A generalized equation for calculating the productivity of vertical and horizontal wells in homogeneous and stratified reservoirs

Abstract EN

An equation for calculating the productivity of a horizontal well producing under pseudo steady-state flow is presented.

It is easy to use and is identical in form to that used for a vertical well.

With the proper changes in variables, the equation can be generalized to cover vertical wells.

The drainage volume is assumed to be box shaped, and permeability anisotropy in the x, y and z-directions is accounted for.

This feature is novel to the Industry.

The productivity of a horizontal well in a stratified reservoir with cross flow is also given in an equation form, similar in structure to that of a one layer reservoir.

These equations were derived from very complex general solutions.

Example calculations illustrating the use of the equations are given.