دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: an acidizing treatment in which the acid is placed in the wellbore and allowed to react by merely soaking. It is a relatively slow process, because very little of the acid actually comes in contact with the formation. Also called wellbore cleanup. See matrix acidizing. Compare acidfracture.

the after flow, created by wellbore volume, into a wellbore after the surface valve has been closed.

a solvent or acid wash of the wellbore with minimum leakoff into the matrix.

n: the equipment installed at the surface of the wellbore. A wellhead includes such equipment as the casinghead and tubing head. adj: pertaining to the wellhead (e.g., wellhead pressure).

the mechanical connection between the tree and the casing. May house tubular hangers, annular access valves. It is connected to the casing by welding, threads, hydraulic forming or set screws.

n: The surface termination of a wellbore that incorporates facilities for installing casing hangers during the well construction phase. The wellhead also incorporates a means of hanging the production tubing and installing the Christmas tree and surface flow

n: a long steel casing that uses an inclined plane to cause the bit to deflect from the original borehole at a slight angle. Whipstocks are sometimes used in controlled directional drilling, in straightening crooked boreholes, and in sidetracking to avoid unretrieved fish.

n: A device inserted in a well bore used for deflecting or for directional drilling.

a hardened steel ramp along which a mill turns as it cuts a hole in the side of the casing to start a sidetrack or lateral wellbore.

the allowable effective fluid density difference between the fracturing pressure and the pressures exerted by a fluid that are needed to control formation flow and the wellbore.

n: a flared-end sub run on the end of the tubing string to permit easy access of wireline tools into the tubing ID.

a small fitting on the end of a tubing string that is shaped to allow easier entry of logging tools when pulled back into the tubing from the wellbore below.

A acidic salt, ZnBr2, which is used to prepare dense, clear (solids-free) brine for well completion and workover operations. The density of saturated zinc bromide is approximately 20 lbm/gal, but its pH is low and can cause acidic corrosion and handling p