Ann: Quarterly Report & Cashflow, page-51

From memory this was referring to the main borehole not the sidetrack. That said I wouldn't be surprised if there was also significant cake build up in the sidetrack as well given there was differential sticking going on. One obvious sign of overly thick mud cake is when your logging tools come out of the hole covered in the stuff...one of many things I used to check during a logging job and note.

The probe on a formation test tool is designed to extend out from the tool mandrel far enough to penetrate any mud cake and seal against formation in the borehole wall. If mud cake is too thick then the probe will fail to reach the formation and you wont be able to flow any fluid into the tool flowline.