دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: pressure exceeding or falling below the pressure to be expected at a given depth. Normal pressure increases approximately 0.465 pow1ds per square inch per foot of depth or 10.5 kilopascals per metre of depth. Thus, normal pressure at 1,000 feet is 465 pounds per square inch;at 1,000 metres it is 10,500 kilopascals. See pressure gradient.

n: A formation pressure that deviates from the normal formation fluid hydrostatic pressure. Such pressure may be classified as "subnormal" (lower than normal) or "overpressured" (higher than normal).

n: The abnormal pressure per meter in depth, usually express as MPa/m. It is the reference
of density of the mud and the procedure of the casing design.

n: in the abnormal pressure layer,the framework stress of the rock is lower than the framework stress in nomal pressure layer with the same depth ,the lower stress is equal to corresponding stress in some depth,and this depth is called equivalent depth