System and method for a low drag flotation system
View Patent ↗A low drag flotation system for placing screens in horizontal wells is provided which includes a screen exterior to the washpipe to be placed for sand control, and hydraulically actuated valves for trapping air within the washpipe. The air in the washpipe creates a buoyancy force that decreases the drag force of the pipe string in the horizontal well, allowing it to move further down the well under its own weight. As a result, screens can be placed in longer lengths of horizontal wells to maximize oil and gas production.
1. A flotation system for reducing drag forces associated with installing a screen assembly in a well, the flotation system comprising:
a service tool connected to a workstring that extends to a surface; and
a washpipe assembly positioned inside the screen assembly and connected to the service tool, the washpipe assembly comprising:
a washpipe; and
a first valve placed within the washpipe, the first valve being adapted to trap gas within the washpipe, thereby causing the screen assembly to at least partially float within the well, wherein the first valve is proximate an upper end of the washpipe and the system further comprises a second valve proximate a lower end of the washpipe.
2. A system as defined in claim 1 , wherein the first and second valves are hydraulic valves which can be moved to an open and closed position.
3. A method for reducing drag forces associated with installing a screen assembly in a well, the method comprising the steps of:
(a) placing a washpipe assembly inside the screen assembly, the washpipe assembly comprising at least one valve adapted to trap gas inside the washpipe assembly;
(b) trapping gas inside the washpipe assembly;
(c) running the washpipe and screen assemblies into the well;
(d) at least partially floating the screen assembly within the well using the trapped gas
(e) setting the screen assembly at a desired location within the well;
(f) releasing the gas inside the washpipe assembly and circulating the air out of the washpipe assembly; and
(g) retrieving the washpipe assembly from the well.
4. A method as defined in claim 3 , wherein the gas is trapped at a surface location.
5. A method as defined in claim 3 , wherein step (g) further comprises the step of performing a sand control treatment before retrieving the washpipe assembly from the well.
6. A method as defined in claim 3 , wherein the trapped air inside the washpipe assembly is released by increasing a differential pressure against the at least one valve, thereby causing the at least one valve to be actuated in an open position.
7. A method to at least partially float a screen assembly within a well, the method comprising the steps of:
(a) running the screen assembly into the well, the screen assembly comprising a washpipe assembly having gas trapped therein, one or more valves being utilized to trap the gas, the one or more valves configured to move to an open or closed position;
(b) at least partially floating the screen assembly within the well using the trapped gas;
(c) setting the screen assembly at a desired location within the well; and
(d) actuating the one or more valves into an opened position, thereby releasing the trapped gas, and circulating the trapped gas out of the well.