1. A system for retracting a readwrite head to a landing position of a disk in a disk drive, said system comprising:
an actuator coupled with said readwrite head for retracting said readwrite head in a first direction toward an outside diameter of said disk and a second direction toward an inside diameter of said disk in response to respective signals; and
a control device coupled with said actuator and adapted for determining a retract direction for said readwrite head, wherein a first signal indicative of a first direction and a second signal indicative of a second direction are provided to said actuator, said control device further providing said first signal responsive to a power off condition and providing said second signal subsequent to providing said first signal for retracting said readwrite head to said landing position,
wherein said control device provides said second signal at a predetermined time period following said power off condition,
wherein said control device is further adapted for comparing a predetermined reference voltage with a b-emf voltage produced by the disk drive motor of said disk drive system for producing said second signal following said power off condition.
2. A system for retracting a readwrite head to a landing position of a disk in a disk drive, said system comprising:
an actuator coupled with said readwrite head for retracting said readwrite head in a first direction toward an outside diameter of said disk and a second direction toward an inside diameter of said disk in response to respective signals; and
a control device coupled with said actuator and adapted for determining a retract direction for said readwrite head, wherein a first signal indicative of a first direction and a second signal indicative of a second direction are provided to said actuator, said control device further providing said first signal responsive to a power off condition and providing said second signal subsequent to providing said first signal for retracting said readwrite head to said landing position,
wherein said control device provides said second signal at a predetermined time period following said power off condition,
wherein said control device provides said second signal at a time based on the phase crossing of the disk drive motor of said disk drive system subsequent to said power off condition.
3. The system of claim 2 further including a brake for braking said disk drive motor following retraction of said readwrite head to said landing position.
4. A method for retracting a readwrite head to a landing position of a disk in a disk drive system, said method comprising:
generating a first signal indicative of a first direction following a loss of power which energizes the disk drive motor of said disk drive system and a second signal indicative of a second direction;
retracting said readwrite head in said first direction toward an outside diameter of said disk responsive to applying said first signal to an actuator coupled with said readwrite head; and
retracting said readwrite head in said second direction toward an inside diameter of said disk responsive to applying said second signal to said actuator,
further including retracting said readwrite head to an outside diameter stop responsive to application of said first signal.
5. The method of claim 4 further including retracting said readwrite head to said landing position on an inside diameter of said disk responsive to application of said second signal.
6. The method of claim 4 further including determining the speed of said disk drive motor following loss of power and generating said second signal based on a speed reduction.
7. The method of claim 4 further including braking said disk drive motor following retraction of said readwrite head to said landing position.
8. The method of claim 4 further including providing said second signal when said disk drive motor has slowed to a predetermined speed following loss of power.
9. A method for retracting a readwrite head to a landing position of a disk in a disk drive system, said method comprising:
generating a first signal indicative of a first direction following a loss of power which energizes the disk drive motor of said disk drive system and a second signal indicative of a second direction;
retracting said readwrite head in said first direction toward an outside diameter of said disk responsive to applying said first signal to an actuator coupled with said readwrite head; and
retracting said readwrite head in said second direction toward an inside,
further including retracting said readwrite head to said inside diameter following arrival of said readwrite head at an outside diameter stop.
10. A method for retracting a readwrite head to a landing position of a disk in a disk drive system, said method comprising:
generating a first signal indicative of a first direction following a loss of power which energizes the disk drive motor of said disk drive system and a second signal indicative of a second direction;
retracting said readwrite head in said first direction toward an outside diameter of said disk responsive to applying said first signal to an actuator coupled with said readwrite head; and
retracting said readwrite head in said second direction toward an inside,
comparing a predetermined reference voltage with a b-emf voltage produced by said disk drive motor for determining the timing of said second signal.
11. A method for retracting a readwrite head to a landing position of a disk in a disk drive system, said method comprising:
generating a first signal indicative of a first direction following a loss of power which energizes the disk drive motor of said disk drive system and a second signal indicative of a second direction;
retracting said readwrite head in said first direction toward an outside diameter of said disk responsive to applying said first signal to an actuator coupled with said readwrite head; and
retracting said readwrite head in said second direction toward an insides,
providing said second signal at a time based on the phase crossing of said disk drive motor subsequent to loss of power.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A servicing rig for a well adapted to communicate with a fluid source and an effluent reservoir, said rig comprising:
a base;
a coiled tubing apparatus on said base for holding and dispensing coiled tubing; and,
a manifold assembly on said base for routing pressurized fluid from said fluid source between said coiled tubing apparatus, said well and said effluent reservoir.
