Abstract
An operator in west Texas experienced an obstruction pumping down a plug and perforating gun combination on a multi-stage frac operation in a 23,600-ft lateral. Following a 3.74" OD gauge run with 2-3/8" coiled tubing (CT), which hung up at 18,266 ft, a 3" gauge run was able to pass the holdup depth (HUD). To determine the cause of the restriction, the operator decided to run a video camera and a multi-finger caliper tool. However, due to some concerns with CT reach in the long lateral, issues with friction reducers, undesirable memory timers for recording the logs, and the inability to repeat logging in zones of interest or missing data, the camera provider recommended the logging be performed in "real time" on an electric-line (e-line) tractor.
A shop systems integration test of the combined tractor, caliper and camera was performed prior to running in the well. Clear fluid (fresh water) was pumped down the 5.5" × 4.5" casing from surface to obtain quality video downhole. Upon running the live system with the tractor, several over-torqued collars were identified as well as some buckling above those collars. The images were clear, and the problem areas were successfully identified. The total distance tractored was 10,063 ft, passing through the bad collars to the total measured depth of 23,511 ft.
This was the first time that a downhole video camera was run in combination with a multi-finger caliper tool on an e-line tractor in one run. This service benefits the industry in the following ways:
Flexible logging program with real time diagnostics and decisions on additional passes in problem areas.
No fluid darkening friction reducers necessary to achieve long lateral total depth.
No CT helical buckling concerns.
Small foot print for logging program on multi-well pads.
Less chance of damaging logging tools on tractor than on CT if obstructions encountered.
This paper describes the operational details of this case and offers insights into the potential uses for such a service to the industry.
