Explanation of reservoir related term

[pet_spec]

Hello,

can you please help me to interpret the following :

"With steady state flow, the drawdown, the average reservoir pressure and flowing bottomhole pressure stays constant as influx into the drainage area equals the voidage"

What contextual meaning the word "voidage " carries here?

Thanks.

[Yengineer]

Lets say you have a reservir and are producing q=1000bbl/day from it. Now lets say the reservoir is conncted or it has an aquifer or you are simply injecting into it an amount of I=1000bbl/day. Since the voidage rate q = I (influx) you have a steady state.

[pet_spec]

Thanks mate. You made it clear for me.

[vinomarky]

The use of the work voidage is commonly used to make clear that they mean volumes at RESERVOIR CONDITIONS

As an example, if you are producing oil with Bo = 1.3 at 1,000 stb oil/day, then there would have to be 1,300 reservoir barrels of replacement per day

[DAH7542]

The qualitative concept of "Voidage" has been made clear now. In its simple mathematical form, the total reservoir voidage, i.e. the sum of oil, water and gas flows at reservoir conditions is defined as:

Total Reservoir Voidage = qo*Bo + qw*Bw + (GOR-Rs)qo*Bg