IOGP Well Control Incident Lesson Sharing

Abnormal formation pressure encountered while drilling due to offset water injection wells

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.

IOGP recently shared well safety alert number 350: Abnormal formation pressure encountered while drilling due to offset water injection wells.

We have created a short explanation about how it relates back to IWCF’s Drilling Well Control syllabi.


This lesson details that while drilling, abnormal formation pressures were encountered because offset water injection wells had not been correctly shut in ahead of drilling activity. It was further determined that the water injector wells had been operating in excess of their design limits which further impacted formation pressures encountered during the drilling operation. As a result, the predicted pore pressures were higher than expected causing a kick to be taken while drilling exceeding the Formation Integrity Test (FIT). The well was successfully killed using the Driller’s Method.

What went wrong?

  • Offset injection well design and operating limits were exceeded.
  • PPFG prediction did not consider the potential impact from out-of-zone-injection on offset wells.
  • Offset water injection wells were not correctly assessed for shut-in requirements ahead of drilling activity.
  • Utilising the auto driller in constant ROP mode impeded the ability to identify a drilling break at 3480m, i.e. there was reduction in WOB and torque rather than increase in ROP.
  • Flow paddle alarm setting point at +- 5% was too wide to provide an alarm at the influx rate of 50 bph equivalent to an increase in flow out of 2%.
  • The shut in of the well was delayed due to conducting an additional flow check adding to the influx volume. There were positive indications of an influx through the increase in
  • PVT increase and flowback fingerprint when pumps were shut down.

Corrective actions and recommendations

  • Update guidance for operating injection wells including methodology for setting bottom hole injection pressure limits.
  • Define how to identify a drilling break when drilling in “auto drill” mode with constant ROP.
  • Perform flow paddle calibration at the casing shoe prior to drilling the hole section to define the appropriate minimum alarm setting at the planned flow rate.
  • Revise Well Control Shut In procedures to prompt shutting-in the well without a flow check in the case of a positive indication of an influx.
  • Review frequency and method of kick detection drills to verify the response of the driller, mud loggers and remote monitoring team.

How does this relate to IWCF syllabi?

We have listed several syllabus items related to issues seen in this incident.

Kick warning signs while drilling and/or circulating.
This syllabus item describes how kick warning signs should be registered and assessed. It is important to consider changing trends, not isolated parameters.

DR-SF-PNP-06.01.0 3
Actions to take after recognising a kick warning sign.
This syllabus item outlines how to flow check the well to evaluate the warning signs and communicate with the team.

Kick indicators and the importance of early kick detection.
This syllabus item provides candidates with knowledge on how to detect a kick early and minimise the kick volume.

The interpretation of well flow-back (for example: ‘finger-printing’ and trend analysis).
This syllabus item describes the practices to follow to differentiate between normal well behaviour and potential kick indicators. This was a key factor in the incident described above.

The principles of kick margin/tolerance/intensity and how it is applied to well operations.
This syllabus item describes how candidates should identify the factors affecting kick tolerance and their impact on well operations.

A suitable shut-in procedure if a primary barrier fails.
This syllabus item describes how to recognise primary barrier failure and select a procedure which is known to the crew, possible to use and regularly practised. This helps the drilling crew to minimise the kick volume.

The steps to secure a well using the hard shut-in method.
This syllabus item describes the key steps while shutting-in a well using the hard shut-in method.

How to confirm if well closure is successful and the actions to take if not.
This syllabus item that relates to the ability to confirm shut-in to prevent additional influx entering the well.

All IOGP Well Control Incident Lesson Sharings

Visit the IOGP website for a full list of all lessons shared to date: