Capillary Pressure
Curvature at an interface between wetting and nonwetting phases causes a pressure difference that is called capillary pressure. This pressure can be viewed as a force per unit area that…
Wettability and Contact Angle
The contact angle (ec), existing between two fluids in contact with a solid and measured through the more dense phase, is a measure of the relative wetting or spreading by…
Surface and lnterfaclal Tensions
The term interface indicates a boundary or dividing line between two immiscible phases. Types of interfaces include: liquid-gas, liquid-liquid, liquidsolid, solid-gas, and solid-solid. For fluids, molecular interactions at the interface…
Resistivity Index
Since crude oil and natural gas are nonconductors of electricity, their presence in reservoir rock increases resistivity. The resistivity index or ratio, I, is commonly used to characterize reservoir rocks…
Total Reservolr Compressibility
The total compressibility of oil- or gas-bearing reservoirs represents the combined compressibilities of oil, gas, water, and reservoir rock in terms of volumetric weighting of the phase saturations: where c,…
Formation Resistivity Factor
The formation resistivity factor, FR, is the ratio of the resistivity of a porous medium that is completely saturated with an ionic brine solution divided by the resistivity of the…
Properties of Fluid-Containing Rocks
Porosity The porosity, 4, is equal to the void volume of the rock divided by the bulk volume and is expressed as a percent or fraction of the total bulk…
Units and Conversions
We have used “oilfield” units throughout the text, even though this system of units is inherently inconsistent. We chose this system because more petroleum engineers “think” in bbl/day and psi…
Well Productivity and Production Engineering
Many of the components of the petroleum production system can be considered together by graphing the inflow performance relationship (IPR) and the vertical flow performance (VFP). Both the IPR and…
The Surface Equipment
After the fluid reaches the top, it is likely to be directed toward a manifold connecting a number of wells. The reservoir fluid consists of oil, gas (even if the…
