دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

the inside annulus;tubing-by-production casing annulus. (Note, there may be regional differences in the A, B, C annulus designations and some are reversed. Inside annuli (IA) and outside annuli (OA) are more universally descriptive.)

n: the amount of moisture present in the air. It may be expressed in milligrams of water per cubic metre of air. Compare relative humidity.

n: a measure of the ability of a single fluid (such as water, gas, or oil) to flow through a rock formation when the formation is totally filled (saturated) with that fluid. The permeability measure of a rock filled with a single fluid is different from the permeability measure of the same rock filled with two or more fluids. Compare effective permeability, relative permeability.

permeability to a single phase fluid in a cleaned core.

n: a chemical additive that reduces the setting time of cement. See cement, cementing materials.

n: A downhole tool used in conjunction with a jar to store energy that is released suddenly when the jar operates.

n: any chemical compound. one element of which is hydrogen, that dissociates in solution to produce free hydrogen ions. For example, hydrochloric acid. HCI, dissociates in water to produce hydrogen ions, H+, and chloride ions, CI-. This reaction is expressed chemically as HCI + H+ + CI- . See ion.

a reactive material with a low pH. Common oilfield mineral acids are HCl and HCl/HF.

n: a naturally occurring clay that, after activation, usually with acid, is used mainly as a decolourant or refining agent, and sometimes as a desulphuriser, coagulant, or catalyst.

v: to part or open fractures in productive hard limestone formations by using a combination of oil and acid or water and acid under high pressure. See formation fracturing.

to fracture stimulate a formation by injecting the acid over the parting pressure of the rock and using the acid to etch channels in the fracture face.

n: the quality of being acid. Relative acid strength of a liquid is measured by pH. A liquid with a pH below 7 is acid. See pH.

n: The relative acid strength of liquids as measured by pH. A pH value below 7. See pH.

n: a record of the measurement of porosity, done by comparing depth to the time it takes for a sonic impulse to travel through a given length of formation. The rate of travel of the sound wave through a rock depends on the composition of the formation and the fluids it contains. Because the type of formation can be ascertained by other logs, and because sonic transit time varies with relative amounts of rock and fluid, porosity can usually be determined in this way.

n: A display of traveltime of acoustic waves versus depth in a well. The term is commonly used as a synonym for a sonic log. Some acoustic logs display velocity.

n: a system consisting of a beacon positioned on the seafloor to transmit an acoustic signal, a set of three or four hydrophones mounted on the hull of a floating offshore drilling vessel to receive the signal, and a position display unit to track the relative positions of the rig and the drill site. Monitoring of the display unit aids in accurate positioning of the rig over the site.