breaks (>3 hours) while maintaining adaptability to different temperature conditions.
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 solution provides a controllable, strongly delayed break of biopolymer viscosified fluids and filter cakes across a range of temperatures from 80 to 150° F, ensuring effective removal of fluids and filter cakes without compromising the permeability of the subterranean zone.
Implementation Method 1
a ferrous ion source which is slowly converted to a ferric ion source in the presence of a chelating agent
Implementation Method 2
which includes a weak oxidizer that is slowly catalyzed to a strong oxidizer
Implementation Method 3
a chelating agent that complexes with iron
Data Source
AI summary
Methods and compositions for breaking treatment fluids utilized in the stimulation of a subterranean formation.