Circulating cementing collar and method
AssigneeHalliburton Energy Services, Inc.
InventorsDavid D. Szarka, Henry E. Rogers
Life of this patent
Estimating the term…
Abstract
An apparatus and method for cementing a casing string in a wellbore. A self-filling tubular cementing collar connected to the lower end of a casing string is provided with one-way flow valving that allows well fluid to enter and self-fill the casing string as it is lowered into the wellbore and automatically prohibits reverse fluid flow from the collar when washing or cementing during forward circulation through the collar. The one-way valving is carried by an axially movable support that can be shifted by a cementing plug moved by pump pressure to permanently seal the entry flow passage after the casing sting is properly positioned in the wellbore.
Claims39
A cementing collar comprising:
- first one-way flow valving for admitting fluid into the collar through an entry flow passage when the pressure of fluids external to the collar is greater than the pressure of fluids internal to the collar;
- and
- second one-way flow valving for allowing fluid to flow from the collar through an exit flow passage when the pressure of fluid inside the collar is greater than the pressure of fluid outside the collar.
A method of cementing a casing string in a wellbore, comprising:
- lowering a casing string equipped at its lower end with a cementing collar into a wellbore containing drilling fluids;
- flowing drilling fluids from said wellbore into said casing string through a first one-way valve in said cementing collar, said first one-way valve permitting fluid flow in a direction from said wellbore into said cementing collar through an entry flow passage extending through said cementing collar and preventing fluid flow through said entry flow passage in a direction from said cementing collar into said wellbore;
- pumping drilling fluids from said casing string into said wellbore through an end of said casing while said entry flow passage is closed to fluid flow from said casing string to said wellbore;
- and
- thereafter, flowing drilling fluids from said wellbore into said casing string through said entry flow passage.
A self-fill cementing collar, comprising:
- a tubular collar body having a fill port extending through a wall of said body;
- a tubular valve sleeve carried coaxially internally of said collar body, said tubular valve sleeve being movable axially between first and second axially spaced positions within said tubular collar body;
- a flow passage extending through a wall of said valve sleeve for fluid communication with said fill port in said collar body when said tubular valve sleeve is at said first position;
- a check valve carried by said valve sleeve for admitting or preventing flow of fluid between said fill port and said flow passage when said tubular valve sleeve is at said first position;
- and
- a temporary retainer for securing said tubular valve sleeve at said first position.
Dependencies are inferred from the claim text.