Wellbore reverse circulation with flow-activated motor

A method, comprising:

• introducing a work string into a wellbore, the work string including a flow-activated motor having a housing and a driveshaft rotatably positioned within the housing and a rotating agitator tool coupled to the driveshaft such that rotation of the driveshaft correspondingly rotates the rotating agitator tool, the driveshaft being coupled to a plurality of rotor vanes;
• pumping a fluid into an annulus defined between the work string and the wellbore with a pump;
• receiving at least some of the fluid through one or more bullnose ports defined in the housing and into an interior of the housing, the one or more bullnose ports being positioned axially between the rotating agitator tool and the plurality of rotor vanes;
• receiving at least some of the fluid through one or more nozzle ports defined in the rotating agitator tool, through a fluid conduit defined in the driveshaft, and into the interior of the housing, the fluid conduit extending to a portion of the driveshaft that is axially between the one or more bullnose ports and the plurality of rotor vanes;
• impinging the fluid on the plurality of rotor vanes and thereby rotating the driveshaft;
• rotating the rotating agitator tool and thereby engaging and loosening debris in the wellbore;
• and
• entraining the debris in the fluid and flowing the debris through the flow-activated motor with the fluid.

A well system, comprising:

• a work string extendable into a wellbore;
• a pump that pumps a fluid into an annulus defined between the work string and the wellbore;
• a flow-activated motor coupled to the work string and having a housing that receives the fluid pumped into the annulus, the flow-activated motor further including a driveshaft rotatably positioned within an interior of the housing and a plurality of rotor vanes coupled to the driveshaft, wherein the driveshaft rotates as the fluid flows through the housing and impinges on the plurality of rotor vanes;
• a rotating agitator tool coupled to the driveshaft such that rotation of the driveshaft correspondingly rotates the rotating agitator tool, wherein the rotating agitator tool engages and loosens debris in the wellbore while rotating and the debris is entrained in the fluid and flows through the flow-activated motor;
• one or more bullnose ports defined in the housing to receive at least some of the fluid into the interior of the housing, the one or more bullnose ports being positioned axially between the rotating agitator tool and the plurality of rotor vanes;
• one or more nozzle ports defined in the rotating agitator tool to receive at least some of the fluid;
• and
• a fluid conduit defined in the driveshaft to conduct the fluid from the one or more nozzle ports to the interior of the housing, the fluid conduit extending to a portion of the driveshaft that is axially between the one or more bullnose ports and the plurality of rotor vanes.