Oilfield depth question

11 March 2016, 04:11

I've always wondered about oil fields, so can someone here enlighten me about the depths of the oil?

This chart is one of many that has oil wells being about a mile deep:

https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm

My question has always been how did the oil get that far down? I have always thought that at one point in time way back when that was the ground level, and there has basically been a mile of sedimentation or subsidence/upheaval of one sort or other since the mesozoic age? I remember learning the Permian Basin sea was 500 meters in depth but do not know if that is relevant or not.

If one of you engineering/geologist types could post a brief reply on how it got so far down in would be greatly appreciated!

11 March 2016, 04:53

MikeBurke

I have asked the same question about oil in the Gulf of Mexico.

Shell's Perdido deepwater spar is receiving oil from wells in nearly 10,000 ft. of water.

IIRC those wells average around 10,000 deep.

Oil is coming to the surface from nearly 20,000 below.

Interesting to know how it got there.

11 March 2016, 05:36

J_Zola

My brother works for Nobel. It is amazing the amount of money that is spent in a day.

12 March 2016, 17:31

mete

It's the old demand thing .More demand and more is spent developing technology to go deeper. Here they drilled for ga in the Marcellus deposit . But then they found another larger deposit under that !! As Con-Edison said " Dig we must for [a growing demand ]

12 March 2016, 20:55

Mark

quote:
Originally posted by mete:
It's the old demand thing .More demand and more is spent developing technology to go deeper. Here they drilled for ga in the Marcellus deposit . But then they found another larger deposit under that !! As Con-Edison said " Dig we must for [a growing demand ]

My question is how do the oil deposits end up a mile or 3 below the present surface of the earth? It is not like it is a dense material and finds its own way down there, for the most part it appears to have been surface vegetation at some point in time which has apparently been covered up, correct?

I am trying to understand the geologic process responsible for covering the top of these huge deposits with miles of earth. Windblown? Marine sedimentation? Geologic shifting?

14 March 2016, 17:48

Jim Kobe

How about this one: how did the coal get under the antarctic ice cap? I have also wonderd about the the oil.

14 March 2016, 20:22

eny

You'v got to get your head wrapped around what can happen geologically in more than 100 million years.

14 March 2016, 21:13

MikeBurke

I suppose it is similar to finding marine fossils at over 4000 ft. elevation near the Grand Canyon.

14 March 2016, 23:20

eny

Fossils begin to appear from over 3 billion years ago, can pile a lot of stuff up in that amount of time

15 March 2016, 02:58

MikeBurke

The marine fossils in the Grand Canyon were deposited when that area was underwater and there were shifts in the earth's plates and caused that area to rise, or at least something like that or so I was told by the tour guide.

17 March 2016, 02:22

Mark

quote:
Originally posted by Jim Kobe:
How about this one: how did the coal get under the antarctic ice cap? I have also wonderd about the the oil.

Here's another one far as wacky geologic phenomena goes, Mauna Kea was covered by glaciers at one time too.:

http://hvo.wr.usgs.gov/volcano...e/2007/07_10_18.html

Geologists have identified three periods when mountain glaciers covered the summit region. Glacial moraines formed about 70,000 years ago, and younger ones were deposited approximately 40,000 to 13,000 years ago by a more recent ice cap. It has been estimated that glaciers on Mauna Kea had an average thickness of 100 m (330 ft) and could have attained a thickness of 170 m (560 ft). They covered an area of more than 70 km2 (27 sq. mi.).

17 March 2016, 02:40

vashper

Due to the tectonic activity of the mountain is constantly growing, and due to the effect of the atmosphere is constantly being destroyed, forming sedimentary rocks. These sedimentary rocks poured oil-bearing strata in depressions of continental plates and between them. This theory is based on the hypothesis of a biological origin of petroleum, like coal or peat. There are other hypotheses suggesting that the hydrocarbons - the primary substance found in the earth's crust from the time of creation, just closer to the surface they disappeared.

