Motor rotor fish recovery in a long horizontal section
GY16-Q19-H37 has an artificial bottom of 5569 m and an approximately 3000 m horizontal section. After the 3 1/8 in motor worked for 140 hours, the rotor pulled out and remained downhole. The fishing plan focused on long-lateral conveyance, fish-top approach, low-speed rotary assistance, and reliable slip engagement.
Challenge
The rotor fish was long and slender, located in a deep long horizontal interval where CT conveyance friction was high. The fishing BHA needed to approach the fish top, support controlled rotary assistance, and provide reliable slip engagement.
Tool string
The BHA used connector, check valve, hydraulic release, low-speed motor, 105×51 slip overshot, and extended-barrel structure. The low-speed motor supported fish-top approach and conditioning, while the extended barrel improved guidance and engagement stability.
Fishing process
The tool string was conveyed through the long lateral and gradually approached the fish. Low-speed rotation and controlled set-down improved fish-entry conditions. The slip overshot and extended barrel then supported engagement judgement based on weight response.
Field result
The motor rotor fish was recovered to surface. The recovered rotor and connection area confirmed the downhole failure mode and provided direct evidence for the fishing process review.
Review value
The case shows that motor rotor fish recovery by CT should be designed as an integrated tool string covering conveyance, fish-top conditioning, entry guidance, and slip engagement. A low-speed motor with extended-barrel slip overshot improves control in long-lateral fishing work.