More Roller Bogie® Successes in Open Hole Wireline Operations
An open hole logging operation was recently carried out in a deviated offshore well in eastern Malaysia. With well inclination up to 62°, it had been normal practice in similar wells to use pipe-conveyed logging methods but on this occasion it was decided to explore the possibility of running logs on wireline, using new open hole Roller Bogie® tools from Wireline Engineering Ltd to overcome the usual limitations of higher deviation.
As well as significantly reducing the time and cost of the logging programme, one of the stated objectives was to be able to run certain logging tools that are not recommended for use on pipe-conveyed operations.
Predictive software indicated that logs could only be run in this well using pipe-conveyed techniques. When re-modelled using Roller Bogie® tools, the wire-tension planner suggested that wireline could indeed be used. With better data collection and very significant cost savings to be made if successful, the Roller Bogie® option was selected.
Logging was conducted in 8 ½” hole with nearly 2000m of open hole to be negotiated, almost 700m of which was at or above 60°. Two logging runs were planned, using three Roller Bogie® tools in each run.
Run #1 saw the toolstring conveyed to bottom at the first attempt. No over-pulls were noted while logging across the entire openhole section and good quality logs were obtained.
Run #2 comprised a 25m+ toolstring, including 15m+ of large OD sampling assembly. This was conveyed successfully until it hung up in open hole where surveys showed a “hump” in the well path. The tools were retrieved and the length of larger diameter tools reduced to be able to navigate the dogleg more easily.
Run #3 comprised a 23m+ toolstring conveyed successfully to bottom at the first attempt and a successful logging operation completed without incident.
The first thing noted by the operating company was a more constant head tension using roller bogies and the absence of the “slip stick” sometimes seen with pipe-conveyance, giving an improved quality of data. Better weight and depth indication was also recorded, allowing more accurate zonal identification.
As a conveyance solution in open hole in a deviated well, Roller Bogie® tools proved to be an effective product. The huge gain was being able to have the convenience of running a successful logging operation on wire while saving a large number of rig hours to run and retrieve a pipe conveyed logging system. The cost benefits are obvious. The time saved retrieving and reconfiguring the sampling toolstring alone saved enough cost to justify the decision to use Roller Bogie® tools.