CO2 Swellable Elastomers Divert Acid Flow in Subterranean Stimulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In subterranean formations, acid-based stimulation methods preferentially treat high permeability regions, leaving low permeability regions untreated and wasting acid in vugs or natural fractures, necessitating a fluid that can divert treatment to low permeability areas.
Innovation Solution
A treatment fluid comprising CO2-activated swellable elastomers is pumped into the borehole, which swells upon contact with carbon dioxide, partially blocking high permeability regions and diverting treatment to low permeability areas, using materials like chlorofluorocarbons, tetrafluoroethylene-propylene copolymers, or isobutene-isoprene rubbers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acid-based stimulation is used to treat subterranean formations, then high permeability regions are effectively treated, but low permeability regions remain untreated and acid is wasted in vugs or natural fractures
Solution Approach 1:
The treatment fluid incorporates swellable elastomeric particles that dynamically change their properties in response to CO2 exposure. The particles remain small and non-obstructive during injection, then swell upon contact with CO2 to plug high permeability regions, thereby dynamically adapting the treatment approach to achieve both high and low permeability region treatment while preventing acid waste
Solution Approach 2:
The elastomeric particles undergo a parameter change in their volume when exposed to CO2. This swelling transformation allows the particles to transition from a state that permits easy fluid flow during injection to a state that effectively plugs high permeability regions, thereby changing the treatment dynamics to improve acid utilization and prevent waste
2Productivity
If acid flows into high permeability regions, then those regions receive treatment, but low permeability regions are left untreated
Solution Approach 1:
The treatment fluid is pre-conditioned with swellable elastomeric particles before injection. These particles are designed to swell upon contact with CO2, which is present in the formation. The preliminary preparation of the fluid with these responsive particles enables automatic diversion of acid flow from high to low permeability regions as the particles swell, ensuring uniform treatment across different permeability zones
Solution Approach 2:
The treatment system utilizes the naturally present CO2 in the formation to activate the swelling of elastomeric particles. This self-service mechanism allows the treatment fluid to automatically adapt and divert flow to untreated low permeability regions without requiring external control, thereby achieving both high productivity and treatment uniformity
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 CO2-activated swellable elastomers effectively seal off high permeability regions, ensuring more targeted treatment of low permeability areas, enhancing hydrocarbon production by optimizing fluid flowpaths in subterranean formations.
Implementation Method 1
a material that swells when contacts with carbon dioxide
Data Source
AI summary
The current application discloses compositions and methods for treating a subterranean formation. CO2 swellable elastomers can be used in a treatment fluid to at least partially block a high permeability region, therefore improving the performance of an operation such as matrix stimulation, acidizing, and acid fracturing.