Brown 1 np

Question 1

What is PI?

Answer 1

PI is defined as barrels of total production (oil+water) per day per psi of pressure drop (Pr - Pwf (average static wellbore pressure - flowing wellbore pressure)). It is the first differential of IPR in case it’s a straight line.

Question 2

What is IPR?

Answer 2

The relationship between flowing pressure and rate.

Question 3

What is the typical performance of a solution gas drive?

Answer 3

Rapid decline in pressure, the rapid decline in PI and the increase in the gas-oil ratio. In general, expect to be low rate producers in their latter life (less than 100 bpd mostly)

Question 4

Is it a good idea to create an excessive drawdown in a depletion drive reservoir?

Answer 4

It will result in an increased gas phase in the reservoir - an increased permeability to gas and decreased permeability to oil.

Question 5

What are water drive characteristics? What is going on with the pressure and stuff?

Answer 5

Well, probably the optimum rate of production. Pressure may remain constant, PI remains constant over the life of the well, GOR is the same. But increase in water-cut causes a decrease in PI.

Question 6

What specific PI is?

Answer 6

It is the productivity index divided by the net feet of pay, or aggregate thickness of rock, that gives us fluids for commercial usage.

Question 7

Will PI increase or decrease for an increasing rate?

Answer 7

Decrease. PI = J = - (dq/dpwf)