Chemical Effect on Wellbore Instability of Nahr Umr Shale

Table 3

Mineral composition and content of the Nahr Umr Shale.

Depth	Mineral content (%)
	Quartz	Potassium feldspar	Soda feldspar	Anorthose	Calcite	Dolomite	Iron pyrite	Hematite	TCCM
3645.10	51.7	0.8		0.2				2.7	44.6
3649.83	60.8	1.2			0.4		4.7		32.9
3666.00	48.5	1.9		0.3	1.4		4.5		43.4