Well plugging and abandonment is one of the more technically specific obligations in the oil and gas regulatory framework and one where the consequences of inadequate execution follow a property and its owners for decades after the work is nominally complete. A well that is not properly abandoned in accordance with the regulatory requirements of the applicable jurisdiction creates ongoing liability that does not diminish with time, and that eventually presents itself as a remediation problem that is more expensive than the original abandonment would have been.

Well plugging done properly eliminates that future liability and satisfies the regulatory closure requirements that allow a site to be released from the obligations associated with the well's operational history.

What proper abandonment involves

The plugging programme for an abandoned well needs to address the zones within the wellbore that require isolation to prevent fluid migration between formations or to the surface. The specific plugging requirements are determined by the regulatory authority and by the wellbore conditions, including the casing configuration, the formation pressures, and the fluids present in the wellbore.

Cement plugs placed at the appropriate depths and verified to have achieved the required bond provide the mechanical isolation that prevents the cross-formation communication that abandonment is designed to prevent. The placement method, the cement formulation, and the verification of plug quality all affect whether the abandonment achieves the isolation it is required to provide.

Surface casing and regulatory closure

The surface casing cut and cap requirements for abandoned wells address the above-ground presence of the well in a way that satisfies both the regulatory closure requirements and the practical site restoration objectives of the landowner or operator. The cut is made at the required depth below grade, the casing is sealed, and the surface is restored to allow the land to be returned to its pre-well use.

Documentation of the abandonment programme, the materials used, and the verification results is the record that demonstrates regulatory compliance and that provides the evidence required to obtain the abandonment approval that releases the regulatory obligations associated with the well.

Pipeline and road cross abandonment

The abandonment of pipelines crossing beneath roads and other infrastructure involves the specific regulatory requirements applicable to those crossings alongside the technical execution of the abandonment programme.

At Nuwave Industries, well-plugging and abandonment services are delivered with the regulatory knowledge and technical execution capability that closure programmes require to achieve genuine release of the obligations they are designed to address.

The closure that actually closes

Well abandonment that satisfies the regulatory requirements and eliminates future liability is the only version of this work that achieves what the obligation demands.

This article’s author is John Ruskin. For additional information regarding Well Plugging and Abandonment please continue browsing our website at nuwaveindustries.com.