MatBal^® Software Technology

MatBal software allows the user to model multiple reservoir and aquifer systems, with inter-reservoir, inter-aquifer and reservoir-aquifer fluid flow. Wells can be completed in more than one reservoir, allowing for cross flow via the wellbore.

Reservoir Data

The MatBal application can model the following types of reservoir:

• Oil (with or without gas-cap)
• Condensate (with or without oil rim)
• Dry or wet gas
• Volatile oil

Injection of water and/or gas is allowed. Reservoir-reservoir pressure communication is modeled by transmissibilities. Formation compressibilities are entered either as single values or as functions of pressure.

PVT

Tabular PVT data is used for each reservoir. For volatile oil and gas-condensate reservoirs a modified black-oil model (i.e. vaporized condensate in gas-phase) is used for a more accurate representation of phase changes. Links to WellFlo^® software allow the PVT data to be imported from tuned black-oil correlations.

Aquifer Models

The program’s aquifer models range from simple pot aquifers to line, bottom and flank geometries for which the following type of aquifer solution methods are available.

• Fetkovitch
• Modified Fetkovitch
• Carter-Tracey
• Hurst and Van Everdingen
• Model building

Well Models

The MatBal well model is based on parameterized inflow performance relationships (including straight-line, Vogel and normalized pseudo-pressure) and tubing performance characterized by vertical flow performance (VFP) tables. Both the inflow performance and the VFP data can be generated directly from WellFlo software and imported into the program. It is possible to enter pseudo-relative permeability curves (parameterized by Corey functions) for wells to predict water cut/WGR and producing GOR/CGR development as a function of average phase saturations. Regression facilities exist within the software to tune the well‑reservoir model to historical water cut/WGR and GOR/CGR evolution.

Individual well constraints such as maximum water cut, maximum drawdown or maximum rate can also be specified.