Multi-sensor workflow for evaluation of water flow in multiple casing strings

A well system, comprising:

• a tool string conveyable into a wellbore drilled through one or more subterranean formations, the tool string including at least a pulsed neutron sensor, a noise sensor, a Doppler sensor, and a temperature sensor;
• and
• a computer system including a processor and a non-transitory computer readable medium, the computer system communicatively coupled to the tool string, and the computer readable medium stores a computer readable program code, when executed by the processor, configures the processor to:
• operate the pulsed neutron sensor to obtain pulsed neutron log (PNL) data from the wellbore;
• calculate a first distance of a flow path from the tool string and a first velocity of a water flow in the flow path using a pulsed neutron log borehole model and the PNL data, the flow path located at a cement interface in the wellbore;
• operate the noise sensor to obtain noise log (NL) data from the wellbore;
• calculate a second distance of the flow path from the tool string and a second velocity of the water flow in the flow path using a noise log borehole model and the NL data;
• compare the first distance and the first velocity with the second distance and the second velocity, respectively, to obtain a first calculated distance of the flow path and a first calculated velocity of the water flow in the flow path;
• operate the Doppler sensor to obtain Doppler log (DL) data from the wellbore;
• calculate a third distance of the flow path from the tool string and a third velocity of the water flow in the flow path using a Doppler borehole model and the DL data;
• compare the third distance and the third velocity with the first calculated distance and first calculated velocity, respectively, to obtain a second calculated distance of the flow path and a second calculated velocity of the water flow in the flow path;
• operate the temperature sensor to obtain temperature data from the wellbore;
• calculate a fourth distance of the flow path from the tool string and a fourth velocity of the water flow in the flow path using a temperature borehole model and the temperature data;
• and
• compare the fourth distance and the fourth velocity with the second calculated distance and the second calculated velocity, respectively, to determine a width of the cement interface, a distance of the cement interface from the tool string, and a velocity of a water flow in the cement interface.