dissolved gas drive
TRANSCRIPT
By-Aashutosh Gautam(01) Abhilasha Singh(02) Aditi jayaraj(03) Aditya B. Bhatnagar(04) Ajay dalal(05) Animesh Chaudhury(14)
Reservoir Drive Mechanism 1
What is Reservoir drives? Types of reservoir drives Dissolved gas drive Gas cap drive
Reservoir Drive Mechanism 2
What causes hydrocarbons in the reservoir to move to the wellbore ?
Which forces should be supported or pushed back ?
Where and how should secondary recovery strategies be implemented?
Reservoir Drive Mechanism 3
Pressure on the fluids in a reservoir rock causes the fluids to flow through the pores into the well.
This energy that drives the oil and gas is called the reservoir drive or reservoir energy.
This energy comes from fluid expansion,rock expansion and gravity.
Reservoir Drive Mechanism 4
1. Dissolved Gas drive
2. Gas Cap Drive
3. Water Drive
4. Gravity Drainage
5. Combination Drive
Reservoir Drive Mechanism 5
Also known as solution-gas or depletion drive.
Natural gas is dissolved in oil in reservoir under high pressure
When well is drilled,pressure decreses Gas bubble out of the oil forcing oil to
move through the rock into the well
Reservoir Drive Mechanism 6
The recovery efficiency is 5 to 30%. Natural gas is dissolved at subsurface
pressure in the reservoir. When oil is produced from the reservoir,
reservoir pressure decreases and dissolved gas bubbles out.
The gas expands in the pore spaces and pushes the reservoir oil through the pore to a production well.
Reservoir Drive Mechanism 7
During the producing life of a dissolved gas pool a time comes when the reservoir pressure is reduced to the saturation pressure and free gas comes out
The free gas continues to accumulate at the top of the reservoir and become a secondary free gas cap.
As the pressure gradient decreases the free gas comes out continuously and forms a gas expansion pool.
Reservoir Drive Mechanism 8
As secondary gas cap is formed it develops a high gas oil ratio
The reservoir energy may be renewed by injecting gas under pressure into the reservoir through neighboring intake wells
The process of maintaining the reservoir pressure near its original height through the injection of free gas into the reservoir is called pressure maintenance or repressuring
Reservoir Drive Mechanism 9
The pressure is also maintained through the injection of water under pressure is called water flooding
The production mechanics that govern oil production from a natural Dissolved-gas drive and from an artificial or repressurred gas drive are similar
Reservoir Drive Mechanism 10
Reservoir Drive Mechanism 11
Reservoir Drive Mechanism 12
Reservoir pressure Surface gas-oil ratio Water production Well behavior Expected oil recovery
Reservoir Drive Mechanism 13
THANK YOU
Reservoir Drive Mechanism 14