A well maintains both internal and external pressure integrity primarily through the casing string. For common casing sizes such as 146 mm, 168 mm, and 178 mm, the steel is typically pressure-tested to 10–14 MPa, confirming its role as the primary pressure-containing barrier. Cement, while important, is not designed to serve as the main barrier for long-term pressure integrity.

The Challenge of Aging Wells

After 15–17 years of operation, it is not uncommon for casing strings to lose pressure integrity due to corrosion, wear, and long-term exposure to harsh downhole conditions. At that stage, the challenge is not simply how to seal the damaged interval—but how to restore integrity in a way that delivers a guaranteed long-term result.

Limitations of Conventional Cement Squeezing

Early in our work, RML specialists recognized that cement squeezing alone cannot reliably guarantee long-term isolation. While widely used, cement presents several inherent limitations:

  • Susceptibility to corrosion and chemical degradation
  • Potential for loss of strength over time
  • Risk of cracking under thermal and mechanical stress
  • Difficulty achieving a uniform cement sheath behind casing in real well conditions

These factors introduce uncertainty, particularly in mature wells where reliability is critical.

Engineered Casing Repair as a Reliable Alternative

In response, RML focused on developing engineered casing repair technology designed to provide consistent, pressure-tested results.

To date, 273 Casing Patch systems have been successfully deployed across multiple models, including:

  • RML Casing Patch 1.0
  • RML Casing Patch 1.5
  • RML Casing Patch 2.0
  • RML Casing Patch 3.0 (latest generation)

The results are clear:

  • 100% deployment success rate
  • Patches installed more than five years ago continue to operate successfully
  • Verified casing integrity through pressure testing at handover

This track record demonstrates that engineered mechanical solutions can deliver the long-term reliability that conventional methods often cannot.

Cost Efficiency and Operational Confidence

Beyond reliability, the Casing Patch system is consistently more cost-effective than cement squeezing. By reducing the need for repeat interventions and minimizing operational uncertainty, operators benefit from:

  • Lower overall remediation costs
  • Reduced downtime
  • Greater confidence in long-term well performance