unconventional exploitation of oilgas a study on fractured shale

7/31/2019 Unconventional Exploitation of Oilgas a Study on Fractured Shale

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UNCONVENTIONAL EXPLOITATION OF

OIL/GAS: A STUDY ON FRACTURED

SHALE

UNDER THE GUIDANCE OF:

DR.K.C.MATHUR


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It has taken between 50-

300 million to form, and

yet we have managed to

burn roughly half of all

global oil reserves in

merely 125 years or so.

The world now consumes

80-82 million barrels of

oil per day, or 40,000

gallons per second, and

demand is growing

exponentially


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By 2030 ,theoil productionwill startdecreasing


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A petroleum reservoir, or oil and gas reservoir, is a

subsurface pool of hydrocarbons contained in porous

or fractured rock formations. The naturally occurring

hydrocarbons, such as crude oilor natural gas, are

trapped by overlying rock formations with lower

permeability.
http://en.wikipedia.org/wiki/Crude_oilhttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Natural_gashttp://en.wikipedia.org/wiki/Crude_oil


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The unconventional resources usually refer to ultra low

permeability reservoirs that cannot be produced at economic rates or

volumes without stimulation of near well-bore regions.

New technologies of horizontal well coupled with staged hydraulic

fracturing have made the development of these reservoirs an

economic reality .

Moreover presence of natural fractures that are possibly connected

through the horizontal wells and the hydraulic fractures and makes

the subject matter for the present study


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Better reservoir knowledge

increasingly sophisticated technologies ,make the production

of unconventional resources economically viable and moreefficient.

This efficiency is bringing

shale reservoirs tight gas and oil

coalbed methane ,into the reach of more companies around

the world.


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Shale is a fine-grained sedimentary rock that

forms from the compaction of silt and clay-size mineral particles that we commonly call

"mud". This composition places shale in a

category of sedimentary rocks known as

"mudstones".

Shale is distinguished from other mudstones

because it is fissile and laminated. "Laminated" means that the rock is made up

of many thin layers.

"Fissile" means that the rock readily splits

into thin pieces along the laminations.

Black organic shales are the source rock formany of the world's most important oil and

natural gas deposits.
http://geology.com/oil-and-gas/http://geology.com/oil-and-gas/http://geology.com/oil-and-gas/http://geology.com/oil-and-gas/


8/17

Shale Gas:

Natural gas is found in shale. Shale gas is considered anunconventional source of natural gas, in that the methods used toextract it are not the same as conventional gas recovery.

Shale gas, with estimated global, technically recoverable reserves of6600 trillion cubic feet has the potential to make several countries,including the U.S., energy independent. In fact, shale gas, onceunrecoverable, now accounts for over 30% of U.S. natural gas

production.

The Barnett Shale of Texas was the first major natural gas fielddeveloped in a shale reservoir rock. Producing gas from the BarnettShale was a challenge. The pore spaces in shale are so tiny that the gas

has difficulty moving through the shale & into the well.


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Graph or data???


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There is much confusion about the terms shale oil and oil

shale. The two are often used interchangeably, but, in fact are

very different.

Oil shale is an organic-rich sedimentary rock that

contains kerogen. Kerogen-rich rock must be heatedat extremely high temperatures (500 degrees Celsius)

in order to process it into liquid oil.

Shale oil on the other hand, is oil produced directly

from shale reservoirs. Shale oil does not have to be

heated in order to flow into a well.


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Shale oil, with estimated global reserves of 2.9trillion barrels, holds huge promise as anemerging energy supply.

But the technical challenges posed by shale

play composition, location and extractionmethods require:

a great deal of innovation

robust global energy pricesin order to make production financiallyfeasible.


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The multistage hydraulic fracturingstimulates the reservoir effectively with anengineered solution.

Implementation of massive multi-stagehydraulic fracturing (MMHF) in longhorizontal wells has changed the natural gasindustry worldwide


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Indrora Pay Shale reservoirs are so called unconventional fractured shalereservoirs due to their low permeability characteristics.

Indrora Pay Shale reservoir is characterized by high pressure to the order of 30-

60% more than hydrostatic (232kg/cm2 at 1460m in Ind-1 during 1971,169.7kg/cm2 at 1460m in 1991)) as is evident from continuous gas and oil showswhile drilling through this section and recorded pressures in drilled wells.

However, the formation pressure has declined from original more than 60% thanhydrostatic to present 20-30% more than hydrostatic based on the recently drilledwell data on Ind-11.

High pressure in these shales is caused diagenetically by conversion of clayminerals like montmorillonite into illite, which release water and exert overpressure.


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Paleozoic Devonian and Mississippi shales of USA,

especially Barnett Shales of Fort Worth Basin, North

Central Texas are most active gas plays at present.

However, Brown Shales and Antelope shales of san

Joaquin valley are oil producing analogs to Indrora

shales. Overall, USA shale reservoirs are dominantlygas producer while Indrora shale reservoirs are

dominant oil producers


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PREPARED BY:DIVYA SHARMA

R040208012

PRASHANT TIWARIR040208026

unconventional exploitation of oilgas a study on fractured shale

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