Multilayered Ball Sealer for Irregular Perforation Sealing
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Solution Overview
Problem
Existing ball sealers fail to provide effective seals in wells with oval or burred perforation openings due to their spherical shape, leading to fluid flow and erosion issues, which limits their sealing capacity and longevity.
Innovation Solution
Multilayered ball sealers with a deformable layer, comprising an inner core, an intermediate deformable layer, and an outer layer that adapts to the shape of the perforation under pressure, using materials like elastomers and thermoplastic elastomers, and optionally a water-soluble or hydrolysable outer layer for controlled dislodging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional spherical ball sealers are used, then the device complexity is low and ease of manufacture is high, but the sealing effectiveness deteriorates due to inability to adapt to oval or burred perforation shapes
Solution Approach 1:
The ball sealer is divided into multiple functional layers: a rigid core layer for structural integrity and pressure resistance, and a deformable outer layer for adapting to perforation shapes. This segmentation allows each layer to perform its specific function optimally, resolving the contradiction between sealing effectiveness and structural simplicity.
Solution Approach 2:
The ball sealer uses composite material construction combining a rigid core material (such as plastic or rubber) with a deformable outer layer material. This composite structure enables the ball sealer to maintain structural strength while simultaneously adapting its outer surface to irregular perforation geometries, thereby improving sealing effectiveness without excessive complexity.
2Reliability
If ball sealers are made larger to improve sealing coverage, then the sealing capacity improves, but the ability to enter and seat in perforations deteriorates
Solution Approach 1:
The ball sealer incorporates a deformable outer layer that can dynamically change its shape and size in response to applied pressure. When the ball sealer enters the perforation, it maintains a compact spherical shape for easy entry. Once seated, the deformable layer expands and deforms under pressure to maximize sealing coverage, thus resolving the contradiction between entry ease and sealing capacity.
Solution Approach 2:
The ball sealer's outer layer changes its physical parameters (shape, volume, density) in response to pressure conditions. At low pressure during entry, the ball maintains its original compact parameters. Upon seating and under increased pressure, the parameters change to provide enhanced sealing contact, thereby achieving both easy entry and high sealing capacity.
3Duration of action of stationary object
If ball sealers remain permanently lodged in perforations, then the sealing durability improves, but the ability to dislodge post-treatment deteriorates
Solution Approach 1:
The ball sealer is designed as a temporary sealing device with a controlled service life. The deformable outer layer provides durable sealing during the treatment period, after which the ball sealer is intentionally designed to dislodge and be recovered or naturally removed. This disposable approach allows durable sealing when needed while enabling easy removal post-treatment, resolving the contradiction between sealing durability and dislodging ease.
Solution Approach 2:
The ball sealer is designed to be discarded after completing its sealing function. The deformable layer maintains strong adhesion to the perforation walls during treatment for durable sealing, but after treatment completion, the ball sealer is recovered or naturally dislodged through pressure changes or mechanical retrieval operations, thus achieving both durable action and easy recovery.
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 multilayered ball sealers efficiently adapt to irregular perforation shapes, providing improved sealing and maintaining structural strength to withstand wellbore pressures, while the deformable layers ensure effective sealing and controlled dislodging post-treatment.
Implementation Method 1
the deformable layers are deformable under pressure and deform when the multilayered ball sealers are seated on the perforation and pressure is applied to the wellbore
Implementation Method 2
A positive pressure differential is maintained between the well and the formation surrounding the well. When a ball sealer encounters an open perforation with such a pressure differential, i.e., higher pressure in the well than in the formation, the ball sealer seats itself on the perforation
Data Source
AI summary
A multilayered ball sealer having a deformable layer. The multilayered ball sealer has an outer or intermediate layer that is deformable under pressure. In the former, the deformable layer may be water-soluble or hydrolysable. In the latter, the outer layer is a sheath that contains the deformable layer and adapts to its shape. A multilayered ball sealer may be used as a diversion agent by being suspended in a fluid injected into a wellbore and applying pressure to deform the shape of the intermediate layer such that the multilayered ball sealer adapts to the shape of a perforation opening on which the multilayered ball sealer has seated.