8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 1/16

Navneet sharma

B.Tech (APE-II)R040307031

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 2/16

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 3/16

Potential additions to HC reserves come from two sources

New discoveries, and

Existing fields

The ratio of discovery rate to consuming rate is one to fourbarrel of conventional oil, thus, the gap between discovery and consumption is big and may grow.

Therefore, we should focus on the existing wells,

including stripper wells.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 4/16

W e are going for heavy oil because conventional oil isdrying up.

There is approx 6-9 trillion bbl of heavy oil in theworld in form of bitumen, Tar sands.

Since, current total world demand for oil is in therange of 30 billion bbl per year with heavy oil we are

talking about 200-300 yrs worth of potential supply.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 5/16

Definition of Heavy Oil 

Heavy crude oil or extra heavy crude oil

is any type of crude oil which does not floweasily.

It is referred to as "heavy" because its

density or specific gravity is higher.

Heavy crude oil has been defined as any liquid petroleumwith an API gravity less than 20°, meaning that its specificgravity is greater than 0.933.

This mostly results from crude oil getting degraded by beingexposed to bacteria, water or air resulting in the loss of itslighter fractions while leaving behind its heavier fractions.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 6/16

More about Heavy oil

In contrast, heavy oils typically have both a low APIgravity and high viscosity, such that they do not flow

naturally.

Production, transportation, and refining of heavy crude oil present special challenges compared to light

crude oil.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 7/16

Steam injection is an increasingly common method of extracting heavy oil.

It is considered an Enhanced oil recovery (EOR) methodand is the main type of thermal stimulation of oilreservoirs.

Most commonly applied to oil reservoirs which arerelatively shallow and which contain crude oils which arevery viscous at the temperature of the native undergroundformation.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 8/16

The main benefit comes

from a large reduction in

the oil viscosity with

increased temperature.

Large pressure gradients

also help mobilize oil.

Lower interfacial tension ,

but it is secondary.

0.1

1

10

100

1000

100 1000

Temperature (F)

 

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 9/16

I. Cyclic steam stimulation.

II. Steam flooding.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 10/16

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 11/16

It is also known as Huff and Puff method, it consists of 3 stages:-

1. Injection steam is injected for certain amount of time.

2. Soaking steam injected is left for few days.

3. Production- oil is produced from the same well, since steaminjection will increase reservoir pressure and decreases S.G.And make it less viscous to flow naturally.

Production decreases as oil cools down and cycle is repeatedagain when it reaches below economic limit.

Recovery is approx only 20% of the original oil in place .

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 12/16

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 13/16

It is also known as steam drive, in this some wells act asinjection wells some acts as production wells.

Two mechanisms are involved in this :

1. First to heat the oil to higher temperature and then tothereby decrease its viscosity so that it more easily flows through the formation toward the producingwells.

2. Second is the physical displacement of oil pushed tothe production wells.

More steam is needed than the cyclic method.

Recovery is 50% of OOIP.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 14/16

Cyclic steam stimulation

oRecovery conformance along length of horizontalwell bore .

oW ell bore casing design due to high operatingtemperature and pressure.

Steam drive stimulation

oRadial distribution of steam to mobilize bitumen.

oEffect of free water within formation on recovery andprocess efficiency.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 15/16

R ecovery of heavy oil by steam flooding combined with a nitrogen drive

�It decreases the cost of production of each barrel of oil because the cost of generating nitrogen used for f looding the formation in the present invention isonly one-third of the price for steam generation.�Also, the use of nitrogen can also prevent formation damage, well corrosion etc.

Liquid addition to steam for enhancing recovery of cyclic steamstimulation or LASER-CSS 

�It consists of mixing liquid hydrocarbons into the injected steam instead of injecting such hydrocarbon as a separate slug in front of a steam stimulationcycle.�The objective of this invention is to enhance field applications of Cyclic SteamStimulation (CSS) by contacting and mobilizing more of the bitumen with thesame amount of steam.

8/7/2019 Recovery of Heavy Oil by

http://slidepdf.com/reader/full/recovery-of-heavy-oil-by 16/16