modified June 10-2015
The following accounts (from Presho 2 by S. Chadima) are for the purpose of project coordination only. They are preliminary and will probably be revised as more information is received and analyses prepared. They should not be quoted at the present time.
Presho2
The term "Oil" in the following notes may or may not be oil in the proper sense - it was liquid and black, felt oily, and it was lighter in density, floating on top of the water. Even though light in density, at times it became thick and somewhat viscous. Depths are based on drill rods in the hole and are, therefore, only approximate.
2. Bubbles
and foam at 491.5ft, all gone by 493ft.
3. Bubbles at
496ft, gone by 498ft.
4. Bubbles at
522ft, no foam, disappeared by 524ft.
5. Bubbles at
526ft, no foam. I drove to town so don't know when the bubbles stopped.
6. Bubbles at
532ft, no foam. Likely gone by 534ft.
7. Ted
noticed a tiny amount of an oil sheen at 538ft, by the time I got over to the
mud pit I couldn't see it. But there were a few bubbles, fine/small, very few
compared with earlier shows.
8. Cleaning
the hole of weekend buildup on Monday 4-27, we got bubbles (repeat depths as we
saw the previous week) at 496 and 526 feet.
9. Bubbles at
541ft, with a hint of thin foam. The bubbles didn't have much omph, and they all
popped quickly/never made it past the first compartment of the mud pit.
10. Going back
downhole after overnight, on Tuesday 4-28, we had a few bubbles at 543.5ft.
11. The first
pass then of that day (544-548ft), we encountered bubbles at 544.5ft.
12. Tiny
bubbles at 577-578ft. If you put your ear down by the mud pit you could actually
hear them fizz (pop)! We tried to collect a water sample, with bubbles. Maybe
the gas can be analyzed?
13. Oil at
585ft 2inches. Collected a sample in a Gatorade bottle. At the end of the pass,
589-594ft, after the core was out of the hole, more oil came up in the pit.
14. Hint of
oil at 599ft, also a very few/rare gas bubbles.
15. While
putting rods down first thing in the morning, before pass 604-609ft, oil kept
coming up. Assuming we were jarring/bumping something at some depth. I collected
a zip lock bag full of this oil and gas. While drilling this entire pass, we had
an oil sheen in the mud pit the entire time. There were a few gas bubbles. At
608ft, there were larger clumps of bubbles (like grape clusters). Bubbles were
oil-coated, and persisted in the hand-held colander/screen.
16. Pass 609-
614ft had a thin oil show from 609- 612ft. Gas was thicker in the last 2 feet,
with small grape cluster-like clumping.
17. Pass 29
(614-619ft), oil but no gas as we began to core. At 617ft, thicker oil with tiny
gas bubbles. Collected in another ziploc bag using the sieve/colander to help
concentrate the oil, and allow the water to drain away. At 618.5ft, thicker oil,
photos of oil coated gas bubbles popping in the handheld sieve. It poured from
the sieve with a viscosity like chocolate pudding.
18. Lots of
thicker oil from 619-620ft, with some bubbles.
19. Possible
kp/kn contact at 626ft, as core became calcareous.
20. Bubbles
and slight oil at 635ft. This was the first pass of the day. (A consideration,
maybe we disturbed something uphole?) But we had oil during the rest of the pass
(pass 33, 634-638ft 2 inches), notably so at 637ft. Took a sample as it seemed
more olive in color.
21. Gas
bubbles at 708ft.
22. Gas
bubbles at 722ft.
Note - I never
found a correlation anywhere in the core, where oil was "oozing" or even
present as a coating within/on/from the rock core.
--------------- WMR notes that the occurrence at 486 may come from a horizontal fracture in a shell bed that appeared to be substantially more brittle than the shale above and below. Refer to pictures for this section.