CCUS Well Integrity: Why Ranging Belongs in Your MRV Plan

A carbon-storage site is only as secure as its leakiest well. Storage complexes are often co-located with old oil and gas fields full of legacy wells, and any one of them can become a leakage pathway. Magnetic ranging is how you find, seal and verify them.

The legacy-well problem

Permanent CO₂ storage demands absolute zonal isolation. But the depleted reservoirs that make good storage sites are frequently riddled with decades-old wells, many poorly documented, some entirely unrecorded, and a number with degraded integrity. Each is a potential conduit for stored CO₂ to migrate.

Regulators know this. To permit a storage site, an operator must demonstrate that every well is located, sealed and monitorable. Conventional methods struggle when wells are lost or inaccessible from surface.

Find every well

Magnetic ranging locates and intercepts legacy and injection wells with inch-level accuracy, including wells that cannot be accessed from surface. Passive ranging can even help locate undocumented 'ghost' wells from existing survey data.

Seal it, then prove it

Once located, a relief-style intercept lets Gunnar place a permanent plug inside a target well that has no usable surface access, converting a potential leakage path into verified isolation. The same precision supports accurate placement of CO₂ injection and monitoring wells.

Crucially, ranging produces distance-and-direction data that documents exactly where each well is and that it has been sealed. That evidence feeds directly into a monitoring, reporting and verification (MRV) plan, underpinning a credible storage permit.

Designed for the carbon economy

Gunnar has presented this approach at industry forums including the DEA and in Stavanger, Norway, framing magnetic ranging as a pivotal tool for sealing the most challenging wells and enabling efficient, durable CO₂ sequestration in depleted reservoirs.