دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a relatively impermeable stratum that does not transmit water fast enough to supply a well.

n: An impermeable layer of rock overlying an oil or gas reservoir and preventing the migration of fluids.

a sealing formation of very low permeability that forms the top or the seal in a reservoir.

n: 1. a disklike plate of anhydrite, gypsum, limestone, or sulphur overlying most salt domes in the Gulf Coast region. 2. impermeable rock overlying an oil or gas reservoir that tends to prevent migration of oil or gas out of the reservoir.

n: the location of the bottom of a string of casing that is cemented in a well. Typically, a casing shoe is made up on the end of the casing at this point.

n: The position of the bottom of casing string after cementing.

the set point of the end of casing. Should be in an impermeable, stable formation.

n: a condition in which the drill stem becomes stuck against the wall of the wellbore because part of the drill stem (usually the drill collars) has become embedded in the filter cake. Necessary conditions for differential-pressure sticking, or wall sticking, are a permeable formation and a pressure differential across a nearly impermeable filter cake and drill stem. Also called wall sticking. See differential pressure, filter cake.

n: One of the mechanisms causing stuck pipe by having excessive mud weight.

a common method of pipe sticking where the overbalance pressure in the wellbore pushes the tubing against the side of the wellbore in a permeable formation.

n: a subsurface hydrocarbon trap created by faulting, in which an impermeable rock layer has moved opposite die reservoir bed or where impermeable gouge has sealed the fault and stopped fluid migration.

a formation that contains oil or gas that is held in place by a displaced, non permeable rock mass.

n pi: impermeable shales, highly compressed by overburden pressure, that are characterized by large amounts of formation fluids and abnormally high pore pressure.

n: 1. a subsurface layer of rock containing steam or hot water that is trapped in the layer by overlying impermeable rock. 2. a subsurface layer of rock that is hot but contains little or no water. Geothermal reservoirs are a potential source of energy.

adj: preventing the passage of fluid. A formation may be porous yet impermeable if there is an absence of connecting passages between the voids within it. See permeability.

adj: preventing the passage of the fluid through the pores of the rock.

Rock with passages so small that no effective flow can take place. Note: all manmade and natural substances have some permeability, given high pressure, time, enough surface area and a low permeability fluid.