Window Mill Piston Shear Pin Hydraulic Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current borehole sidetrack milling assemblies rely on expensive rupture discs and limited-pressure braided hoses to isolate and deliver pressure for anchor setting, which increases costs and restricts available setting pressure.
Innovation Solution
A piston with a hydraulic line and shear pins is used to block and then open window mill circulation ports, eliminating the need for rupture discs and allowing high-pressure tubing for increased pressure rating, enabling anchor setting without rupture discs and hoses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rupture discs and braided hoses are used to isolate window mill circulation ports for anchor setting, then the anchor can be set hydraulically, but the cost increases and the pressure rating is limited
Solution Approach 1:
The invention extracts and eliminates the rupture disc from the system by using a piston that can be mechanically moved to open circulation ports. The piston is held in position by shear pins that break at a predetermined force, replacing the rupture disc's pressure-based isolation mechanism with a force-based mechanical release mechanism, thereby eliminating cost and pressure rating limitations associated with rupture discs and braided hoses
Solution Approach 2:
The invention introduces a piston as an intermediary component between the hydraulic line and the window mill circulation ports. This piston acts as a controllable valve mechanism that can be positioned to block or open flow paths, replacing the passive rupture disc isolation with an active mechanical control system that enables high-pressure operation without requiring expensive rupture discs and braided hoses
2Reliability
If braided hoses are used to deliver hydraulic pressure for anchor setting, then the anchor can be set, but the pressure rating is limited and costs increase
Solution Approach 1:
The invention extracts and eliminates the braided hose from the hydraulic pressure delivery system by using a rigid piston mechanism within the window mill housing. The piston is directly actuated by hydraulic pressure through a hydraulic line, eliminating the need for flexible braided hoses and their associated pressure rating limitations, thereby enabling high-pressure anchor setting operations
Solution Approach 2:
The invention replaces the flexible mechanical braided hose system with a rigid piston-based mechanical system. The piston is driven directly by hydraulic pressure and uses shear pins as a mechanical fuse to control the opening of circulation ports, substituting the pressure-limited flexible hose system with a high-pressure capable rigid mechanical system
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 reduces costs by eliminating rupture discs and braided hoses, enabling higher pressure ratings for anchor setting and efficient window mill operation, facilitating lateral borehole exits with improved pressure management.
Implementation Method 1
pressure is delivered through the running string and into the widow mill that is releasably secured to the top of the whipstock. The anchor has to be set before the mill assembly can be sheared loose from the whipstock ramp by applied axial force or rotation. In order to deliver the needed pressure at the anchor to set the anchor, the circulation ports in the window mill are typically isolated with a rupture disc.
Implementation Method 2
The piston is held in position with one or more shear pins or the like and when the pressure has been increased to set the anchor and then further increased to break the shear pin or the like the piston moves into a larger bore to expose ports to allow flow into the window mill circulation ports
Data Source
AI summary
A piston has a hydraulic line going through it and is held in position with one or more shear pins or similar breakable retainers. The piston blocks the flow to the window mill circulation ports until a pressure level is reached that breaks the breakable members to allow the piston to move. The piston moves into a larger bore to allow bypass flow through lateral openings. The piston is captured in the larger diameter chamber after passing the lateral openings. Piston movement pushes out some of the high pressure tubing through the window mill where initial rotation of the window mill along the whipstock face causes the extending tubing to be ground off. A rupture disc and high pressure hoses are no longer needed for a significant cost savings from prior designs.