Drill bit with extendable gauge pads

1. A drill bit, comprising:

a bit body having a longitudinal axis;

a blade of a selected length on a side of the bit body and substantially along a longitudinal direction; and

a movable member on the side of the bit body associated with the blade that extends from a retracted position to a selected extended position along the longitudinal axis to effectively extend the selected length of the blade when the movable member is in the selected extended position.

2. The drill bit of claim 1 , wherein the movable member is placed inside the blade.

3. The drill bit of claim 2 further, comprises a device that extends and retracts the movable member.

4. The drill bit of claim 3 , wherein the device comprises:

a fluid chamber and wherein the movable member is in fluid communication with the fluid chamber; and

a device to supply a fluid under pressure to the fluid chamber to extend the movable member from a retracted position.

5. The drill bit of claim 3 further, comprising a biasing member that biases the movable member to cause the movable member to move toward the retracted position.

6. The drill bit of claim 3 , wherein the device includes a motor that controls a pump to supply a fluid under pressure to move the movable member.

7. The drill bit of claim 6 , wherein the fluid is one of: (i) drilling fluid flowing through the drill bit; and (ii) a hydraulic fluid stored in the drill bit.

8. The drill bit of claim 1 , wherein the drill bit includes a plurality of blades, each blade including a separate movable member associated therewith that extends along the longitudinal axis of the drill bit.

9. The drill bit of claim 1 , further comprising a sensor that provides information relating to n extension of the movable member.

10. The drill bit of claim 1 further, comprising a controller that controls an extension of the movable member.

11. A method of making a drill bit, comprising:

providing a drill bit having a blade of a selected length along a side of a bit body having a vertical axis; and

providing a movable member on the side of the bit body that extends from a retracted position along the vertical axis to a selected extended position that effectively extends the selected length of the blade when the movable member is in the selected extended position.

12. The method of claim 11 , further comprising placing the movable member in a recess in the blade.

13. The method of claim 12 , further comprising providing a fluid device that provides fluid under pressure to move the movable member from a retracted position to the selected extended position.

14. The method of claim 13 , further providing a force device to move the movable member from the selected extended position to the retracted position.

15. The method of claim 13 , wherein the fluid device includes a fluid flow control device that allows application of the fluid to the selected member to extend the selected member from the retracted position to the selected extended position.

16. The method of claim of claim 15 , wherein the flow control device is one of: a pump; and a valve.

17. A method of drilling a wellbore, comprising:

conveying a drill string having a drill bit at an end thereof, wherein the drill bit includes:

a bit body having a blade of a selected length along a side of the bit body, the bit body having a longitudinal axis; and a movable member on the side of the bit body that extends from a retracted position along the longitudinal axis to a selected extended position to effectively extend the selected length of the blade when the moveable member is in the selected extended position; and

drilling the wellbore using the drill string.

18. The method of claim 17 , further comprising extending the movable member to the selected extended position when drilling a vertical well section.

19. A drilling system, comprising:

a drilling assembly having a drill bit at an end thereof configured to drill a wellbore, wherein the drill bit includes:

a bit body having a blade of a selected length along a side of the bit body, the bit body having a vertical axis; and

a movable member on the side of the bit body that extends from a retracted position to a selected extended position along the longitudinal axis to effectively extend the selected length of the blade when the movable member is in the selected extended position.

20. The drilling system of claim 19 , wherein the movable member includes a fluid flow device that moves the movable member from a retracted position to the selected extended position.

21. The drilling system of claim 20 , further comprising a controller that controls the operation of the fluid flow device.

22. The drilling system of claim 21 , wherein the controller is located at one of: a surface location; in the drilling assembly; in the drill bit; and partially in at least the drilling assembly and a surface location.