Removing debris in extended unconventional

Challenge
Unconventional wells
JUSST142949 Removing Debris
  • Well type Oil well
  • Max. deviation 89°
  • TDV 13,092 ft
  • MD 17,000 ft
  • Max. temperature 325°F

Background

Multiple failed attempts to convey a production logging string on Coiled Tubing (CT) in extended horizontals led an operator in Eagle Ford, Texas, to look for an alternative method. The operator suspected that a specific type of debris from a previous frac plug milling operation had not been picked up on the CT clean out run. It was believed that the debris caused the CT to reach early lock-up and also to get stuck in the well at one point.

The horizontal section stretched for 4,681 ft with a maximum deviation of 89°, which made the operation perfectly suited for the e-line Well Tractor®. In addition, the operator had applied Welltec’s cleanout solutions with great success before and trusted they could remove the debris in order to clear the path for a Well Tractor conveyed PLT run.

Operation

A System Integration Test (SIT) was conducted with different tool configurations and some actual debris samples. The SIT results demonstrated to the operator that Welltec’s solution would be the ideal method. The objective was then set to run the Well Cleaner® Power Suction Tool High Flow (PST HF) with the Well Tractor XR in order to pick up the mixed material composite buttons from the frac plugs that CT was not able to lift.

Two runs were completed with three bailer sections each. On the first run, the tool-string stopped 1,000 ft before Total Depth (TD) whereas the second run ran all the way along the horizontal section until reaching TD. A total of five gallons of debris was recovered from the well, including hardware from the milled frac plugs and some type of a viscous gel.

Achievements

Post clean out, the Well Tractor conveyed the suspended PLT to TD, thus completing the operation.

The operator is now analyzing the debris that the Well Cleaner PST retrieved from the well, which will allow them to optimize the planning of future cleanouts. Welltec’s performance also proved to them the ease with which Well Tractors can convey logging runs in extended reach wells.

Additional benefits from this e-line intervention include ease of logistics to mobilize, no need for tanks of fluids as the Well Cleaner PST works on suction versus injection and that it can be run in a producing well without shutting it in. This provides fast load-out, continued production and efficient operations since there is no need to let the well stabilize after a CT clean-out where large amounts of fluids are pumped into the well.