Original Gas In Place (OGIP) From Gas Material Balance.

This Gas Material Balance application is designed to handle 10 data points,to use this application
first change the value of n to your number of data points,edit the table by double clicking
and changing the cells starting from the initial production.Add more values if your data is more
than 6 points and press enter and the chart will be replotted.

m1 and (P/Z)1 is the automatic fitted gradient and intercept of the data points.

If you're not satisfied with the automatic trend line(green line) and its results U can use the
Manual line fitter(red line) and its derivatives by taking the following steps.

(1)Change the value of m2 to something close to m1.
(2)Change the value of (P/Z)2 to some close to (P/Z)1.
(3)Delete (P/Z)1 and OGIP1 to remove the green line.
(3)Keep changing the value of m2 to rotate the red line.
(4)Keep changing the value of (P/Z)2 to move the red line upward or downward.
(5)After you've fitted the red line then m2,(P/Z)2 and OGIP2 becomes your new results

NB : P/Z for initial production(Gp0) is usually very reliable so U can retain and use it
by changing m2 to m1,(P/Z)2 to P/Z, OGIP2 becomes your new results