Freeing stuck tubulars in wellbores

1. An apparatus comprising:

a tubular;

three pressure sensors distributed along an outer circumference of the tubular;

three expandable pads distributed along the outer circumference of the tubular;

a hydraulic chamber disposed within the tubular, the hydraulic chamber configured to expand each of the expandable pads independently; and

a computer system disposed within the tubular, the computer system comprising:

a processor; and

a storage medium interoperably coupled to the processor and storing programming instructions for execution by the processor, the programming instructions instructing the processor to perform operations comprising:

in response to determining that the tubular is stuck within the wellbore:

determining a locale of sticking of the tubular based on the pressure readings transmitted by the pressure sensors; and

transmitting a pressure signal to cause the hydraulic chamber to pressurize one or more of the expandable pads that are closest to the locale of sticking of the tubular, thereby causing the one or more expandable pads to expand and exert a force necessary to free the tubular.

2. The apparatus of claim 1 , wherein the programming instructions instruct the processor to perform operations comprising determining that the tubular is stuck within the wellbore based on the pressure readings transmitted by the pressure sensors.

3. The apparatus of claim 2 , wherein the programming instructions instruct the processor to perform operations comprising:

determining the force necessary to free the tubular based on the pressure readings transmitted by the pressure sensors; and

determining a corresponding pressure necessary in the hydraulic chamber to expand the one or more expandable pads and exert the force to free the tubular.

4. The apparatus of claim 1 , comprising three circulating ports distributed along the outer circumference of the tubular, and wherein the programming instructions instruct the processor to perform operations comprising transmitting a circulation signal to cause one or more of the circulating ports to open and allow circulation of drilling fluid out of the tubular.

5. The apparatus of claim 4 , wherein the expandable pads are positioned on the tubular between the circulating ports and the pressure sensors.

6. The apparatus of claim 1 , wherein a distribution of the expandable pads along the outer circumference of the tubular is the same as a distribution of the pressure sensors along the outer circumference of the tubular.

7. A method comprising:

detecting pressure, by three pressure sensors, at three locations corresponding to a distribution of the three pressure sensors along an outer circumference of a tubular disposed within a wellbore; and

by a computer system disposed within the tubular:

determining that the tubular is stuck within the wellbore based on the detected pressures;

in response to determining that the tubular is stuck within the wellbore:

determining a locale of sticking of the tubular based on the detected pressures;

determining a force necessary to free the tubular based on the detected pressures;

determining a pressure necessary in a hydraulic chamber to exert the force necessary to free the tubular; and

transmitting a pressure signal to cause the hydraulic chamber to pressurize one or more expandable pads that are closest to the locale of sticking of the tubular, thereby causing the one or more expandable pads to expand and exert the force to free the tubular.

8. The method of claim 7 , wherein the apparatus comprises three circulating ports distributed along the outer circumference of the tubular, and the method comprises transmitting, by the computer system, a circulation signal to cause one or more of the circulating ports to open and allow circulation of drilling fluid out of the tubular.

9. A method comprising:

receiving a plurality of pressure readings from a plurality of pressure sensors distributed along an outer circumference of a tubular disposed within a wellbore;

determining that the tubular is stuck within the wellbore based on the plurality of pressure readings; and

in response to determining that the tubular is stuck within the wellbore:

determining a locale of sticking of the tubular based on the plurality of pressure readings; and

transmitting a signal to cause one or more expandable pads that are closest to the locale of sticking of the tubular to expand and exert a force to free the tubular.

10. The method of claim 9 , comprising determining a force necessary to free the tubular based on the plurality of pressure readings.

11. The method of claim 10 , comprising determining a corresponding pressure necessary in a hydraulic chamber disposed within the tubular to exert the force to free the tubular.

12. The method of claim 11 , wherein the signal causes the hydraulic chamber to pressurize the one or more expandable pads distributed along the outer circumference of the tubular that are closest to the locale of sticking of the tubular, thereby causing the one or more expandable pads to expand and exert the force to free the tubular.

13. The method of claim 12 , comprising transmitting a circulation signal to one or more circulating ports distributed along the outer circumference of the tubular to cause the one or more circulating ports to open and allow circulation of drilling fluid out of the tubular.

14. The method of claim 13 , wherein the circulation signal is transmitted after the signal that causes the force to be exerted to free the tubular.