2penetration rate charge this is one of primary

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Unformatted text preview: 05 by Ali Ghalambor & Boyun Guo 63 1. Detection Methods There have been larger number of techniques developed to detect and quantify abnormal pressures, See page No.2 for detail. 2.Penetration Rate Charge This is one of primary indicators for abnormal pressures because of its ease in observation. Maximum penetration rates can be attained when the mud hydrostatic pressure is approximately equal to the formation pressure. The relationship can be seen in Fig.1 where the differential pressures is the difference between the mud hydrostatic pressure and the formation fluid pressure. Fig.1 Effect of differential pressure on drilling rate Copyright(c) 2005 by Ali Ghalambor & Boyun Guo 128 64 3. Shale Density Charge: The porosity in abnormally pressured zones will be greater than normal, the density of the shale will be less than normal due to the high water content in the porosity. Any deviation from a normal shale density increase will indicate abnormal porosities which detect abnormal pressures. 4. Mud Chloride Change: Also a result of the high rock...
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This document was uploaded on 03/28/2014.

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