IOGP Well Control Incident Lesson Sharing

BOP Test Assembly Ejected from Well

Following well kill operations, the BOP was tested with a tubing hanger (BOP test assembly). Upon conclusion of BOP testing, the tubing hanger was being disengaged when it was ejected from the well due to the residual energy below. The well was secured by closing the blind rams.

The Wells Expert Committee/Well Control Incident Subcommittee believes that this incident description contains sufficient lessons to be shared with the industry. We further encourage the recipients of this mail to share it further within their organization.

What happened?:

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.

What Went Wrong?:

Failure to demonstrate zero energy below tubing hanger prior to disengaging the tubing hanger.

Corrective Actions and Recommendations:

Reinforce the use of procedures to verify process safety, including site supervisor verification of equipment alignment and procedure adherence.

safety alert number: 320
IOGP Well Control Incident Lesson Sharing


Whilst every effort has been made to ensure the accuracy of the information contained in this publication, neither the IOGP nor any of its members past present or future warrants its accuracy or will, regardless of its or their negligence, assume liability for any foreseeable or unforeseeable use made thereof, which liability is hereby excluded. Consequently, such use is at the recipient's own risk on the basis that any use by the recipient constitutes agreement to the terms of this disclaimer. The recipient is obliged to inform any subsequent recipient of such terms.
This document may provide guidance supplemental to the requirements of local legislation. Nothing herein, however, is intended to replace, amend, supersede or otherwise depart from such requirements. In the event of any conflict or contradiction between the provisions of this document and local legislation, applicable laws shall prevail.

City Tower, 40 Basinghall Street
Level 14
London, London EC2V 5DE
United Kingdom