Category: The General Material Balance Equation

As early as 1953, van Everdingen, Timmerman, and McMahon recognized a method of applying the material balance equation as a straight line.9 But it wasn’t until Havlena and Odeh published their work that the method became fully exploited.3,4 Normally, when using the material balance equation, an engineer considers each pressure and the corresponding production data as being separate…

The material balance equation derived in the previous section has been in general use for many years, mainly for the following: 1. Determining the initial hydrocarbon in place 2. Calculating water influx 3. Predicting reservoir pressures Although in some cases it is possible to solve simultaneously to find the initial hydrocarbon and the water influx, generally one or…

When an oil and gas reservoir is tapped with wells, oil and gas, and frequently some water, are produced, thereby reducing the reservoir pressure and causing the remaining oil and gas to expand to fill the space vacated by the fluids removed. When the oil- and gas-bearing strata are hydraulically connected with water-bearing strata (aquifers) with…

Fluid does not leave a void space behind, as it is produced from a hydrocarbon reservoir. As the pressure in the reservoir drops during the production of fluids, the remaining fluids and/or reservoir rock expand or nearby water encroaches to fill the space created by any produced fluids. The volume of oil produced on the…