Coiled tubing systems and methods for geothermal wells

1 . A coiled tubing system, comprising:

a coiled tubing string configured to couple to a downhole tool to move the downhole tool along a geothermal well;

an injector head configured to control movement of the coiled tubing string and the downhole tool along the geothermal well, wherein the injector head comprises:

one or more chains configured to engage the coiled tubing string to move the coiled tubing string;

a motor coupled to the one or more chains to drive operation of the one or more chains; and

a brake configured to engage the motor to stop the movement of the coiled tubing string along the geothermal well;

one or more sensors configured to capture sensor data indicative of a distance traveled by the coiled tubing string along the geothermal well; and

a controller configured to control operation of the injector head to move the coiled tubing string and the downhole tool to a measured depth within the geothermal well that corresponds to an intersection of a feature with the geothermal well based on the sensor data received from the one or more sensors.

2 . The coiled tubing system of claim 1 , wherein controlling operation of the injector head comprises:

operating, via the controller, the motor to drive the one or more chains to bias the coiled tubing string and the downhole tool toward the measured depth; and

sending a control signal, via the controller, to the brake to cause the brake to engage the motor to stop the movement of the coiled tubing string based on the distance traveled by the coiled tubing string corresponding to the measured depth.

3 . The coiled tubing system of claim 2 , wherein controlling operation of the injector head comprises:

after sending the control signal to the brake to cause the brake to engage the motor, operating, via the controller, the motor to drive the one or more chains to bias the coiled tubing string and the downhole tool toward a second measured depth that corresponds to a second intersection of a second feature with the geothermal well, wherein the measured depth and the second measured depth are separated by a particular distance; and

sending an additional control signal, via the controller, to the brake to cause the brake to engage the motor to stop the movement of the coiled tubing string based on the distance traveled by the coiled tubing string corresponding to the particular distance.

4 . The coiled tubing system of claim 2 , wherein the controller is positioned less than a threshold distance away from the injector head such that the control signal from the controller to the brake travels less than the threshold distance to cause the brake to engage the motor.

5 . The coiled tubing system of claim 4 , wherein the threshold distance is five meters.

6 . The coiled tubing system of claim 4 , wherein the control signal causes the brake to engage the motor in less than a threshold amount of time.

7 . The coiled tubing system of claim 2 , wherein the brake is configured to discharge hydraulic fluid in response to receiving the control signal from the controller to cause the brake to engage the motor, and wherein the coiled tubing system comprises a case drain configured to receive the hydraulic fluid from the brake.

8 . The coiled tubing system of claim 7 , wherein the case drain is not coupled to other components of the coiled tubing system.

9 . The coiled tubing system of claim 7 , wherein the case drain is positioned less than a threshold distance away from the injector head.

10 . The coiled tubing system of claim 7 , wherein the case drain is mounted to the injector head.

11 . A method for locating a downhole tool in a geothermal well using a coiled tubing system, the method comprising:

analyzing subsurface data to determine respective locations of a plurality of features that intersect the geothermal well;

operating, via a controller, an injector head of the coiled tubing system to deploy the downhole tool toward a first location of a first feature of the plurality of features, wherein the first location comprises a measured depth along the geothermal well;

operating, via the controller, the injector head using one or more dynamic models configured to account for one or more dynamic downhole conditions;

receiving, via one or more sensors, sensor data indicative of a distance traveled by a coiled tubing string of the coiled tubing system coupled to the downhole tool;

determining, via the controller, that the distance traveled by the coiled tubing string corresponds to the measured depth based on the sensor data; and

causing, via the controller, the injector head to stop movement of the coiled tubing string in response to determining that the distance traveled by the coiled tubing string corresponds to the measured depth of the first feature.

12 . The method of claim 11 , wherein the dynamic downhole conditions comprise a flow rate of fluid directed through the coiled tubing string, wherein the flow rate of fluid directed through or along the coiled tubing string causes the coiled tubing string to elongate by a particular distance within the geothermal well, and wherein the method comprises causing, via the controller, the injector head to stop movement of the coiled tubing string in response to determining that a sum of the distance traveled and the particular distance corresponds to the measured depth of the first feature.

13 . The method of claim 11 , wherein the downhole tool comprises an abrasive perforated gun (APG) having one or more nozzles, wherein the dynamic downhole conditions comprise a rate of degradation of the one or more nozzles, and wherein the method comprises:

operating the one or more nozzles to inject a fluid at a first flow rate into the first feature;

determining that the rate of degradation exceeds a degradation threshold; and

operating the one or more nozzles to inject the fluid at a second flow rate that is greater than the first flow rate based on the rate of degradation of the one or more nozzles exceeding the degradation threshold.