DRILLBITS
Monthly eNewsletter from the IADC




IADC Lexicon Featured Term for May 2025

The IADC Lexicon is an oil and gas dictionary of upstream-related terms, which, unlike conventional glossaries, are official definitions drawn from legislation, regulation and regulatory guidance, standards (global, national and regional), IADC guidelines, and Well Control Institute. Terms often have multiple definitions from different sources.

This month’s featured term is:

Return Flow Control

MPD technique which diverts returned fluid flow away from the rig floor in order to handle any formation fluid influx, thereby avoiding closing of a BOP, with the subsequent well control steps that are customarily required. RFC is drilling with a closed annulus return system (RCD) immediately under the rig floor for complete assurance of the total diversion of any rapidly developing kick.

Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global Standards