Back in 1950s, due to the lack of computational power, many simplifying assumptions had to be applied to model fluid flow in the well bore. Empirical correlations were developed to model complex fluid flow behavior for various types of fluids and well geometries. Since then, most of the research in the oil and gas industry focused on expanding on the earlier developed empirical correlations, without realizing that now we have enough computing power to solve the fundamental Mechanical Energy Balance Equation numerically.

At ODSI, our engineers took the approach of starting with the fundamental physics of fluid flow, combined with modern-day computing power. We model the fluid flow path and thermal profile of the well bore, use Equation of State-based PVT and perform parametric phase-thermal wellbore modeling to calculate the rates given two pressures in the well (WHP and DHGP), or to calculate the pressure profile if given one pressure and the rates.

Fluid PVT calibration is data-driven and can be performed with shut-in data from a well in real-time. This also allows us to calculate the Water Cuts and GORs for oil wells and to calculate the yields for gas and gas/condensate wells.

The purpose of this process is to provide valid bottomhole pressures (BHP) and multiphase rates, as well as to recognize when there is a wellbore lift issue. That allows engineers to focus on what is going on in the completion and in the reservoir.

For reservoir flow, we incorporate ALL of the important terms in the diffusivity equation, not just the first order terms that you’ll find in the textbooks (again, in the 1930’s, Hurst didn’t have computers, so he had to make a bunch of assumptions, including dropping out the higher-order terms). ODSI’s inclusion of higher-order terms like inertia and momentum and the inclusion of a 2nd Law of Thermodynamics constraint on the Energy Equation leads to a much better understanding of what is happening in the reservoir AND into how much oil and gas the well should produce.


Our job is to provide you with the most reliable information available, explain what it means, and present it in a way that helps you as an operator to make the best decisions.


We’re looking forward to helping you remove the guesswork and uncertainty around your wells so that you can make better, more profitable decisions.

Before you spend a lot of money figuring out a problem, call us and send us your data. You may already have the answer!