Swellable Borate Sand Plugs for Horizontal Well Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In horizontal wellbores, existing sand plug systems are unreliable due to slumping and difficulty in setting and removing plugs, which complicates the isolation and treatment of multiple zones, leading to inefficient hydrocarbon production.
Innovation Solution
A swellable and degradable sand plug system using a slurry composition of a carrier fluid and a granular borate source material, which settles and expands with aqueous fluid exposure to fill the wellbore, providing reliable plugging and easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sand plugs are used in horizontal wellbores, then the wellbore can be plugged to isolate zones, but the sand plugs slump and fail to fully plug the diameter, leading to unreliable isolation
Solution Approach 1:
The sand plug composition is changed from traditional materials to a swellable material that increases its volume upon contact with formation water or injected aqueous fluid. This parameter change allows the plug to adapt to horizontal wellbore conditions by expanding to fill the wellbore diameter, ensuring reliable isolation without slumping
Solution Approach 2:
The sand plug transitions from a static, fixed-volume structure to a dynamic structure that can change its volume. The plug starts at a smaller volume for easy deployment and then expands dynamically when exposed to aqueous fluid, adapting to the wellbore geometry and providing stable, reliable plugging in horizontal sections
2Ease of repair
If clean-up or drill-out procedures are used to remove sand plugs from horizontal wellbores, then the plugs can be removed, but considerable time and expense are required
Solution Approach 1:
The sand plug material undergoes a phase transition from a solid, stable plug structure to a degraded, removable state through exposure to aqueous fluid. This chemical phase transition allows the plug to break down into soluble components that can be easily flushed from the wellbore, eliminating the need for time-consuming drill-out procedures
Solution Approach 2:
The sand plug is designed as a temporary, disposable element that serves its isolation function and then degrades naturally. Rather than designing for permanent installation requiring complex removal, the plug is intentionally made to be short-lived and easily removable through degradation, reducing both time and cost of wellbore intervention
3Device complexity
If a single stimulation operation is performed on multiple production zones, then the operation is simpler, but the treatment follows the path of least resistance and preferentially enters depleted zones with lower fracture gradients
Solution Approach 1:
The wellbore is segmented into multiple isolated zones using swellable sand plugs positioned between different production zones. This segmentation allows each zone to receive targeted stimulation treatment independently, preventing the treatment from following the path of least resistance into depleted zones and ensuring balanced hydrocarbon production from all zones
Solution Approach 2:
The swellable sand plugs serve as intermediary elements that physically separate and isolate different production zones. These intermediaries enable independent treatment of each zone by blocking fluid communication between zones, allowing optimization of stimulation for each zone's specific characteristics without interference from adjacent zones
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 system effectively isolates zones in horizontal wellbores, allowing for efficient treatment of multiple zones and easy removal of plugs, enhancing hydrocarbon production by ensuring consistent plugging and reducing cleanup time and expense.
Implementation Method 1
exposing the slurry composition to a sufficient amount of aqueous fluid. The aqueous fluid expands the slurry composition to the point that the expanded slurry composition substantially fills at least a portion of the horizontal wellbore
Implementation Method 2
the borate source material is at least partially dehydrated or anhydrous; allowing the slurry composition to settle in the horizontal wellbore and at least partially fill at least a portion of the horizontal wellbore in a direction vertical to the substantially horizontal wellbore; and exposing the slurry composition to a sufficient amount of aqueous fluid. The aqueous fluid expands the slurry composition
Data Source
AI summary
Disclosed herein are swellable and degradable sand plug systems used in wellbores and methods for using the systems in treating wellbores. The slurry composition includes a carrier fluid and a granular borate source material, where the borate source material is at least partially dehydrated or anhydrous. The carrier fluid may be non-aqueous fluid or, in some compositions, an aqueous fluid. The slurry composition is allowed to settle in a horizontal wellbore and at least partially fill at least a portion of the wellbore in a direction vertical to the wellbore, and is exposed to a sufficient amount of aqueous fluid to expand and substantially fill at least a portion of the wellbore, thereby plugging the wellbore. The slurry composition may be exposed to a sufficient amount of aqueous liquid to at least partially dissolve the expanded slurry composition, thereby at least partially removing the plug from the wellbore.