Estimated pore pressure, as used in the

oil industry The petroleum industry, also known as the oil industry or the oil patch, includes the global processes of exploration, extraction, refining, transportation (often by oil tankers and pipelines), and marketing of petroleum products. The larges ...

and

mud logging Mud logging is the creation of a detailed record (well log) of a borehole by examining the cuttings of rock brought to the surface by the circulating drilling medium (most commonly drilling mud). Mud logging is usually performed by a third-part ...

, is an approximation of the amount of force that is being exerted into the

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petro ...

by fluids or gases within the

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

that has been penetrated.http://www.glossary.oilfield.slb.com/Display.cfm?Term=pore%20pressure Schlumberger: Oilfield Glossary In the

, estimated pore pressure is measured in pounds per square inch (psi), but is converted to ''equivalent mud weight'' and measured in pounds per gallon (lb/gal) to more easily determine the amount of mud weight required to prevent the fluid or gas from escaping and causing a blowout or wellbore failure.

References

{{Petroleum-stub Petroleum engineering Oilfield terminology