دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

a build-up of particles on the upstream side of a filter that improves the filter’s ability to remove particles from fluid (will also raise the differential pressure across the filter).

a permeable core from which hydrocarbon escapes without differential pressure application.

n: the holding of formation rock chips in place as a result of high differential pressure in the wellbore (i.e., pressure in the wellbore is greater than pressure in the formation). This effective- its the cutting action of the bit by retarding circulation of bit cuttings out of the hole.

n: (Pl. darcys) a unit of measure of permeability. A porous medium has a permeability of 1 darcy when differential pressure of 1 atmosphere across a sample 1 centimetre long and I square centimetre in cross section will force a liquid of 1 centipoise of viscosity through the sample at the rate of 1 cubic centimetre per second. The permeability of reservoir rocks is usually so low that it is measured in millidarcys.

n: A unit of permeability. A porous medium has a permeability of 1 darcy when a pressure of 1 atm on a sample 1 cm long and 1 sq cm in cross section will force a liquid of 1 cP viscosity through the sample at the rate of 1 cc per sec.

a measurement of permeability (ability of fluids to flow through the rock). The relationship is an empirical law which states that the velocity of flow through porous media is directly proportional to the hydraulic gradient, assuming that the flow is lami

n: see differential pressure.

n: on a flow recorder, the pen used to record differential pressure across the orifice in the meter;usually recorded in red ink on the flow recorder chart.

n: the difference between two fluid pressures;for example, the difference between the pressure in a reservoir and in a well bore drilled in the reservoir, or between atmospheric pressure at sea level and at 10,000 feet (3,048 metres). Also called pressure differential.

n: Pressure difference between two pionts in a system

the difference in pressure between upstream and downstream of a measurement point.

n: Sticking that occurs when a portion of the drill string (usually the drill collars) becomes embedded in the filter cake resulting in a nonuniform distribution of pressure around the circumference of the pipe. The conditions essential for sticking require