Rock Cuttings from the Hibernia Field

Rock “cuttings” samplesHibernia Field

Offshore East Coast Canada

Examples provided by Glenn Power, (geologist)

This PowerPoint Presentation is intended for ‘non-technical’ persons.

The contents were initially generated (circa 1998) to share with co-workers on the Hibernia Platform (from kitchen staff to the ‘rig bosses’) who were frequently curious about ‘what we were drilling into’.

I took pictures of the “drill cuttings” and posted them in public places on the Hibernia Platform so that all could share in what even I as a geologist found to be ‘awesome’.

At that time, I also took pictures of the microscopic fossils that I encountered in the drill “cuttings”. I have assembled another PowerPoint Presentation that has those photos.

http://www.slideshare.net/GlennPower/fossilsoffshorehibernia

Additionally, there is another PowerPoint Presentation that helps to explain how oil is formed, how we look for it, and how we get it out of the ground.

http://www.slideshare.net/GlennPower/oil-patch-broad-overview-for-non-technicals

I am happy to share these with the public so that we can all appreciate what we frequently take for granted. Oil and Gas.

Glenn Power, (geologist)

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Sandstone, light grey to tan (where oil-stained), fine to very fine grained with occasional medium grains, ‘sugary’ texture. Upper Hibernia Formation.(20X Magnification)

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Sandstone, light grey, fine to very fine grained with occasional medium grains, ‘sugary’ texture. Trace bitumen, trace oil staining.Upper Hibernia Formation. (20X Magnification)

Sandstone, light grey to tan where heavily oil-stained, fine grained with occasional medium grains, ‘sugary’ texture. Trace bitumen and coaly laminations (black layers), Middle Hibernia Formation. (20X Magnification)

Sandstone, light grey to tan where heavily oil-stained, fine grained with occasional medium grains, ‘sugary’ texture. Trace bitumen and coaly laminations (black layers), Middle Hibernia Formation. (40X Magnification)

Sandstone, medium to dark grey, trace pyrite, very fine grained to fine grained, non-parallel ‘banding’ (possible indications of post depositional movement during compaction). Trace bitumen and coaly laminations (black layers), Lower Hibernia Formation. (40X Magnification)

Sandstone, translucent to light grey to tan, microcrystalline to very fine grained with occasional medium grains, very hard, pervasive silica cement, tight.Catalina Formation. (40X Magnification)

Sandstone, translucent to light grey to white, poorly sorted, very fine grained to medium with occasional coarse grains. Coarse grains are highly rounded and polished (possibly aeolian, wind-blown) calcareous cement, tight, friable to hard. Catalina Formation. (40X Magnification)

Sandstone, translucent to light grey to off-white, microcrystalline in part to medium grained with occasional coarse grains, very hard, pervasive silica cement, tight. Catalina Formation. (40X Magnification)

Sandstone, translucent to light grey to white, microcrystalline to very fine grained with occasional medium grains of chert, cuttings are angular to sub-angular from impact with the drill bit. Very hard, pervasive silica cement, tight. (10X Magnification)

Limestone, light grey to dark tan, crypto-crystalline, dolomitic, angular fragments, hard. (10X Magnification)

Limestone shell fragments, laminated, well rounded. (10X Magnification)

Limestone, mottled, angular, hard. (10X Magnification)

Limestone, mottled, angular, hard. (10X Magnification)

Limestone, mottled, marly, soft. Petrel Formation. (10X Magnification)

Limestone, reddish, microcrystalline, angular, hard. (10X Magnification)

Limestone, light grey to white, silty and sandy, soft. (10X Magnification)

Siltstone, grey to dark grey with tints of green and pink, firm to soft, moderate swelling, moderately calcareous. (20X Magnification)

Shale, medium to dark grey, waxy lustre, wetted (40X Magnification)

Shale, grey green, light grey to grey with pinkish streaks, trace silty, firm to soft, slightly swelling, wetted. (20X Magnification)

Shale, dark grey with predominant pinkish streaks, firm to hard, waxy lustre, Medial Shale of the Hibernia Formation. (20X Magnification)

Shale, medium to light grey, firm to hard, trace to moderate calcareous cement. (20X Magnification)

Shale, medium to dark grey, firm to hard, trace calcareous cement, trace thin, white, crypto-crystalline limestone, non-swelling, wetted . (20X Magnification)

Shale, dark grey, hard, NOTE, elongate shape of cuttings (splintery) is possibly indicative of over-pressuring of the shale beds. (40X Magnification)

Shale, dark grey, trace brownish, hard, NOTE, elongate shape of cuttings (splintery) is possibly indicative of over-pressuring of the shale beds.Non-swelling, wetted. (40X Magnification)

Shale, dark grey associated with abundant siliceous flakes, very thin and brittle, possible slickensides associated with encountering a fault plane.(20X Magnification)

Siliceous flakes, very thin and brittle, possible slickensides associated with encountering a fault plane. (40X Magnification)

Limestone, light grey to tan, with Glauconitic inclusions, firm . (10X Magnification)

Limestone, light grey to white, with Glauconitic inclusions, firm.(20X Magnification)

Limestone, with Glauconitic inclusions, firm . (20X Magnification)

Sandstone, very coarse grained to pebbly with limestone matrix, friable. (10X Magnification)

Limestone, with sand and quartz pebbles, firm to soft . (40X Magnification)

Limestone, with sand and quartz pebbles, firm to hard, wetted .(20X Magnification)

Limestone, white, with well rounded, highly polished, varicolored quartz pebbles, firm to hard. (10X Magnification)

Limestone, white, with well rounded, highly polished, varicolored quartz pebbles, firm to hard. (40X Magnification)

Limestone, white, with well rounded, highly polished, varicolored quartz pebbles, firm to hard. (40X Magnification)

Quartz pebbles, well rounded, highly polished, varicolored, likely aeolian (wind blown) contained as inclusions in Limestone (previous slides). (20X Magnification)

Quartz pebbles, well rounded, highly polished, varicolored. The angular edges of this grain are a result of the grain being fractured by the bit.(40X Magnification)

Quartz and chert pebbles, well rounded, highly polished, varicolored, likely aeolian (wind blown) contained as inclusions in Limestone (previous slides). (40X Magnification)

Quartz and chert pebbles, well rounded, highly polished, varicolored, likely aeolian (wind blown) contained as inclusions in Limestone (previous slides). (40X Magnification)

Quartz and chert pebbles, well rounded, highly polished, varicolored, likely aeolian (wind blown) contained as inclusions in Limestone (previous slides).(40X Magnification)

Quartz pebbles, (chert) well rounded, highly polished, semi-spherical to spherical, occasionally elongate. (20X Magnification)

Quartz pebbles, white, well rounded, highly polished, spherical to sub-spherical, retrieved from predominantly soft, marly mudstone as likely wind-blown inclusions. (40X Magnification)

Crystals of Aragonite, replacing limestone from shell fragments. (10X Magnification)

Crystals of Aragonite, replacing limestone from shell fragments.(40X Magnification)

Quartz pebbles, white, well rounded, with pervasive pyrite as cement. (20X Magnification)

A ‘coaly’ fragment contained in Siltstone and Shale. Pyrite has replaced some of the original material. (20X Magnification)

A ‘coaly’ fragment contained in Siltstone and Shale. Pyrite has replaced some of the original material. (10X Magnification)

Woody fragment, pervasively replaced by Pyrite. (40X Magnification)

Woody fragments, occasionally coaly and pervasively replaced by Pyrite. (40X Magnification)