دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: (NH4)2HPO4, white crystalline material. Usually used as mud thinner of drilling fluid and shale inhibiter.

n: the standard unit of gamma ray measurement. Standardisation of this unit results from the normalisation of the detector-measurement systems of all primary service companies in the API test pits at the University of Houston. The API gamma ray unit is defined as 1/200 of the difference in log deflection between two zones of different gamma ray intensity. The test pit is constructed so that the average midcontinent shale will record about 100 API gamma ray units.

adj: pertaining to sand or sandy rocks (such as arenaceous shale).

sand particles, 0.625 to 2 mm on the Udden-Wentworth scale.

adj: pertaining to a formation that consists of clay or shale (such as argillaceous sand).

rocks or substances composed of clay minerals, less than 0.625mm, or having a high proportion of clay in their composition such as shale

n: A kind of invert emulsion mud that the chemical potential of drilling fluid is equal to the chemical potential of water in the drilled formation. The salinit in the water phase is usually equal to salinit in the shale water. It can prevent shale permeatin

n: a reef or mound built by small organisms and their remains, such as coral, plankton, and oysters. Originally a waveresistant coral structure served as an anchor for calcareous debris that formed limestone. It was tectonically submerged, or the sea level rose faster than the corals could build it, and it was eventually buried beneath marine shales. A bioherm is often porous enough to hold large accumulations of hydrocarbons, especially if it has been dolomitized. A bioherm is a stratigraphic trap.

n: see oil shale.

an in determinant term generally meaning a shale with a higher organic content than a brown or gray shale.

n: jamming or wedging of the drill string in the borehole by sand or shale that is driven uphole by formation fluids during a blowout.

n: an effect that occurs when certain shale zones are penetrated by the wellbore and the pressure exerted by the drilling mud exceeds the pressure exerted by the shale. The pressure differential causes the borehole to flex, or balloon, and the borehole no longer behaves as a fixed, rigid cylinder.