API RP 90

Description

This Recommended Practice is intended to serve as a guide for managing annular casing pressure in offshore wells. Although the prevention of annular casing pressure is very important, it is beyond the scope of this document. Prevention of annular casing pressure is planned to be addressed in API RP 65, Part 2. The remediation of wells because of sustained casing pressure is also beyond the scope of this document and is planned to be included in API RP 65, Part 3. This guide is meant to be used for offshore wells that exhibit annular casing pressure, including thermal casing pressure, sustained casing pressure (SCP) and operator imposed pressure.

This Recommended Practice covers monitoring, diagnostic testing, the establishment of a maximum allowable wellhead operating pressure (MAWOP) and documentation of annular casing pressure for the various types of wells that occur offshore. Included also is a discussion of risk assessment methodologies that can be used for the evaluation of individual well situations where the annular casing pressure is not within the MAWOP guidelines.