scope:

This document, prepared by the API Underground injection Control Issue Group (UICIG), provides guidance on environmentally-sound abandonment practices for wellbores drilled for oil and gas exploration and production (E&P) operations. The guidance is focused primarily on onshore wells. Guidance is provided for the practices that may be used and for the selection and placement of materials necessary to accomplish the following:

• Permanently abandon wells.

• Place wells on inactive status.

Permanent abandonment should be performed when there is no further utility for a wellbore by sealing the wellbore against fluid migration. Inactive well practices may be performed when a wellbore has future utility, such as for enhanced oil recovery projects. This permits the operator to hold the well in a condition that facilitates restoring its utility.

The purpose of this document is to address the environmental concerns related to well abandonment and inactive well practices. The primary environmental concerns are protection of freshwater aquifers from fluid migration, as well as isolation of hydrocarbon production and water injection intervals. Additional issues discussed herein are protection of surface soils and surface waters, future land use, and permanent documentation of plugged and abandoned (P&A) wellbore locations and conditions.

The guidance contained in this document is presented by the following process:

1. Discussing a methodology for assessing the contamination potential of wells.

2. Describing the environmental concerns that justify proper wellbore abandonment procedures.

3. Describing permanent plugging and abandonment procedures.

4. Establishing risk based guidelines for monitoring inactive wells.

5. Summarizing major environmental legislation and associated regulations applicable to wellbore abandonments.

API encourages use of well abandonment practices based on the methods presented in this document. API also supports any Federal and state well abandonment programs consistent with its guidance. There are numerous Federal and state statutes, rules, and regulations specifying proper well abandonment practices. Users of this document should review the current requirements of Federal, state, and local regulations to ensure that this guidance is consistent with those regulatory requirements.