We monitor IOGP’s ‘Well control Incident lesson sharing’ which is a regular email that alerts the industry to recent incidents with the hope of sharing knowledge and preventing future well control incidents.
A recent lesson (IOGP Well Control Incident Lesson Sharing 21-2 – issued on 23 February 2021) related to a BOP test assembly being ejected from the well.
Using the incident lesson sharing, we have created a short explanation and how it relates back to IWCF syllabi.
During a workover operation the well had been killed using kill weight fluid and a tubing hanger (BOP test assembly) had been installed prior to testing the rig’s BOP. Following the BOP test the tubing hanger was being disengaged when the hanger and handling joint were ejected from the well. The well was secured using the BOP’s blind rams; returns from the well were routed through the choke line to the rig’s mud gas separator until well pressure was relieved.
Failure to demonstrate zero energy below tubing hanger prior to disengaging the tubing hanger.
Reinforce the use of procedures to verify process safety, including site supervisor verification of equipment alignment and procedure adherence.
This incident relates to a completion operation, and IWCF’s WIPC syllabi has a key focus on promoting safe working practices, and the importance of identifying and correctly responding to risk.
The below WIPC syllabus outcomes may contain principles relevant to this type of incident.
An element of the issue relates to identifying the hazard of trapped pressure below the tubing hanger and consequences of trapped pressure when unlocking the hanger.
Identifying and responding to risk is emphasised in WIPC syllabus outcome WI-SF-COM-02.03.01.
| Syllabus description | Level 2 outcome | Level 3 outcome | Level 4 outcome |
| Risk management principles and practices. | Describe the principles and practices of risk management including:
|
Explain the principles and practices of risk management including:
Actions to mitigate and control risk. |
Explain how and when to use risk management principles and practices to reduce the probability and the consequences of a well intervention pressure control incident. |
This incident also happened during pressure testing a rig BOP stack before pulling the upper completion. Hazards were created by the pressure testing. These risks are highlighted in IWCF syllabus outcome WI-SF-COM-05.03.02
| Syllabus description | Level 2 outcome | Level 3 outcome | Level 4 outcome |
| Intervention (wireline, coiled tubing and snubbing) BOP pressure tests and function tests. | Explain how intervention BOPs are pressure tested and function tested. | Explain how to do pressure tests and function tests on any type of intervention BOP.
Explain the hazards and limits of low and high-pressure tests. |
From a given situation, verify how to do pressure tests and function tests on any type of intervention BOP and assess if the test results are acceptable.
Explain the hazards and limits of low and high-pressure tests. |
You can find this and previous examples of IOGP’s ‘lesson shared’ on the IWCF website here. In the next newsletter we will focus on IOGP WCI Lesson Sharing 21-04 – Gas release during abandonment operations.
Visit the IOGP website for a full list of all lessons shared to date: https://safetyzone.iogp.org/WCILessonsShared/WCILS/main.asp
