Fundamental to all electronic gas measurement (EGM) and electronic liquids measurement (ELM) systems is the ability to accurately measure, review, correct, and report data. Any weakness in this chain undermines the accuracy and data integrity in the system.
Recent industry standards and practices have greatly expanded the emphasis on data integrity. The SarbanesOxley (SOX) Act of 2002 focuses on the integrity and consistency of all financial-based transactions for an organization.
A SOX auditor will directly reference the American Petroleum Institute (API) Manual of Petroleum Measurement Standards (MPMS) Chapter 21 (popularly known as “API 21”) as the standard for all steps in the measurement process throughout an organization. Therefore, measurement personnel must possess a thorough understanding of API 21 and put its requirements to practice in order to satisfy the audit process.
Natural gas operations must comply with API MPMS Chapter 21, Section 1 (“API 21.1”), Flow Measurement Using Electronic Metering Systems—Electronic Gas Measurement. A second edition, published in 2013, includes substantial revisions to the original, 1993 edition.
Over recent years, a number of companies in the industry have acquired natural gas and petroleum liquids operations. Measurement departments tracking both natural gas and liquids must comply with API 21.2 as well as API 21.1.
API MPMS Chapter 21, Section 2, Electronic Liquid Volume Measurement Using Positive Displacement and Turbine Meters, was released in 1998. An addendum, Flow Measurement Using Electronic Metering Systems, Inferred Mass, followed in 2000.