دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a special coupling device inserted one or two joints above the bottom of the casing string that contains a check valve to permit fluid to pass downward but not upward through the casing. The float collar prevents drilling mud from entering the casing while it is being lowered, allowing die casing to float during its descent and thus decreasing die load on die derrick or mast.

n: a special device inserted one or two jionts above the bottome of a casing string,the float collar contains a check valve that permits fluid flow in a downward direction only,the collar thus prevents the back-flow of cement once it has been displaced.

a short piece of casing run one to two joints above the end of casing. The collar contains a backpressure or check valve which stops cement from reentering the well after displacement into the annulus. It is useful to prevent channels in the cement until

n: a short. heavy, cylindrical steel section with a rounded bottom that is attached to the bottom of the casing string. It contains a check valve and functions similarly to the float collar but also serves as a guide shoe for the casing.

n: a short cyclindrical steel component that is attached to the bottom of a casing string,the float shoe has a check valve and functions in the same manner as the float collar,in addition,the float shoe has a rounded bottom that acts as a guide shoe for the

same function as a float collar but run on the end of the casing.

n: a check valve that prevents upward flow through the drill string.

n: a switch in a circuit that is opened or closed by the action of a float and that maintains a predetermined level of liquid in a vessel.

n: see drill pipe float.

n: refer to”drill pipe flot“

the primary, bottom hole valve in the float collar or shoe that allow the casing to self fill while running and allows the cement to pass into the annulus but helps prevent cementing U-tubing after the job. Drillable and subject to erosion wear.

n: a lightweight covering of either metal or plastic material designed to float on the surface of the liquid in a tank. Alternatively, it may be supported by a float system so that it is just above the free liquid surface. Used to minimise the evaporation of volatile products in a tank.

n: a tank covering that rests on the surface of a hydrocarbon liquid in the tank and rises and falls with the liquid level. A floating roof eliminates vapour space above the liquid in the tank and conserves light fractions of the liquid.

n: the rate 0f the air flow which prevents the cuttings dropping and upgoing during air dirlling