10,323
edits
Changes
Jump to navigation
Jump to search
Line 110:
Line 110: − + Line 244:
Line 244: − +
Quick-look lithology from logs (view source)
Revision as of 21:15, 11 January 2016
, 21:15, 11 January 2016no edit summary
====Tight rocks====
====Tight rocks====
An SP log is of little use in the absence of boundaries between shale beds and permeable beds. In relatively tight rocks (carbonates, evaporites, etc.), the SP wanders aimlessly, with no sharp usable deflections.
An SP log is of little use in the absence of boundaries between shale beds and permeable beds. In relatively tight rocks (carbonates, [[evaporite]]s, etc.), the SP wanders aimlessly, with no sharp usable deflections.
====Log shapes====
====Log shapes====
* ''Gypsum and anhydrite''. The typical neutron porosity value in anhydrite (CaSO<sub>4</sub>) is close to zero, but that in gypsum (CaSO<sub>4</sub> • 2H<sub>2</sub>O) is much higher—up to 60%.
* ''Gypsum and anhydrite''. The typical neutron porosity value in anhydrite (CaSO<sub>4</sub>) is close to zero, but that in gypsum (CaSO<sub>4</sub> • 2H<sub>2</sub>O) is much higher—up to 60%.
* ''Potash Evaporites''. Sylvite is anhydrous with a near-zero neutron porosity, but carnallite (KMgCl<sub>3</sub> • 6H<sub>2</sub>O) gives neutron values of 30% to 60%.
* ''Potash [[Evaporite]]s''. Sylvite is anhydrous with a near-zero neutron porosity, but carnallite (KMgCl<sub>3</sub> • 6H<sub>2</sub>O) gives neutron values of 30% to 60%.
====Bound water in shale====
====Bound water in shale====