Downhole Perforating Insert with Ejecting Core and Gel Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hydraulic fracturing methods rely on burstable disks that do not enhance the fracturing process and require additional barriers to protect from annulus pressures, which can lead to premature failure and malfunctions due to cement penetration.
Innovation Solution
A downhole apparatus with a core that seals a port in a completion string, disengaging as a projectile at threshold pressure to enhance fracturing, and a ported debris shield that equalizes annulus pressures and prevents cement setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a burstable disk is used to seal the casing hole, then the disk can block fluid flow while intact and rupture at a threshold pressure to allow treatment fluid to escape, but the disk does not enhance the fracturing process and merely acts as a non-reclosing pressure relief seal
Solution Approach 1:
The insert assembly is divided into separate functional components: a body portion that seals the port, a core that acts as a projectile, and a gel-filled chamber that prevents cement penetration. This segmentation allows each component to perform its specific function optimally, with the core providing fracturing enhancement while the body maintains sealing integrity until rupture.
Solution Approach 2:
The gel-filled chamber acts as an intermediary substance between the annulus and the port seal. The gel prevents cement from penetrating the seal chamber while allowing pressure equalization, thereby protecting the burstable disk from premature failure without compromising the sealing function.
2Reliability
If a barrier or cap is provided intermediate the disk and the wellbore annulus to protect the disk from annulus pressures, then the disk is protected from premature bursting, but the chamber formed between the barrier and the disk must be thoroughly sealed and kept at atmospheric pressure, which increases device complexity
Solution Approach 1:
The gel-filled chamber is extracted as a separate protective function from the traditional barrier-cap structure. The gel substance is placed in a chamber that opens to the annulus, eliminating the need for complex sealed barriers while still protecting the burstable disk from cement penetration and pressure differential effects.
Solution Approach 2:
The gel-filled chamber serves as a porous or permeable protective zone that allows pressure equalization between the annulus and the seal chamber. This eliminates the need for hermetic sealing while still providing protection against cement penetration and premature disk failure.
3Reliability
If the chamber seal is compromised and chamber pressure changes, then the disk's rupture pressure threshold changes which could result in premature failure or untimely bursting, but maintaining a sealed chamber increases the risk of cement penetration
Solution Approach 1:
The gel-filled chamber serves as an intermediary protective zone between the annulus and the port seal. The gel prevents cement from penetrating the seal chamber while allowing pressure equalization, thereby stabilizing the rupture pressure threshold of the burstable disk without compromising sealing integrity.
Solution Approach 2:
The gel substance changes the physical parameters of the chamber environment by preventing cement penetration and maintaining pressure equilibrium. This stabilizes the rupture pressure threshold of the burstable disk by eliminating harmful pressure variations that would otherwise occur due to cement infiltration.
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 core effectively initiates fractures at high speed, allowing deeper penetration of pressurized fluid without damaging the wellbore cement and operating effectively at greater depths, while the gel-filled chamber prevents cement setting and enhances fluid flow.
Implementation Method 1
The core has a first mode wherein the core prevents fluid passage through the body and a second mode wherein the core disengages from the body upon the treatment fluid reaching a threshold pressure and ejects from the body as a projectile
Implementation Method 2
treatment fluid is pumped under high pressure into the casing... pressurized treatment fluid exiting the port
Implementation Method 3
fracturing of the formation occurs when a treatment fluid is pumped under high pressure into the casing... to cause fractures in its strata
Implementation Method 4
The shield should form a chamber in the insert to retain a gel to obstruct entry of cement thereinto and to prevent setting of the cement which it contacts
Implementation Method 5
provide a ported debris shield that should allow annulus pressures to reach the core
Data Source
AI summary
An insert for perforating a subterranean formation sealingly engages a port in a production casing run into a wellbore intersecting the formation. The insert has a core where in a first mode it prevents fluid passage through the insert, and a second mode where the core disengages from the insert upon a treatment fluid reaching a threshold pressure in the casing, and ejects from the insert as a projectile to initiate and contribute to the fracture and stimulation of the formation by the pressurized treatment fluid exiting the port. The insert has a chamber which is filled with a gel that prevents wellbore cement from setting and is covered by a perforated debris shield that permits the equalization of pressure between the chamber and the annulus between the casing and wellbore.