Casing string

Casing string

Casing string is a long section of connected oilfield pipe that is lowered into a wellbore and cemented. The pipe joints are typically about 40 ft [12 m] in length, male threaded on each end and connected with short lengths of double-female threaded pipe called couplings.

Casing is run to protect or isolate formations adjacent to the wellbore. It is generally not possible to drill a well through all of the formations from surface (or the seabed) to the target depth in one hole section. The well is therefore drilled in sections, with each section of the well being sealed off by lining the inside of the borehole with steel pipe, known as casing and filling the annular space between this casing string and the borehole with cement, before drilling the subsequent hole section. This casing string is made up of joints of pipe, of approximately 40ft (12m) in length, with threaded connections. Depending on the conditions encountered, three or four casing strings may be required to reach the target depth. The cost of the casing can therefore constitute 20-30% of the total cost of the well. Great care must therefore be taken when designing a casing programme which will meet the requirements of the well.


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См. также в других словарях:

  • Casing (borehole) — Casing is large diameter pipe that is assembled and inserted into a recently drilled section of a borehole and typically cemented into place.PurposeCasing that is cemented in place aids the drilling process in several ways: * Prevent… …   Wikipedia

  • Casing hanger — The casing hanger is that portion of a wellhead assembly which provides support for the casing string when it is lowered into the wellbore. It serves to ensure that the casing is properly located. When the casing string has been run into the… …   Wikipedia

  • Casing shoe — In oil drilling and borehole mining, a casing shoe or guide shoe is a bull nose shaped device which is attached to the bottom of the casing string. A casing hanger, which allows the casing to be suspended from the wellhead, is attached to the top …   Wikipedia

  • casing shoe — noun In drilling, a bull nose shaped device, known as a guide shoe or casing shoe, is attached to the bottom of the casing string and a casing hanger, which allows the casing to be suspended from the wellhead, is attached to the top of the casing …   Wiktionary

  • casing — noun a) That which encloses or encases. Some people like to split the casing of a sausage before cooking so it doesnt split, others dont. b) The collective states of upper and lower case letters. The replacement string should have the same casing …   Wiktionary

  • casing shoe — noun : a cylinder or ring of hard steel with a cutting edge attached to the bottom of a string of well casing …   Useful english dictionary

  • casing — noun Date: 1791 1. something that encases ; material for encasing: as a. an enclosing frame especially around a door or window opening b. a metal pipe used to case a well c. tire IV,2 d. a membranous case for processed meat …   New Collegiate Dictionary

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  • draw-string — drawˈ string or drawˈstring noun A string or cord, etc, in a casing in or threaded through material, by which the material may be drawn or gathered up adjective Having or closed by such a string • • • Main Entry: ↑draw …   Useful english dictionary

  • Production string — The production string is a part of an oil well that is composed of the production tubing and other completion components and serves as the conduit through which the production fluid flows from the oil reservoir to the surface through the wellhead …   Wikipedia


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