Port Sub Delayed Opening Sequence
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Solution Overview
Problem
Existing port subs used in downhole operations cannot withstand the high pressures during casing pressure tests, leading to premature opening of flow ports and increased costs due to the need for dissolvable balls and ball seats, which also slow down operations and can leave debris in the wellbore.
Innovation Solution
A port sub with a low-pressure port assembly and a high-pressure port assembly, where the low-pressure inner layer ruptures at a lower pressure than the high-pressure inner layer, allowing controlled opening of flow ports, and a dissolve fluid is used to accelerate the opening of standard flow ports after the pressure test.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single-layer port assembly is used in existing port subs, then the structure is simple, but it cannot withstand high pressures during casing pressure tests leading to premature opening of flow ports
Solution Approach 1:
The port assembly is divided into multiple independent layers (first layer, second layer, third layer) with different rupture pressures. Each layer serves as a separate pressure barrier that can be selectively breached, allowing the system to withstand high test pressures while controlling when flow ports open. The first layer ruptures at lower pressure to allow testing, while the second layer maintains closure until higher pressures are applied.
Solution Approach 2:
The port assembly uses composite construction with multiple materials having different mechanical properties and rupture thresholds. Each layer is made from materials selected for specific pressure resistance characteristics, creating a composite structure that provides progressive failure modes rather than single-point failure, enabling controlled opening sequences.
2Reliability
If dissolvable balls and ball seats are used to prevent premature opening, then flow ports can be protected during pressure tests, but operation time increases and costs increase
Solution Approach 1:
The invention removes the dissolvable ball and ball seat components from the system entirely. Instead, the layered port assembly structure itself provides the protection mechanism through its pressure-resistant layers that prevent premature opening during testing, eliminating the need for separate protective devices and the time required to deploy and retrieve them.
Solution Approach 2:
The port assembly is self-regulating through its layered structure that automatically responds to pressure conditions. The layers rupture at predetermined pressures without requiring external intervention such as dissolvable balls, providing automatic protection and opening based on pressure thresholds alone, thus eliminating additional operational steps.
3Reliability
If dissolvable balls are used to stop fluid flow, then premature opening can be prevented, but debris is left in the wellbore
Solution Approach 1:
The invention eliminates dissolvable balls from the system, replacing them with a fixed layered port assembly structure. This removal prevents the generation of debris in the wellbore while maintaining flow control capabilities through the pressure-dependent rupture of the layered structure.
Solution Approach 2:
Instead of using disposable dissolvable balls that create debris, the invention employs a reusable layered port assembly where only the specific layer corresponding to the test pressure is consumed through controlled rupture, while other layers remain intact for future operations, reducing overall debris generation.
4Ease of operation
If flow ports are opened during pressure testing, then hydraulic actuated tools can be actuated, but premature actuation occurs due to pressure spikes
Solution Approach 1:
Different layers of the port assembly have different rupture pressure characteristics tailored to specific operational requirements. The first layer is designed for lower pressure operations allowing tool actuation, while the second layer is designed for higher pressure testing, creating localized quality variations that prevent premature actuation while enabling controlled operation.
Solution Approach 2:
The port assembly provides dynamic response to pressure changes through its layered structure. Rather than a single static threshold, the system adapts its opening behavior based on the pressure level, with different layers becoming active at different pressure stages, allowing controlled actuation while preventing premature opening during pressure spikes.
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
Enables controlled and selective opening of flow ports, reducing the risk of premature actuation of hydraulically actuated tools and minimizing debris in the wellbore, while allowing for efficient completion of pressure tests without the need for dissolvable balls and ball seats.
Implementation Method 1
a low-pressure inner layer having a first rupture pressure; and a low-pressure outer layer... a high-pressure inner layer having a second rupture pressure, the second rupture pressure being greater than the first rupture pressure
Implementation Method 2
a dissolve fluid is used to accelerate the opening of standard flow ports after the pressure test
Data Source
AI summary
A port sub comprises one or more standard flow ports, each having a low-pressure port assembly positioned therein to, and at least one control flow port having a high-pressure port assembly positioned therein. The low-pressure port assembly comprises an inner layer having a first rupture pressure and an outer layer configured to remain intact upon the rupturing of the inner layer. The high-pressure port assembly comprises an inner layer having a second rupture pressure that is greater than the first rupture pressure. The high-pressure port assembly is configured to be broken through upon the rupturing of its inner layer to allow fluid flow through the at least one control flow port, thereby allowing a dissolve fluid to flow therethrough to facilitate the disintegration of the outer layer of the low-pressure port assembly to open the one or more standard flow ports.