Productivity Analysis Of An East Texas Gas Well

A Productivity Analysis is presented for an already completed East Texas well which produces gas at 1-3 MMscf/D from a 16 foot producing interval. The purpose of the analysis is to determine the potential additional production from re-perforating the producing interval or from perforating an additional interval that is not initially perforated. A Productivity Analysis requires a reliable value of the average permeability of each interval that is under consideration. For the subject well, there are no drill stems tests or core analyses to support permeability determinations. A set of open hole logs includes gamma ray, caliper, density-porosity, neutron-porosity, and deep resistivity. By use of computer analysis of the open hole logs, a permeability index is obtained for both the producing interval and the additional interval that may be perforated. For the producing interval, the average of the permeability index is far too small, considering the interval's height and its production rates, leading to the conclusion that the producing formation is probably naturally fractured.