Estimating the Economic Limit of Gas Production

In this project, I employ 4th Order Runge-Kutta methods to estimate the gas production every thirty days in one example (given parameters to me in my PETE 301 class) of a gas producing field. The parameters of this specific project are given in the box at the top left. After given this specific data, this excel file can be employed to accurately estimate the life of the project. In the VBA Code, a z factor and viscosity macro is assigned to the worksheet to help calculate these production rates.

This estimate is meant to be more accurate than the traditional decline curve analysis methods used.

In the first tab, the 4th Order Runge-Kutta methods were used to iterate the estimated value of gas production at the specified time of the project. With these values, the trapezoidal method is employed to provide a comparison between the two. I am currently working on changes in the trapezoidal method's VBA code because, although the trapezoidal method should have more error than the 4th order numerical method I have applied, the error is much larger than I anticipated. This is the first version of my project in estimating the gas in place and I am currently adjusting and modifying this project for its second version.

For this specific project, the life is expected to last 3,465 days (9 and a half year long project) until the field reaches its economic limit of 469.3 Mscf/day.

Excel VBA File: https://www.mediafire.com/file/yav5wd0263143z4/Gas_Production_Analysis_Project_Bradley_Klawunder.xlsm/file