Lifting Coupling for Dual-Activity Drilling Hang-Off
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Solution Overview
Problem
In offshore drilling, the existing methods for hang-off and pickup operations of oilfield tubulars often result in compromised connections due to suboptimal torque application, leading to potential loss of the casing string if the connection fails during transfer between drilling rigs.
Innovation Solution
A lifting coupling system with a first member and a second member, featuring engaging hooks and lugs, allows for secure weight transmission without substantial torque transmission, enabling reliable hang-off and pickup operations by decoupling the members without torque transfer, facilitating safe transfer and reconnection of tubulars between rotary stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If suboptimal torque is applied to establish connection between drill pipe and casing string, then hang-off and pickup operations can be performed, but connection strength is compromised and risk of connection failure increases
Solution Approach 1:
A make-up tool is introduced as an intermediary device between the drill pipe and casing string to apply optimal make-up torque during connection. This tool ensures that the connection achieves full strength while still allowing for controlled disconnection during break-out operations, resolving the contradiction between operational ease and connection strength.
Solution Approach 2:
The system changes the torque parameter dynamically - applying high torque (70,000 ft-lbs or more) during make-up to ensure strong connection, and then controlling break-out torque to be lower for safe disconnection. This parameter transformation allows both strong connection and operational flexibility.
2Strength
If high torque is applied to establish connection between drill pipe and casing string, then connection strength is maximized, but equipment requirements and operational complexity increase
Solution Approach 1:
The make-up tool serves as a specialized intermediary that concentrates the torque application function. Rather than requiring the entire drilling equipment to handle high torque continuously, the make-up tool is specifically designed for this purpose, simplifying the overall system while maintaining connection strength.
3Productivity
If casing string is transferred between rotary stations using conventional methods, then dual-activity drilling can be performed, but risk of connection failure and tubular loss increases
Solution Approach 1:
The make-up tool acts as a reliable intermediary that ensures optimal connection every time the casing string is transferred between rotary stations. This consistent proper make-up procedure maintains connection reliability while enabling the productivity benefits of dual-activity drilling.
Solution Approach 2:
The system applies make-up torque beforehand to ensure the connection is fully strengthened before the casing string is subjected to the stresses of transfer and deployment. This preventive measure cushions against potential connection failure during subsequent operations.
Data Source
AI summary
Methods and apparatus for running a tubular into a wellbore. The method includes attaching a first member of a lifting coupling to a first tubular, and attaching a second member of the lifting coupling to a second tubular. The second tubular extends downward through an opening of a rotary station. The method also includes connecting together the first and second members of the lifting coupling, such that a weight of the second tubular is transmitted via the lifting coupling to the first tubular. The method further includes lowering the lifting coupling, the second tubular, and at least a portion of the first tubular through the opening, and disconnecting the second member from the first member. The method additionally includes moving the second member of the lifting coupling and the second tubular laterally, away from the opening.