Adjustable Buoyancy Chamber for Offshore Wellhead Tension Control
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Solution Overview
Problem
Existing offshore drilling systems are inflexible and costly, particularly in deepwater operations, as they require large-scale conventional platforms and lengthy delays between investment and profit, and lack the ability to adjust wellhead depth and tension during exploration and production, making them inefficient for smaller fields and challenging environments.
Innovation Solution
An adjustable buoyancy chamber system that allows for varying the height or depth of the well terminal member and maintaining constant vertical tension, incorporating a well casing connected to an adjustable buoyancy chamber with lower and upper connecting members, and utilizing lateral stabilizers and anchoring means to manage horizontal forces, enabling flexible operation in both deep and shallow waters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional large-scale platforms are used for offshore drilling, then stability and cost-effectiveness are improved, but flexibility and adaptability to different field sizes are worsened
Solution Approach 1:
The buoyancy chamber is designed with adjustable volume capability, allowing the system to dynamically adapt its buoyant force to match different wellhead weights and operational requirements. This enables a single system design to serve both large and small fields effectively
Solution Approach 2:
The system changes the physical parameter of buoyant force by adjusting the chamber volume, allowing adaptation to different operational conditions and field sizes without requiring complete system replacement
2Device complexity
If fixed-depth wellhead systems are used, then structural simplicity is improved, but ability to adjust wellhead depth during operations is worsened
Solution Approach 1:
The wellhead position is made dynamically adjustable through the buoyancy chamber volume control mechanism, allowing depth modification during exploration and production phases without complex mechanical repositioning systems
Solution Approach 2:
The adjustment mechanism is separated from the wellhead structure itself and implemented through the independent buoyancy chamber, keeping the wellhead design simple while providing adjustment capability through an external control system
3Productivity
If conventional drilling systems are used, then initial exploration capability is improved, but ability to perform maintenance and adjustments during production is worsened
Solution Approach 1:
The system maintains dynamic adjustability during the production phase, allowing wellhead repositioning and tension adjustments without requiring retrieval to surface, thereby enabling maintenance operations in situ
Solution Approach 2:
The buoyancy chamber system enables self-service maintenance capabilities by allowing operators to adjust wellhead position and tension using the same mechanism that deployed the system, without requiring external heavy equipment or ROV intervention
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
Enables flexible and efficient operation throughout exploration and production phases, reducing costs and delays by allowing real-time adjustments to wellhead depth and tension, suitable for both deep and shallow water environments, and facilitating maintenance without the need for remote-operated vehicles.
Implementation Method 1
an adjustable buoyancy chamber (9) capable of varying its buoyant force to adjust the depth of a well terminal member (14) and maintain constant vertical tension on a well casing (2)
Data Source
AI summary
A system and method of establishing an offshore exploration and production system is disclosed, in which a well casing is disposed in communication with an adjustable buoyancy chamber and a well hole bored into the floor of a body of water. A lower connecting member joins the well casing and the chamber, and an upper connecting member joins, the adjustable buoyancy chamber and a well terminal member. The chamber's adjustable buoyancy enables an operator to vary the height or depth of the well terminal member, and to vary the vertical tension imparted to drilling and production strings throughout exploration and production operations. Also disclosed is a system and method of adjusting the height or depth of a wellhead while associated vertical and lateral forces remain approximately constant. A variety of well isolation members, lateral stabilizers and anchoring means, as well as several methods of practicing the invention, are also disclosed.