[[:file:applying-gravity-in-petroleum-exploration_fig15-11.png|Figure 2]] shows how the depth of investigation is tunable by means of varying the separation between two gravity measurements, Δ''z''. The rule of thumb is that 90% of the gravity effect can be imaged at a distance away from the borehole within five times Δ''z''. | [[:file:applying-gravity-in-petroleum-exploration_fig15-11.png|Figure 2]] shows how the depth of investigation is tunable by means of varying the separation between two gravity measurements, Δ''z''. The rule of thumb is that 90% of the gravity effect can be imaged at a distance away from the borehole within five times Δ''z''. |