BOP Testing Collar for Subsea Wellhead Pressure Seals
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Solution Overview
Problem
Current methods for testing blowout preventers (BOPs) in subsea wellheads require abandoning drilling operations and pulling the drill string back to surface, which is time-consuming and inefficient, especially in deep water, and can cause damage to the wellhead bore, making it difficult to form adequate seals post-drilling.
Innovation Solution
An apparatus comprising a drilling tool with fluid ports and a mateable collar that blocks these ports, allowing the tool and wear bushing to remain in the wellhead during BOP testing, along with a method of pumping fluid into a chamber between the BOP and the collar to build pressure and test the seals, enabling in-situ testing without recovering the full drill string.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drill string is pulled back to surface for BOP testing, then the BOP can be tested, but rig time is lost and wellhead bore may be damaged
Solution Approach 1:
The invention separates the BOP testing function from the drill string recovery operation. By using a collar that can be run independently on a separate string to block the fluid ports, the testing function is segmented from the drilling operation, allowing the drill string to remain in place while the BOP is tested through the collar interface
Solution Approach 2:
The collar acts as an intermediary device between the external testing equipment and the BOP. It provides a interface that allows pressure testing to be conducted without requiring the drill string to be recovered, mediating the testing process while the drill string remains in the well
2Reliability
If the drill string is pulled back to surface for BOP testing, then the BOP can be tested, but wellhead bore may be damaged
Solution Approach 1:
The invention separates the testing function from the drill string recovery operation. By using a collar that can be run independently on a separate string to block the fluid ports, the testing function is segmented from the drilling operation, allowing the drill string to remain in place while the BOP is tested through the collar interface
Solution Approach 2:
The collar is run into position beforehand to block the fluid ports before testing begins. This preliminary action of securing the collar in place prevents any potential damage to the wellhead bore during the testing process, as the collar provides a protected interface for pressure application
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 allows for efficient BOP testing in situ, saving rig time and preventing wellhead damage, as the drilling tool and wear bushing can remain in the wellhead, and enables effective pressure testing without the need for full drill string recovery, enhancing safety and operational efficiency.
Implementation Method 1
the fluid ports in the drilling tool are blocked by the collar when the collar is mated with the drilling tool
Implementation Method 2
a method of pumping fluid into a chamber between the BOP and the collar to build pressure and test the seals
Data Source
AI summary
An apparatus including a drilling tool for locating in a wellhead has fluid ports therein. The apparatus further includes a collar which is mateable with the drilling tool, such that the fluid ports in the drilling tool are blocked by the collar when the collar is mated with the drilling tool. The drilling tool can be a bit runnable drill string tool. The apparatus may also include a bit runnable wear bushing. The apparatus can advantageously be used to perform a method of testing a blowout preventer (BOP) on a subsea wellhead.