Curving G-function plots and picking closure
![G-function plot of a typical DFIT.](https://www.resfrac.com/wp-content/uploads/2019/07/da1386_57969f364a7c41c28d79ee4b1315dce8mv2.png)
G-function plots are routinely used to interpret diagnostic fracture injection test (DFIT) transients. Ideally, a plot of pressure versus G and G*dP/dG versus G should form a straight line. However, the G*dP/dG curve is very often curving. A typical DFIT transient is shown below.