Inflatable Packer Element With Pressure-Actuated Valve
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Solution Overview
Problem
Current methods for fracturing subterranean formations in wellbores face challenges in efficiently creating and maintaining fractures, as they rely on high-pressure fluid injection without a reliable sealing mechanism to optimize fracture propagation and proppant deployment.
Innovation Solution
An inflatable packer system integrated with an earth boring bit assembly, featuring a seal element that expands radially upon increased pressure, an inlet valve with a piston and spring mechanism, and a fracturing port, allowing selective deployment of fracturing fluid to create and maintain fractures in the formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-pressure fluid injection is used for fracturing, then fracture propagation is enabled, but reliable sealing mechanism is lacking
Solution Approach 1:
The patent employs a flexible packer element comprising a radially outwardly expandable membrane that forms a seal between the drill string and wellbore wall. This flexible membrane structure can conform to the wellbore geometry and provide reliable sealing under high-pressure fracturing conditions, directly addressing the sealing mechanism deficiency in conventional high-pressure fracturing methods
2Strength
If pressure is increased above drilling levels for fracturing, then fracture creation is enhanced, but pressure control becomes challenging
Solution Approach 1:
The system employs a pressure-actuated inlet valve with a piston and spring mechanism that automatically opens when fracturing pressure is reached and closes when pressure drops. This self-regulating mechanism eliminates the need for external valve control, enabling automatic pressure management during fracturing operations and simplifying operator control while maintaining enhanced fracture creation capability
Solution Approach 2:
The inlet valve mechanism provides inherent feedback control by responding to pressure differential across the piston. When pressure exceeds the spring bias force, the valve opens to allow fluid into the packer; when pressure drops, the spring closes the valve. This feedback mechanism automatically maintains pressure within the desired range for fracture creation
3Reliability
If seal element expands radially into wellbore wall, then sealing engagement is achieved, but device complexity increases
Solution Approach 1:
The packer element is inflated using hydraulic pressure from the drilling fluid itself. The fluid pressure acts on the membrane to cause radial expansion and sealing engagement with the wellbore wall. This eliminates the need for separate mechanical expansion mechanisms, reducing device complexity while achieving reliable sealing engagement through pressure-driven inflation
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 system effectively seals the wellbore, enables controlled fracturing fluid delivery, and enhances fracture creation and propagation by maintaining pressure above drilling levels, improving fracture extension and proppant placement efficiency.
Implementation Method 1
a spring in an end of the cylinder that biases the piston towards the end of the cylinder facing the bore in the drill string
Implementation Method 2
the seal element expands radially outward into sealing engagement with a wall of the wellbore
Data Source
AI summary
A system for use in a subterranean wellbore includes an earth boring bit on a lower end of a drill string, and an inflatable packer system. The packer system includes a pressure activated inlet valve that regulates pressurized fluid from within the drill string to the packer for inflating the packer. The inlet valve opens above a pressure used for drilling and includes a piston and spring disposed in a cylinder; the spring provides a biasing force against the piston and positions the piston between the annulus and an inlet port to the packer. When inflated, the packer extends radially outward from the drill string and into sealing engagement with an inner surface of the wellbore.