Water influx Carter-Tracy Model

 This method is an approximate solution to the diffusivity equation. It can be

combined conveniently with a suitable material balance equation to predict the

performance of water-drive reservoirs. The Carter-Tracy aquifer models can be

applied to both finite and infinite-acting aquifers. It can be applied to both radial

and linear aquifers and also applies to edge-water drive reservoirs only. Mathemat￾ically, 

it is calculated as

Steps in Calculating Carter-Tracy’s Aquifer Model

Step 1: Calculate the total pressure drop at each time step

Step 2: Calculate the dimensionless time at each time step

Step 3: Calculate the dimensionless pressure and pressure derivative at each time

step

Step 4: Calculate the water influx at each time step (Table 4.8)

Table 4.8 Carter-Tracy aquifer model calculation

Example 4.5

Repeat Example 4.3 using the Carter Tracy’s aquifer model to calculate the cumu￾lative water influx at each time step.