A Decline Curve Pitfall Using Least-Squares Solution
Leo A. Schrider, Richard E. Cerullo · Journal of Petroleum Technology · 1970
In the solution of the exponential and hyperbolic decline curves by least squares, petroleum engineers normally attempt to pick for these equations constants that "best" agree with the production decline. Unfortunately, these solutions for the constants taken from the least-squares line are not necessarily the "best" fit to the data. As an example of this type of solution, let us consider an exponential decline-curve equation familiar to most petroleum engineers: Equation (1) This equation is frequently referred to as the semilog decline-curve equation. The semilog title arises from the fact that production data satisfying this type of exponential equation plot as a straight line on semilog paper.