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grad(P) = pressure gradient = 8.33 / 19.25 = 0.43273 psi/ft. and the hydrostatic bottom hole pressure (BHP) is then BHP = TVD * grad(P) = 21,000 * 0.43273 = 9,087 psi. However, the formation fluid pressure (pore pressure) is usually much greater than a column of fresh water, and can be as much as 19 lb/U.S. gal (e.g., in Iran). For an onshore ...
The horizontal pressure gradient is a two-dimensional vector resulting from the projection of the pressure gradient onto a local horizontal plane. Near the Earth's surface, this horizontal pressure gradient force is directed from higher toward lower pressure. Its particular orientation at any one time and place depends strongly on the weather ...
Subnormal pore pressure is defined as any formation pressure that is less than the corresponding fluid hydrostatic pressure at a given depth. [6] Subnormally pressured formations have pressure gradients lower than fresh water or less than 0.433 psi/ft (0.0979 bar/m).
Under formation pressure, there are 3 levels: normally pressured formation, abnormal formation pressure, or subnormal formation pressure. Normally pressured formation As the fluids above the formation are usually some form of water, this pressure can be defined as the pressure exerted by a column of water from the formation's depth to sea level.
Flux F through a surface, dS is the differential vector area element, n is the unit normal to the surface. Left: No flux passes in the surface, the maximum amount flows normal to the surface. Right: The reduction in flux passing through a surface can be visualized by reduction in F or dS equivalently (resolved into components, θ is angle to ...
The Corrected d-exponent, also known as dc-exponent or cd-exponent, is a parameter used in mud logging and formation pore pressure analysis in the petroleum industry. It is an extrapolation of certain drilling parameters to estimate a pressure gradient for pore pressure evaluation while drilling, particularly in over-pressured zones.
In fluid mechanics, the pressure-gradient force is the force that results when there is a difference in pressure across a surface. In general, a pressure is a force per unit area across a surface. A difference in pressure across a surface then implies a difference in force, which can result in an acceleration according to Newton's second law of ...
The second equation expresses that, in the case the streamline is curved, there should exist a pressure gradient normal to the streamline because the centripetal acceleration of the fluid parcel is only generated by the normal pressure gradient. The third equation expresses that pressure is constant along the binormal axis.