20 October 2021

Annulus friction pressure (AFP)

Difference between bottomhole pressure (BHP) and choke pressure due to friction; a function of flow rate, hole geometry, surface roughness, fluid properties.
18 July 2017

Anticline

An arched, inverted-trough configuration of folded rock layers. Compare Syncline.
25 July 2017

API gravity

The measure of the density of gravity of liquid petroleum products in the United States; derived from relative density in accordance with the following equation: API […]
25 July 2017

Assistant driller’s chair

See Driller’s chair.