Safeguarding Well Integrity: A Success Story!

Maintaining well integrity is of utmost importance to ensure safe operations throughout the entire lifespan of a well. Among critical well integrity challenges, sustained casing pressure (SCP) stands out as a significant issue related to the failure of well barrier elements such as casing and cement and is essential to monitor and control, as it can indicate potential well integrity issues that may lead to well control problems or leaks. 

In the presence of SCP, localized changes in temperature and acoustic signals generated by the fluid or gas passing through the leak can be observed. By monitoring temperature changes and analyzing the acoustic signals detected by a fiber optic cable, the presence and location of the SCP can be identified.

A wet gas producer well in South America was experiencing SCP. A slickline survey utilizing AP Sensing's Distributed Temperature Sensing (DTS) and Distributed Acoustic Sensing (DAS) solutions was deployed by our partner Expro to identify the source of the SCP. In addition to deploying the fiber optic cable, Expro provided rapid data evaluation through onsite data processing, enabling the delivery of quick results within hours of conducting the survey!

The integration of Expro's Distributed Fiber Optic Sensing-enabled slickline and powerful software, alongside AP Sensing's DTS and DAS interrogator units, enabled the operator to properly locate the source of the SCP, identify the path of fluid behind the casing, and identify the fluid entry point right after the DTS and DAS data acquisition. The primary annulus well integrity issue was identified to be water entering the well at the 9-5/8" shoe. 

Localizing and addressing SCP is crucial for ensuring wellbore integrity, preventing well control incidents, protecting the environment, and maintaining operational efficiency. By identifying the source of SCP, operators can take appropriate measures to address underlying issues and mitigate potential risks associated with casing pressure buildup.