All language subtitles for ch2 p2

Since organic material was created in hundreds of

locations throughout the earth's surface at

different times in different circumstances we get

different types of oils.

In areas where the organic material wasn't buried as

deep in areas that were more shell and were buried for

a short time we get heavier tar like oil.

If the organic material was buried really deep a

couple of thousand meters or so we get more cooking

more died jannik effect and we get lighter low

viscosity isles.

In organic materials that were buried more than six

thousand meters deep and for very long times we get

only guess.

At that depth the temperatures and pressures have

destroyed or broken apart the molecules so that

eventually only the small hydrocarbon chains of

methane are left.

Oil is found and reservoir rock so let's turn our

attention to what a reservoir is.

In their sexual talk about reservoir rock

properties rock properties are things like type of

rock the percent of oil in iraq and the ability of that oil.

The flow out our through that right rock.

In the u a e the most common reservoir rock he is limestone.

But the other common reservoir rocks are sandstone

and dolomite would your phone commonly in many

places throughout the planet.

Oil sits inside these reservoir rocks.

If you look at a piece of limestone or sandstone or

dolomite with a magnifying glass you will see little

pores are whole that run through the rock.

It is in these holes at the fluid oil or gas or water accumulate.

The rock must contain some open spaces within the

structure of the rock to hold fluid.

The number and size of these holes within the rock

determines it's prosody or poor space.

We measure the prosody by the percent of space that is

open compared to the space that is closed.

If you have a prosody of one hundred percent you have

pure fluid.

You have fluid and know rock.

Now if you have zero percent prosody you have pure

rock and know fluid.

Igneous rock.

Or some minerals like diamonds are good examples of

zero prosody.

They have no holes in their structure.

A meaningful prosody where oil is retrievable is in

the five to thirty percent.

A range.

Of course bigger prosody percentage implies more fluid.

Oil is found in sandstone and limestone but it also

can be found and shale.

But shell has a prosody of about one percent so the oil

is very difficult to get out.

Basement rock.

Is either igneous or metamorphic rock and contains

no oil.

So if you are drilling and you hit basement rock you

are done drilling.

Crude is found in reservoirs not in underground

lakes or pools but didn't hold in the reservoir rock.

These holes or call prosody and it's symbol is fi.

Here is a drawing with perfectly spherical

settlement particles.

All the same size laid down symmetrically see you get

this year no form space between the particles.

Which would equal in this example above forty eight percent.

That is the maximum amount of prosody and any

reservoir rock.

Remember though that this is theoretical only in the

real world where nothing is truly spherical or uniform.

You would get less ferocity.

Sedimentary rock is made up of the accumulated

sentiment particles that have been squeezed and

heated deep underground.

If the grains of sand in sandstone.

Our well sorted and rounded they will have a prosody

of about twenty five percent.

This type of prosody would probably find in the

remains of.

Ancient beaches because the waves pound the

particles until the sand is ground down into uniform

grains and are all about the same size when sands

contain grains that are various sizes and shapes all

within the say reservoir rock.

We say that it is a poorly sorted rock.

These various shapes can decrease the perasa the of

the rock because there is less poor space and a

typical per se for this type of accumulation isn't

that five to fifteen percent range.

A geologist job is to note these types of rocks and

report is findings because an estimating the flow

rate of a well it is vital that the petroleum engineer

understands the per our city of the reservoir iraq.

In this next example you can see where the particles

look like they have been cemented together.

Cementing in nature is caused when sedimentary

clay's get wet and a chemical reaction takes place.

Literally cementing these rocks and place.

Of course cementing will decrease prosody because

this amending seals off the spaces between the rocks

reducing poor space.

And not allowing any liquid to accumulate.

So far we have been talking about into granular

prosody or poor space between the greens.

There is another type of prosody called vogler prosody.

This is where holes in the rocker formed.

These holes are typically found in limestone reservoirs.

Where do the holes originally come from and limestone.

Well after little vacation or rock formation the

limestone may have been lifted above the ocean level

and exposed to fresh surface water.

This lifting can be caused by things like

earthquakes or plate movements.

Fresh water like rain can mix with atmospheric c o two

causing carbonic acid.

This acid water percolate slowly through the

limestone and dissolves channels causing anywhere

from large chambers and caves.

To tiny interconnected networks of holes.

Poor space cavities can be seen in this diagram

amplified by the green color.

This prosody is called vogler prosody.

The third type of prosody is called fracture or prosody.

This is where the prosody is caused by fractures.

Where the rock actually breaks apart into cracks.

These cracks contribute to the formation prosody by

increasing the poor space.

In fact a technique in completion of an oil well is to

pump down acid under very high pressure to help

create these cracks.

This is called well stimulation.

So let's review there are three types of prosody.

One into granular prosody where the prosody is

caused by the spaces in between the grains.

To vogel are prosody where the prosody is caused by

holes that form in the rock.

And number three for actual prosody where the

prosody is created by fractures or large cracks in

the reservoir rocks.

Now in order to be a good reservoir rock you need the

following characteristics number one porous rock

rock that is filled with empty space containing fluid.

Number two permeability the rock prosody must be

connected channels between the poor spaces for the

fluid to flown we need fluids to be able to flow.

Even though there might be holes or prosody in the

rock these holes must be connected.

They must have little channels between them.

We measure permeability in the laboratory using

rock core samples.

The unit of measurement four per ability is called

the millie darcy or m d.