دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a nonionic polymer (polyacrylamide) used in flocculation, clarifying and even gelling acids and other brines. Very stable, but difficult to effectively break.

n: the adhesion of a thin film of a gas or liquid to the surface of a solid. Liquid hydrocarbons are recovered from natural gas by passing the gas through activated charcoal, silica gel, or other solids, which extract the heavier hydrocarbons. Steam treatment of the solid removes the adsorbed hydrocarbons, which are then collected and re-condensed. The adsorption process is also used to remove water vapour from air or natural gas. Compare absorption.

n: A surface phenomenon exhibited by a solid (adsorbent) to hold or concentrate gases, liquids or dissolved substances(adsorptive) upon its surface, due to adhesion.

the attraction and holding of a layer of a chemical on the wall of a formation. Usually held by ionic charge or wetting preference.

n: finely crystalline, generally lightcoloured extrusive igneous rock com- posed largely of plagioclase feldspar with smaller amounts of dark-coloured minerals. Compare diorite.

n: sandstone composed largely of feldspar grains and deriving from granitic source rocks.

A sandstone containing 25% or more of feldspar, usually derived from igneous rock.

a clay-based drilling mud gelling agent.

n: a colloidal clay, composed primarily of montmorillonite, that swells when wet. Because of its gel-forming properties, bentonite is a major component of waterbase drilling muds. See gel, mud.

a reference to colloidal clay (generally montmorillinite or smectite),generates plastic viscosity due to clay behavior, size and electrostatic layer. A slurry of which used for P&A Purposes will weigh no less than 9 ppg.

a crosslinker for guar based gels.

n: see starting torque. break circulation v: to start the mud pump for restoring circulation of the mud column. Because the stagnant drilling fluid has thickened or gelled during the period of no circulation, high pump pressure is usually required to break circulation.

n: a surface wave that has become too steep to be stable.

a chemical added to a gel that breaks down the gellant structure.

n: a conglomerate rock composed largely of angular fragments greater than 0.08 inch (2 millimetres) in diameter.

fragmented (not wear rounded) grains. Rock along moving faults may have this texture.