"The RFT tool got stuck with differential sticking. That is a sign of low permeability and low porosity." "But the mudcake in thick low perm zones is most often the cause. "
Comments:
1) The RFT is a Schlumberger tool that came out in the mid 70's and was superceded by the MDT in the late 80's. IVZ were running a Baker tool...the RCX. 2) For differential sticking to occur you need two things: 1) a high permeability zone and 2) a large difference between borehole pressure and formation pressure. 3) To get a thick mudcake buildup you need significant filtrate invasion into the formation. For filtrate invasion to occur you need permeability. The borehole caliper log is a good rough indicator of permeability. Where the caliper reads undergauge you usually have mud cake build up due to permeability. Low permeability sands often wash out and show up as under gauge hole on the caliper
IVZ Price at posting:
14.5¢ Sentiment: Buy Disclosure: Held
