Material Balance Equation Templates
11 blueprints
Aquifer Model Matching
Estimate cumulative water influx using the Fetkovich aquifer model and match aquifer parameters (permeability, outer radius) to observed pressure-production data. The Fetkovich model uses a productivity index (J) and maximum encroachable water (Wei) to compute stepwise water influx.
Effective Compressibility Calculations
Calculate effective compressibility for different reservoir types. Effective compressibility is critical for material balance and pressure buildup analysis.
Fetkovich Aquifer Model
Calculate water influx using the Fetkovich pseudo-steady state aquifer model. This simplified approach treats the aquifer as a tank with a productivity index.
Gas Reservoir p/z Analysis
Perform p/z analysis for gas reservoirs to estimate OGIP (Original Gas in Place). The p/z vs Gp plot is linear for volumetric depletion, with x-intercept = OGIP.
Gas Reservoir Production Forecast
Forecast gas reservoir pressure and production using material balance equations. Given OGIP, predict pressure at future production levels or vice versa.
Geopressured Gas p/z Analysis
Compare standard vs modified p/z analysis for geopressured (abnormally pressured) gas reservoirs. Standard p/z overestimates OGIP because it ignores formation and water compressibility. The modified p/z method corrects for this, producing a straight line even for geopressured reservoirs.
Havlena-Odeh Oil MBE Analysis
Estimate OOIP and gas cap ratio for a saturated oil reservoir using the Havlena-Odeh straight-line method. Production history with PVT data at each pressure step are used to compute underground withdrawals (F) and expansion terms (Eo, Eg). Plotting F/Eo vs Eg/Eo yields a straight line whose intercept is N (OOIP) and slope is N·m.
Material Balance Expansion Terms
Calculate material balance expansion terms for oil reservoir analysis. These terms quantify fluid and rock expansion as pressure drops during production.
Reservoir Drive Mechanism Indices
Calculate drive mechanism indices to identify the dominant energy source driving oil production. Drive indices sum to 1.0 and indicate relative contribution of each mechanism.
Underground Withdrawal Calculation
Calculate underground withdrawal (F term) for material balance analysis. F represents total reservoir voidage from oil, gas, and water production.
Van Everdingen-Hurst Aquifer Model
Calculate water influx using the Van Everdingen-Hurst (VEH) transient aquifer model. This rigorous method handles both infinite and finite aquifers with time-dependent pressure response.