Featuring Dr. Jarrett Wise, research engineer for the USDA, and Les Skinner, a petroleum engineer with 50 years of industry experience, this discussion addresses contamination and risks prevention, regulatory compliance, and research trends around orphan well integrity.

As part of its series covering orphan wells, AAPG Academy recently hosted a webinar with USDA Research Engineer Dr. Jarrett Wise and petroleum engineer Les Skinner. The conversation shared insights into a sustainable future for orphan well management, touching on contamination prevention, risk mitigation, regulatory compliance and research trends.

The program opened with an overview of orphan well integrity basics led by Skinner.

Key Takeaways from the Discussion led by Les Skinner

Skinner began by defining well integrity as “the properties or conditions of a well that provide containment and prevent the escape of fluids to subterranean formations or surface.” A second definition, he added, would be “the application of technical, operational and organizational solutions to reduce risk of uncontrolled release of formation fluids and well fluids throughout the lifecycle of the well.”

He then covered:

• How well integrity is achieved across the six phases of a well’s lifecycle via barrier elements and barrier envelopes
• The challenges presented by maintaining well integrity in orphan and abandoned wells and why this often leads to leaks

Skinner explained well integrity is important for orphan wells because:

• Well integrity must be sufficient for any work done on the well, including abandonment
• Many orphans have been idle for an extended period of time
• The processes that impact well integrity continue regardless of legal status
• Barriers in orphaned wells must last indefinitely

He ended with a model of how to properly plug an orphaned well.

Key Takeaways from the Discussion Led by Dr. Jarrett Wise

Dr. Jarrett Wise then shared findings from his research on leaking wells. His presentation was broken into three parts, touching on research trends in:

1. Numerical well integrity models used to predict wellbore integrity and factors that cause issues
2. Gas fluid flow models
3. Cement bond strength testing

Section Highlights

Essential conclusions from each section, included:

1. Numerical well integrity models
   • These can predict factors that cause microannuli formation and quantify fracture width
2. Gas fluid flow models
   • Greenhouse gases cannot be modeled assuming Hagen-Poiselle flow
   • The effect of gravity is important on gas flow
3. Cement bonding strength testing
   • Cement to steel bonding acts as a spring up to 0.5mm
   • Strain rate affects measurements

Dive Deeper

AAPG will host an in-person workshop on orphan wells in Pittsburgh, Pennsylvania on the 27–28 of February 2024, to be followed by a Training Course on Methane Measurement on 29 February. Learn more and pre-register here.