Production Log Analysis Methodology

Production Log rate calculation is treated as a minimization problem and solved using nonlinear regression, with interpretation of RECON’s HDD ™ High Definition measurements; spinner apparent velocity, density, pressure gradient, capacitance, holdup, and temperature.

Local vs. Global Regression
The Rate calculation scheme used in the Analysis Package involves successively solving the cumulative rates at selected depths inside the wellbore. The contributions of the inflow zones, located in between the calculation zones, are then obtained from successive differences. Each local regression is run regardless of the solution above or below. The overall solution may result in contributions from the same interval showing different signs which, physically, is not possible. Therefore, global regression provides a method for solving these cases. For every producing interval, the sign of the contribution can be imposed. Global regression can be coupled with a genetic algorithm to avoid local traps.

Interpretation Models
RECON’s Log Analysis package offers a full range of flow models from single to three-phase flow. Specific models are provided to handle flow re-circulation as well as flow through standing water columns. Three and two-phase liquid-liquid stratified models for horizontal and highly deviated wells are available. It is also possible to connect user models through an external DLL interface.