Pressure Perforated Well Casing Collar Rupture Mechanism
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Solution Overview
Problem
Existing well casing completion methods face inefficiencies and high costs due to the need for complex systems and high pump horsepower requirements, particularly in achieving effective perforation and fracturing of hydrocarbon production zones.
Innovation Solution
A pressure perforated well casing collar with internal threads and strategically cut perforation grooves that rupture at a higher pressure than the joint burst rating, allowing for efficient fracturing fluid flow without damaging adjacent collars, eliminating the need for additional perforation tools and reducing completion costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional well casing completion methods are used with complex perforation tools, then effective perforation and fracturing can be achieved, but pump horsepower requirements and operational complexity increase significantly
Solution Approach 1:
Pressure perforation grooves are pre-cut into the casing collar during manufacturing, creating predetermined weak points that will rupture at specific pressure thresholds. This preliminary action eliminates the need for downhole perforation tools and reduces pump horsepower requirements during the fracturing operation, as the grooves are already prepared to fail at the desired location when pressure reaches the rupture threshold.
Solution Approach 2:
The invention changes the physical state and structural integrity of the casing collar by introducing grooves with specific depth and geometry parameters. These grooves are designed with controlled dimensions that determine their rupture pressure, allowing the collar to transition from a intact structural component to a controlled rupture point at a predetermined pressure level, thereby enabling perforation without high-power equipment.
2Reliability
If additional perforation tools and equipment are deployed, then perforation can be achieved, but completion costs and operational complexity increase
Solution Approach 1:
The casing collar performs the perforation function itself through the pre-cut grooves that rupture under pressure. The collar is self-sufficient and does not require external perforation tools, wirelines, or specialized equipment to create perforations. The structure inherently provides the perforation capability through its own design, eliminating the need for additional tools and simplifying the completion system.
Solution Approach 2:
The invention extracts the perforation function from separate downhole tools and integrates it directly into the casing collar structure itself. By incorporating the grooves into the collar during manufacturing, the perforation capability is built-in, removing the need for dedicated perforation equipment and reducing overall system complexity.
3Reliability
If pressure perforation grooves extend through the entire sidewall thickness, then complete perforation is achieved, but collar burst pressure integrity is compromised
Solution Approach 1:
The grooves are designed with non-uniform depth characteristics, extending partially through the sidewall thickness but not completely. This local quality variation creates a controlled weak point that preferentially ruptures under pressure while leaving sufficient material to maintain overall collar strength and burst pressure integrity. The groove depth is optimized to provide perforation capability without compromising structural integrity.
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
This solution enables more efficient and cost-effective well completion and fracturing by reducing pump horsepower requirements by up to 60%, simplifying operations, and providing flexibility in fracture location, while ensuring robustness and safety in both vertical and horizontal wellbores.
Implementation Method 1
whereby isolated fluid pressure applied within the pressure perforated well casing collar will cause the sidewall bottom material in the at least one pressure perforation groove to rupture
Data Source
AI summary
Pressure perforated well casing collars have at least one pressure perforation groove cut to a consistent depth in an a sidewall of the well casing collar with sidewall bottom material at a bottom of the groove. The sidewall bottom material ruptures at a predetermined fluid pressure greater than a burst pressure rating of plain casing joints connected to the well casing collars to assemble a well casing string.