Motivation




Inputs & Outputs



InputsOutputs

Cumulative subsurface water influx from aquifer

initial formation pressure

Subsurface water flowrate from aquifer

aquifer Productivity Index





aquifer relaxation time



Detailing Inputs


aquifer Productivity Index

aquifer transmissibility

oil pay area

aquifer area

aquifer relaxation time

aquifer total compressibility

aquifer pore compressibility 

aquifer water compressibility

aquifer volume 

aquifer effective thickness

aquifer porosity



Assumptions



Const Productivity Index Aquifer




p_{AQ}(t) = p_i - \frac{Q_{AQ}(t)}{V_{AQ} \cdot c_t}




Equations



\frac{d Q^{\downarrow}_{AQ}}{dt} + \frac{1}{\tau} Q^{\downarrow}_{AQ} = J \cdot ( p_i - p(t))



q^{\downarrow}_{AQ}(t)=\frac{d Q^{\downarrow}_{AQ}}{dt} 



Assumption #1 = Const Productivity Index Aquifer:

q_{AQ} = \frac{d Q_{AQ}}{dt} = J_{AQ} \cdot ( p_{AQ}(t) - p(t))


Assumption #1 = Pseudo Steady State Flow:

p_{AQ}(t) = p_i - \frac{Q_{AQ}}{V_{AQ} c_t}


Eliminating one arrives to .


See Also


Petroleum Industry / Upstream / Subsurface E&P Disciplines / Field Study & Modelling / Aquifer Drive / Aquifer Drive @model

Reference


 1.   Fetkovich, M.J. 1971. A Simplified Approach to Water Influx Calculations—Finite Aquifer Systems. J Pet Technol 23 (7): 814–28. SPE-2603-PAhttp://dx.doi.org/10.2118/2603-PA