WorldWide Drilling Resource

Be Sure To Join Us Once Again at the Sheraton Hotel & Conference Center, Red Deer, AB, Canada April 25 - 27, 2019 Technical Sessions Entertainment Regulations and Information • Annual Meeting Drilling Rigs and New Technology Displays Alberta Water Well Drilling Association Convention and Trade Show For More Information Contact the AWWDA Phone: (780) 386-2335 • E-mail: awwda@xplornet.com 42 APRIL 2019 WorldWide Drilling Resource ® Frequently-Used Geological Terms Part 80 Glossary Adapted from the Dictionary of Geological Terms R Relative Age - The geologic age of a fossil, rock, geologic feature, or event defined relative to other fossils, rocks, features, or events rather than in terms of years. Relative Dating - The chronological ordering of features, fossils, or events with respect to the geologic time scale without ref- erence to their absolute age. Relict Texture - In mineral deposits, an original texture which remains after partial or total replacement. Remanent Magnetization - The component of a rock’s magnetization which has a fixed direction relative to the rock and is independent of moderate, applied magnetic fields such as the earth’s magnetic field. Reniform - Kidney shaped. Said of a crystal structure in which radiating crystals terminate in rounded masses. Also used to describe mineral deposits with a surface of rounded, kidney-like shapes. Reserves - Identified resources of mineral- or fuel-bearing rock from which the mineral or fuel can be extracted profitably with existing technology and under present economic conditions. The concept can be used in global, regional, or local senses, or applied as a measure of the remaining effective life of an individual mine. Reservoir - A subsurface volume of porous and permeable rock in which gas or oil has accumulated. Also used to describe a subsurface rock or regolith which is satu- rated with water; an aquifer. Reservoir Gas-Oil Ratio - The number of cubic feet of gas per barrel of oil in the reservoir. Reservoir Pressure - Bottom hole pressure. Reservoir Rock - Any porous and permeable rock which yields gas or oil. Sandstone, limestone, and dolomite are the most common types. Residual Clay - Clay material formed in place by the weathering of rock, derived either from the chemical decay of feldspar and other rock minerals or from the removal of nonclay-mineral, constituents by solution from a clay-bearing rock such as argillaceous limestone. Look for more terms next month! WWDR photo of the Marianna Limestone Mine in Marianna, Florida. G&O