17 March 2016, 04:27

Kensco

Damn Vashper, you're scaring me now. Sounds like that question dropped right into your wheelhouse. What gives you the right to sound like a college professor? I thought you were just a good-old-boy I would enjoy having a drink with. Now I've got to go back to school and get another degree just to stay in the same room with you.

17 March 2016, 05:47

dukxdog

I've drilled wells from 3,000' down to over 27,500' in Wyoming. I've drilled with air, water based mud and inverted mud.
I've worked on rigs in the "Overthrust Belt" in western Wyoming where formations are turned over upon themselves. Makes for interesting drilling and soil samples.
I have my own theories about "fossil" fuels.

20 March 2016, 05:44

Kensco

I didn't know Wyoming went that deep. Was TVD like 24k to 26k? The last I saw, the deepest dry hole in Wyoming was 25,700+, and deepest producer was a gas well at 24,877'.

I hadn't thought about air drilling in a long time. We had six sets of compressors sitting behind our rigs down in the Sonora-Ozona area. A lot of fun.

We tried air in places in New Mexico that never should have been tried.

Those were the days; mud rings, burn-offs, aluminum drill pipe, square drill collars.

Had the pleasure of learning from one of the pioneers; "Mule" Payne, with Dresser at the time.

24 March 2016, 22:26

stradling

it starts with carbon sunlight and fat

the pre salt of brazil and angola are good deep oil examples

continental plate drift--ocean floor spreading --deep time --green oceans [[then]]

stratigraphic traps-- source rock --reservoir rock-- cap rock

all parts of the oil story

it's all about little green ''bugs'' plants

watch this utube story on crude it's worth the time
https://www.youtube.com/watch?...l0eWf-7oAlniHoxPcvLg

https://www.youtube.com/watch?v=e44ydPIQGSc this one has a climate change bend but some good in there about oil

26 March 2016, 03:03

vashper

Don't even know what to say.... this "Physical geography" for 6 th grade... but I can reassure you: we are moving now to Western standards of education. And then, do you think that University professors do not drink? Greatly mistaken.

26 March 2016, 05:35

Kensco

I grew-up in a university town, and my dad had many college professor friends. Very strange group.

One was a math whiz and got banned from Las Vegas for counting cards and winning big. (He appeared on the TV program What's My Line.)

The dean of mechanical engineering was responsible for my career in engineering because one day he stopped me and said, "why don't you be an engineer". I didn't have an alternative in mind so I did.

The dean of the math department lived next door. He and his math pals used to have drinking parties and have farting contests that they taped (reel-to-reel, and played back at high volume. As a young teenager I thought that was funny as Hell. You could here the tape two houses down.

That same math dean had been a bomber pilot in WWII and participated in the fire-bombing of Dresden, Germany. The professor of physics who lived across the street was German. He was in Dresden during the fire-bombing. Talk about two guys that hated each other.

30 March 2016, 23:42

TomP

quote:
Originally posted by dukxdog:
I've drilled wells from 3,000' down to over 27,500' in Wyoming. I've drilled with air, water based mud and inverted mud.
I've worked on rigs in the "Overthrust Belt" in western Wyoming where formations are turned over upon themselves. Makes for interesting drilling and soil samples.
I have my own theories about "fossil" fuels.

I spent some of a morning yakking with drillers at the Pinedale Anticline, they said most of their holes were about 19,000 feet. What did you find at 27,500 deet?

31 March 2016, 02:45

MikeBurke

In the Gulf of Mexico they have found huge gas reserves at nearly 30,000 ft. with bottom hole pressures over 20,000 PSI. Some have been problematic to complete and produce.

31 March 2016, 20:41

TomP

quote:
Originally posted by MikeBurke:
In the Gulf of Mexico they have found huge gas reserves at nearly 30,000 ft. with bottom hole pressures over 20,000 PSI. Some have been problematic to complete and produce.

I remember reading that the Macondo well had bottom pressures about like a black-powder Colt's chamber pressure.

01 April 2016, 00:15

vashper

I read recently about the origin of kimberlite pipes. These causes are still unknown, because it is impossible to imagine the physics of the process, which pierces the continental platform as the needle. But, it seems, with the further development of ultra-deep drilling, we will see artificial kimberlite pipe.

