The pressure potential curve surrounding a source (i.e., injection well) or sink (i.e., production well) does not have a constant radius, as is assumed in Sec 2.1.2. Thus, to gain a more precise solution for an ID, we integrate the distance of the potential curve surrounding the sink to obtain the cross-sectional area, given in Equation , where 𝑟 1 is the radius to the equipotential line from the sink and 𝜃 is the inclination.