5-14-2015

Quant analysis.pdf

XRD scan.jpg

As you are probably aware, severe difficulties have been encountered in the Presho2 hole.  The cuttings from the Niobrara are extremely viscous and are causing the pipe to torque up.  Sarah and I collected a sample of the drill cuttings from the edge of the plastic bucket used to move cuttings from the rig to the disposal area and I arranged to have an XRD analysis performed.  Russ appears to be correct in that the mineralogy looks rather ordinary and seems to be from a shale unit as opposed to a carbonate unit given the low calcite content.  This points to an issue that is related to the mud additive, perhaps.

 The plastic fibers that Russ references are a few fibers that are about 1 cm long, which he found during crushing of the samples for the XRD analysis.  It is not clear whether they are volumetrically important in the cuttings or even whether they are a contaminant from the bucket although that seems unlikely.

Bill Roggenthen

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Message from Russ Lingenfelter, SDSMT EMES, that refers to the sample collected above. 

From: Lingenfelter, David R. (SDSM&T)
Sent: Thursday, May 14, 2015 9:50 AM
To: Roggenthen, William M.
Subject: Drill cuttings

I’ve analyzed the sample, it looks pretty ordinary as far as minerals are concerned.

Approximately:

45% Quartz

40% Montmorillonite

  9% Muscovite

  4% Kaolinite

  2% Calcite

I think your problem may be caused by the plastic fibers I found in the sample. 

Russ Lingenfelter

SDSMT-EMES

501 E. Saint Joseph St.

Rapid City, SD  57701

(605) 394-2380