Updated API Standard Improves Measurement of Annular Casing Pressure at Offshore Wells

The American Petroleum Institute (API) recently updated its safety standard for measuring annular casing pressure at offshore energy facilities, publishing the 2^nd Edition of Recommended Practice (RP) 90-1, Annular Casing Pressure Management for Offshore Wells.

The 2^nd edition was developed with input from key industry stakeholders including representatives from the U.S. federal government’s Bureau of Safety and Environmental Enforcement (BSEE), international natural gas and petroleum companies and other subject matter experts. The new edition builds upon the first, which is incorporated by reference in U.S. federal regulations (30CFR Part 250.519) and incorporates updated safety information to reduce risk to personnel and the environment

RP 90-1 recognizes the importance of managing annular casing pressure (ACP), an integral part of maintaining safe and environmentally sustainable offshore well operations on the outer continental shelf (OCS) and across the globe. To this end, the document provides important guidelines for operating offshore wells with ACP, such as those with thermally induced casing pressure, sustained casing pressure, and operator-imposed pressure.

The 2^nd Edition seeks to improve upon the monitoring and diagnostic testing for assessing the maximum allowable pressure (MAWOP) at the annulus, the space that separates a well’s piping from the well casing. The standard provides recommendations for calculation of MAWOP using the simple derating method (SDM) and explicit derating method (EDM) to allow for a more accurate assessment of the actual MAWOP, in addition to preservation of the default deration method (DDM).

Another key change includes providing guidelines for the upper and lower diagnostic threshold (DT) selection, which allows testing, increased monitoring and other measures to be initiated prior to the annular pressure reaching the MAWOP. Expanded documentation measures were added along with improved risk assessment methodology.

The new methodologies introduced in RP 90-1, 2^nd Edition, improve MAWOP and ACP risk assessment at all offshore wells, including fixed platform wells, subsea wells, hybrid wells and mudline suspension wells. The guidelines provided help enhance overall safety for offshore operators, their crews, host communities and the marine environments where these facilities operate.

As new technologies and methodologies are developed within the industry, API strives to incorporate these enhancements into standards. The natural gas and oil industry and API continue to drive innovation by developing new technology and approaches to meet global demand for affordable, reliable and cleaner energy while maintaining safe and responsible operations.

These updates and the other guidelines included in the RP help reduce potential greenhouse gas (GHG) emissions from a pressured annulus in an offshore well, supporting the United Nations Sustainable Development Goal on Climate Action (SDG 13). Additionally, the RP further allows the operator to begin diagnostics to identify potential issues in advance of the pressure reaching the maximum value. Both prevent fugitive emissions from the well into the environment.

For more information on RP 90-1, 2^nd Edition, and API’s more than 700 world-class standards developed to drive safety, operational performance improvements and sustainability, visit www.api.org/products-and-services/standards.