Hole spiraling

25 March 2010 Gents,
We drill appraisal deep tight gas well around 5000m TVD. The formation in 8.5" hole mostly limestone interbedded with dolomite and some sandstone/siltstone. The UCS of the rock within 15000 - 30000 psi range. Drilling challenges are hardrock, abrassive, experience ROP 1 m/hr in some formation including reservoir. We drill this section using turbine and impreg (long gauge), this is the most economic choice since we deal with hardrock formation.

Based on the image log from 5 wells we drill, I saw spiraled hole in this section. Although I did not see any problem associated with spiraled hole currently, it may become high risk when we drill horizontal well next time.

Is there anyone have the same experience with this problem? How to mitigate this problem?

Thanks
Army Ardian

BP Oman

6 Answer(s)

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