Claims
- 1. A method for controlling a rotary blowout preventer having a first fluid circuit and a second fluid circuit independent from the first fluid circuit mounted over a well bore, comprising the steps of:
introducing a first fluid into the first fluid circuit at a pressure greater than a pressure of the well bore; introducing a second fluid into the second fluid circuit at a pressure less than the pressure of the first fluid; monitoring the pressure of the first fluid; and adjusting the pressure of the second fluid in response to the pressure of the first fluid.
- 2. The method according to claim 1 further including the step of adjusting the pressure of the first fluid in response to the pressure of the well bore.
- 3. The method according to claim 1 further including the step of monitoring the pressure of the second fluid.
- 4. The method according to claim 3 further including the step of predicting a condition of excessive wear in a seal for the second circuit in response to said monitoring step.
- 5. The method according to claim 1 wherein said adjusting step includes determining an adjusted pressure of the second fluid as a percentage of the pressure of the first fluid.
- 6. The method according to claim 1, further including the step of controlling the pressure of the second fluid by adjusting an orifice connected to an outlet of the second fluid circuit.
- 7. The method according to claim 1 wherein the first fluid is introduced into the first fluid circuit at a pressure above the pressure of the well bore sufficient to exert closure.
- 8. A rotary blowout preventer having a stationary body and a rotating body within the stationary body, the rotating body including a packer assembly mounted within the stationary body, comprising:
a first fluid circuit defined into and out of the stationary body and between the stationary body and the rotating body; a second fluid circuit defined into and out of the stationary body and between the stationary body and the rotating body; and a pressure control device for controlling the pressure of a fluid in the second fluid circuit in response to the pressure of a fluid in the first fluid circuit.
- 9. The apparatus according to claim 8, further comprising:
an upper bearing and a lower bearing mounted between the stationary body and the rotating body; and a first seal and a second seal mounted between the stationary body and the rotating body respectively below and above the lower bearing and the upper bearing wherein the first fluid circuit is defined into and out of the stationary body and between the stationary body, the rotating body, the first seal and the second seal; and a third seal mounted between the stationary body and the rotating body above the second seal wherein the second fluid circuit is defined into and out of the stationary body, the rotating body, the second seal and the third seal.
- 10. The apparatus according to claim 9 further including another pressure control device for controlling the pressure of the fluid in the first fluid circuit.
- 11. A rotary blowout preventer having a stationary body, a rotating body including a packer assembly mounted within the rotating body, an upper bearing and a lower bearing mounted between the stationary body and the rotating body, a first seal and a second seal mounted between the stationary body and the rotating body respectively below and above the lower bearing and the upper bearing wherein a first fluid circuit is defined into and out of the stationary body and between the stationary body, the rotating body, the first seal and the second seal, comprising:
a third seal mounted between the stationary body and the rotating body above the second seal wherein a second fluid circuit, is defined into and out of the stationary body and between the stationary body, the rotating body, the second seal and the third seal.
- 12. The apparatus according to claim 11, further comprising:
a pump connected by a first conduit to the stationary body into the second fluid circuit; and an adjustable orifice connected by a second conduit to the stationary body out of the second fluid circuit.
- 13. The apparatus according to claim 12, further comprising:
a second pump connected by a third conduit to the stationary body into the first fluid circuit; and a second adjustable orifice connected by a fourth conduit to the stationary body out of the first fluid circuit.
- 14. The apparatus according to claim 11, further including a carrier bearing mounted in a seal carrier between the stationary body and the rotating body and in a flow line defined by the seal carrier.
- 15. The rotary blowout preventer according to claim 11, wherein the rotating body has a packer sleeve mounted within the packer assembly and the stationary body has a top closure connectable to the stationary body, further including:
a thrust bearing having a lower end and an upper end, the lower end connected to a top end of the packer sleeve and the upper end connected to the top closure.
- 16. A rotary blowout preventer having a stationary body having a top closure connectable to the stationary body, a rotating body including a packer assembly having a packer sleeve mounted within the rotating body, an upper bearing and a lower bearing mounted between the stationary body and the rotating body, a first seal and a second seal mounted between the stationary body and the rotating body respectively below and above the lower bearing and the upper bearing wherein a first fluid circuit is defined into and out of the stationary body and between the stationary body, the rotating body, the first seal and the second seal, comprising:
a thrust bearing having a lower end and an upper end, the lower end connected to a top end of the packer sleeve and the upper end connected to the top closure.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. Utility patent application Ser. No. 09/735,385, filed Dec. 12, 2000 (U.S. Pat. No. 6,554,016) and claims the benefit of same.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09735385 |
Dec 2000 |
US |
Child |
10423105 |
Apr 2003 |
US |