دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

particles propelled at a velocity sufficient to cause cleaning or wearing away of a surface.

n: the force in dynes that a stationary flat plate with a surface area of 1 square centimetre exerts on a similar parallel plate 1 centimetre away and moving in its own plane with a velocity of 1 centimetre per second, the space between the plates being filled with the liquid in question. It is a measure of the resistance that the liquid offers to shear. absolute error n: the difference between the result of a measurement and the true value of the measured quantity as determined by means of a suitable standard device.

the velocity of an imposed sound wave (acoustic velocity) through a rock times the density of the rock.

n: a record of the measurement of porosity, done by comparing depth to the time it takes for a sonic impulse to travel through a given length of formation. The rate of travel of the sound wave through a rock depends on the composition of the formation and the fluids it contains. Because the type of formation can be ascertained by other logs, and because sonic transit time varies with relative amounts of rock and fluid, porosity can usually be determined in this way.

n: A display of traveltime of acoustic waves versus depth in a well. The term is commonly used as a synonym for a sonic log. Some acoustic logs display velocity.

velocity of an imposed sound wave through a rock.

n: a roller cone bit that is specially designed for air or gas drilling. It is very similar to a regular bit, but features screens over the bearings to protect them from clogging with cuttings and thicker hardfacing on the shirttail to protect them from abrasive, high-velocity air or gas drilling fluid.

n: a large, sloping sedimentary deposit at the mouth of a canyon, laid down by intermittently flowing water, especially in arid climates, and composed of gravel and sand. The deposit tends to be coarse and unworked, with angular, poorly sorted grains in thin, overlapping sheets. A line of fans may eventually coalesce into an apron that grows broader and higher as the slopes above are eroded away.

land counterpart of a river delta. Characteristic of sediments that have been transported by a fast moving stream then dropped out of the flow as the stream velocity drops as it spreads out. Typical of zones of heavy water runoff such as found at the base

n: a measure of the time required for a flowing medium. such as a fluid. to change its angular displacement.

n: The return velocity of the drilling fluid in the annular.