Dissolvable Diverter Pack for Wellbore Perforation Sealing
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Solution Overview
Problem
Existing methods for controlling fluid flow in wellbores, such as using diverter balls, often fail to seat properly in casing perforations, necessitating alternative reliable methods for plugging openings in subterranean wells.
Innovation Solution
A diverter pack comprising a package portion and a wing portion, formed from dissolvable polyvinyl alcohol (PVA) films and potentially including a gel or additional components like polylactic acid, which is designed to be conveyed by fluid flow and seal openings in the wellbore, ensuring effective plugging of perforations, leaks, or corrosion holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diverter balls are used to plug perforations, then fluid flow control is achieved, but the diverter balls fail to seat properly in casing perforations
Solution Approach 1:
The patent employs a dissolvable pack made of water-soluble material that is deployed once and then discarded. The pack contains a diverter ball and dissolvable material that allows the ball to be propelled into the perforation. After serving its purpose of diverting flow, the pack dissolves and is removed by production fluids, eliminating the need for retrieval operations.
Solution Approach 2:
The patent changes the physical and chemical parameters of the pack material to be water-soluble and dissolvable. The pack is designed to maintain structural integrity during deployment and seating, then dissolve completely after performing the flow diversion function. This parameter change enables reliable seating while allowing easy removal through dissolution.
2Reliability
If conventional diverter balls are used, then flow diversion is attempted, but they do not reliably seal openings in perforations
Solution Approach 1:
The dissolvable pack is designed as a single-use device that is deployed, performs its sealing function, and then dissolves. This eliminates the need for complex retrieval operations and ensures that the pack is replaced with fresh material for each operation, maintaining high sealing reliability.
Solution Approach 2:
The pack comprises a composite structure including a diverter ball, dissolvable material, and optionally a gel. The dissolvable material and gel work together to propel the ball into the perforation and maintain sealing pressure. The gel may be water-soluble or non-water-soluble, providing additional sealing mechanism that enhances overall sealing reliability.
3Duration of action of moving object
If dissolvable materials are used in the diverter pack, then temporary functionality is achieved, but the materials must be degraded after use
Solution Approach 1:
The dissolvable pack is designed to serve its purpose and then be discarded. The water-soluble material is selected to dissolve under production conditions, automatically removing the pack from the wellbore without requiring intervention. This disposable approach simplifies the degradation process compared to retrieving and removing conventional diverter balls.
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 diverter pack effectively controls fluid flow by sealing openings in the wellbore, with the dissolvable materials ensuring temporary functionality until degradation, suitable for applications like hydraulic fracturing and addressing issues with conventional diverter balls.
Implementation Method 1
the first and second films comprises a first dissolvable material. According to some embodiments, the first dissolvable material is a first polyvinyl alcohol (PVA) compound
Data Source
AI summary
Methods and systems for diverting the flow of fluids within a wellbore are disclosed. The methods and systems use a flow conveyed diverter pack, which includes a package portion and a wing portion. The package portion may contain a ball (a.k.a. a diverter ball) and may contain additional components. The diverter pack may be formed by sandwiching a diverter ball between films of a flexible material, for example, films of a dissolvable polymer. The diverter pack may be deployed in a wellbore, whereby the pack is conveyed by fluid flow to an opening to be sealed. The diverter pack seats upon the opening, thereby diverting flow from the opening.