02 April 2016, 06:32

Kensco

I think the Macondo BHP was around 12,000 psi. The Macondo well design is here

http://www.nap.edu/read/13273/chapter/5

Like most offshore, deep wells, the problems are complex, the dangers are immense, and the margin for error is very small. While drilling, the difference between a kick (flow) and formation fracture was a mud weight of .2 pounds per gallon at Macondo.

An incorrect interpretation of a pressure test started things going the other way.

Every deep well into high pressures run the risk daily of a kick. I was glad to retire before one bit me in the a$$. Plenty kicked, but only one got away, a land job, way back in the early 80s west of Eunice, New Mexico. Why it didn't catch fire and burn the rig down I'll never understand.

The guys on all rigs, both for the Operator and the Drilling Contractor are heroes, particularly when you're out there in open water a couple hundred miles from shore. They do some amazing work that for the most part goes unrecognized.......until something goes wrong.

02 April 2016, 16:44

DenisB

Thanks gents for the links
that was interesting.

09 April 2016, 20:10

TomP

quote:
Originally posted by Kensco:
I think the Macondo BHP was around 12,000 psi. The Macondo well design is here

http://www.nap.edu/read/13273/chapter/5

Like most offshore, deep wells, the problems are complex, the dangers are immense, and the margin for error is very small. While drilling, the difference between a kick (flow) and formation fracture was a mud weight of .2 pounds per gallon at Macondo.

An incorrect interpretation of a pressure test started things going the other way.

Every deep well into high pressures run the risk daily of a kick. I was glad to retire before one bit me in the a$$. Plenty kicked, but only one got away, a land job, way back in the early 80s west of Eunice, New Mexico. Why it didn't catch fire and burn the rig down I'll never understand.

The guys on all rigs, both for the Operator and the Drilling Contractor are heroes, particularly when you're out there in open water a couple hundred miles from shore. They do some amazing work that for the most part goes unrecognized.......until something goes wrong.

On the mud weight problem, a friend and I wrote up a proposal to try plugging it with a low-melting alloy with a specific gravity of about 9, with the idea that it would remain liquid to the bottom with the prevailing temperatures. We figured it would take about 200 tons to do the deed. Was the bottom hole small enough for that to plug the pipe, or would more likely just run out the bottom?

11 April 2016, 05:46

Kensco

Not my area of expertise. Can't say. Interesting idea though.

One thing for sure, since the blowout was in the annulus and not back through the pipe, plugging the drill pipe wouldn't have solved the problem.

Once they sheared the drill pipe, there would be no way to get anything to bottom. When you activate the blind-shears it is basically ballgame-over. The BOPs better hold. If they don't, you have Macondo. They didn't hold.

Can't second-guess anyone. I wasn't there.

11 April 2016, 20:48

Gatogordo

quote:
Can't second-guess anyone. I wasn't there.

Well done. You're one of the few, most of the critics wouldn't know what a BOP was until they read about one.

From Teddy Roosevelt:

xxxxxxxxxx
When considering US based operations of guides/outfitters, check and see if they are NRA members. If not, why support someone who doesn't support us? Consider spending your money elsewhere.

NEVER, EVER book a hunt with BLAIR WORLDWIDE HUNTING or JEFF BLAIR.

I have come to understand that in hunting, the goal is not the goal but the process.

11 April 2016, 20:54

Gatogordo

Or, put in a similar manner by Domingo Ortega, the great matador in 1962:

quote:
Bullfight critics ranked in rows
Crowd the enormous Plaza full;
But he’s the only one who knows—
And he’s the man who fights the bull.

13 April 2016, 03:32

Kensco

In offshore drilling you were constantly fighting the bull, or the bullshit.

There was a direct correlation between distance and bravery. The people back in town or halfway around the world; the farthest from ground-zero, were always the "bravest".

You always wanted someone on the other end of the phone to have been there before; stared-down the bull. Otherwise you were on your own.

I worked for some good ones, and I worked for some that you had to ignore, and hope you came out the other side of the tunnel. Otherwise, you knew you were going to be looking at the underside of the bus.