2. The servicing rig of claim 1 wherein said manifold assembly includes means for controlling the flow of said fluid through said assembly to selectively form at least one of a first fluid route to perform fracturing operations, a second fluid route for reverse fluid circulation, a third fluid route for a common coiled tubing operation, and a fourth fluid route for pressure testing.
3. The servicing rig of claim 2 wherein said means for controlling comprises an arrangement of remotely controlled valves and pressure transducers.
4. The servicing rig of claim 2 wherein said first and second fluid routes include means of diffusing energy of said fluid prior to proceeding to said effluent reservoir.
5. The servicing rig of claim 1 wherein said coiled tubing apparatus comprises a rotatable reel mounted on said base for holding and dispensing coiled tubing and a pivotable mast operatively mounted to said base, said manifold assembly being located intermediate said reel and mast.
6. The servicing rig of claim 1 wherein said base comprises a mobile carrier.
7. A manifold assembly for routing a fluid from a fluid source between a wellbore annulus, an effluent reservoir and a tubing apparatus on a well servicing unit, said assembly comprising:
an inlet for receiving said fluid;
a first line in fluid communication with said inlet and tubing apparatus;
a second line in fluid communication with said first line and said annulus;
a third line in fluid communication with said first line and said effluent reservoir;
a fourth line in fluid communication between said second and third lines;
wherein said first, second, third and fourth lines are adapted for location on said well servicing unit.
8. The manifold assembly of claim 7 further comprising means for controlling the flow of said fluid through said assembly to selectively form at least one of a first fluid route to perform fracturing operations, a second fluid route for reverse fluid circulation, a third fluid route for a common coiled tubing operation, and a fourth fluid route for pressure testing.
9. The manifold assembly of claim 8 wherein said means for controlling includes a first remotely controlled valve located on said first line intermediate said second and third lines, a second remotely controlled valve on said first line downstream of said third line, a third remotely controlled valve located on said third line intermediate said first and fourth lines, a fourth remotely controlled valve located on said second line intermediate said first and fourth lines, and a fifth remotely controlled valve on said fourth line.
10. The manifold assembly of claim 7 wherein said third line includes choke means for diffusing fluid energy prior to entering said effluent reservoir.
11. The manifold assembly of claim 8 wherein said third line includes choke means for diffusing fluid energy prior to entering said effluent reservoir.
12. The manifold assembly of claim 9 wherein said third line includes at least one choke downstream of said fourth line for diffusing fluid energy prior to entering said effluent reservoir, and wherein said means for controlling further includes further remotely controlled valves for each choke.
13. A method of servicing an underground formation comprising:
providing a fluid storage means;
providing a fluid pumping means capable of drawing fluid from said fluid storage means and supplying a sufficient fluid stream under sufficient pressure for servicing said underground formation;
providing a coiled tubing unit for receiving and introducing said fluid stream into said underground formation, said unit having a manifold assembly for routing and controlling said fluid stream between said unit and said underground formation; and,
providing an effluent reservoir for receiving fluid from said manifold assembly.
14. The method of claim 13 wherein said fluid comprises nitrogen gas.
15. The method of claim 14 further comprising introducing proppant into said nitrogen gas prior to being received by said coiled tubing unit.
16. The method of claim 15 wherein said proppant comprises sand.
17. The method of claim 15 comprising providing a high-pressure injection proppant system for introducing said proppant upstream of said coiled tubing unit and downstream of said pumper.
18. The method of claim 13 comprising providing a crew truck for supplying fuel to said pumper and coiled tubing unit.
19. The method of claim 13 wherein said coiled tubing unit includes a tubing apparatus and communicates with an effluent reservoir, and said manifold assembly comprises:
an inlet for receiving said fluid stream;
a first line in fluid communication with said inlet and said tubing apparatus;
a second line in fluid communication with said first line and said underground formation;
a third line in fluid communication with said first line and said effluent reservoir; and,
a fourth line in fluid communication between said second and third lines.
20. The method of claim 13 wherein said manifold assembly includes means for controlling the flow of said fluid stream through said assembly to selectively form at least one of a first fluid route to perform fracturing operations, a second fluid route for reverse fluid circulation, a third fluid route for a common coiled tubing operation, and a fourth fluid route for pressure testing.