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