Riser Weak Link Pressure Balancing for Accurate Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional riser weak links struggle to accurately separate at predetermined tensions due to variable well pressure, leading to limited operational utilization or failure to protect the system from excessive tension, which can result in environmental hazards.
Innovation Solution
A pressure-balanced riser weak link system that utilizes a pressure application device to counteract well pressure forces, allowing the connection device to primarily experience tension from the surface vessel, enabling accurate rating and separation of the upper and lower housings at predetermined forces, using a pressure balance piston and latch device to manage well pressure and apply a coupling force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional weak link uses studs to connect upper and lower housings, then the connection can be simple and reliable, but the separation force is affected by variable well pressure making accurate separation at predetermined tension difficult
Solution Approach 1:
The pressure application device applies a preliminary counteracting force to offset well pressure before the separation event occurs. The piston is pre-positioned and the pressure application mechanism is activated in advance to balance the well pressure, ensuring that the studs only experience the applied tension plus a controlled additional force, not the variable well pressure
Solution Approach 2:
A pressure application device with a piston acts as an intermediary between the well pressure and the stud connection. The piston transfers and balances the well pressure separately, so the studs only need to withstand the controlled applied tension, decoupling the separation force from variable well pressure
2Reliability
If the weak link is designed to separate at low tension, then system protection is improved, but operational utilization is limited due to high well pressure
Solution Approach 1:
The pressure application device applies a preliminary counteracting force to offset well pressure before the separation event occurs. The piston is pre-positioned and the pressure application mechanism is activated in advance to balance the well pressure, ensuring that the studs only experience the applied tension plus a controlled additional force, not the variable well pressure
Solution Approach 2:
The system dynamically adjusts the separation force by controlling when and how the pressure application device activates. During normal operation, the device balances well pressure to allow full operational utilization. When excessive tension is detected, the device fails in a controlled manner to enable separation, adapting to changing operational conditions
3Productivity
If the weak link is designed to separate at high tension, then operational utilization is improved, but system protection fails at low pressure conditions
Solution Approach 1:
The pressure application device applies a preliminary counteracting force to offset well pressure before the separation event occurs. The piston is pre-positioned and the pressure application mechanism is activated in advance to balance the well pressure, ensuring that the studs only experience the applied tension plus a controlled additional force, not the variable well pressure
Solution Approach 2:
The system incorporates feedback through the controlled failure mechanism of the pressure application device. When excessive tension is applied, the device fails in a predictable manner that triggers separation, providing feedback about the tension state and enabling the system to respond appropriately to protect against over-tensioning
4Measurement precision
If a pressure application device is added to balance well pressure, then separation accuracy is improved, but device complexity increases
Solution Approach 1:
The pressure application device uses hydraulic or pneumatic principles where well pressure acts on a piston to generate a counteracting force. This leverages the existing well pressure rather than requiring an active pressure generation system, reducing complexity while achieving pressure balancing
Solution Approach 2:
The pressure application device uses the well pressure itself to generate the counteracting force, rather than requiring an external power source or active control system. The well pressure serves dual purposes: it is both the force to be balanced and the power source for the balancing mechanism
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 ensures the connection device can accurately separate the upper and lower housings at predetermined tensions, maximizing operational utilization and preventing environmental hazards by isolating the riser contents during separation.
Implementation Method 1
The pressure application device may utilise well pressure to apply the coupling force to the upper housing
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A riser weak link (10) is described. The riser weak link comprises an upper housing (16) for connecting to a riser upper section (12), a lower housing (18) for connecting to a riser lower section (14), at least one connection device for releasably connecting the upper and lower housings, and a pressure application device (24) adapted to apply a coupling force to the upper housing to at least partially counter a separation force applied, in use, by well pressure, the well pressure separation force acting to separate the upper and lower housings.