Systematic Oil Flow Modeling in the Quasi-3D Approximation Yields Additional Terms that Allows for Variable Cross-Section Area Tubing

TL;DR

This paper develops a systematic quasi-3D oil flow model that includes additional terms for variable cross-section tubing, enabling analytic solutions and better understanding of flow phenomena.

Contribution

It introduces a unified modeling scheme for quasi-3D oil flow that accounts for tubing area variations, including analytic solutions and validation tools.

Findings

Derived equations for variable cross-section flow

Generated models from steady-state and transient cases

Provided insights into flow behavior with deposits or roughness

Abstract

A systematic model development for oil flow in quasi-3D (1D + 2D) is presented. Our approach provides a unified modeling scheme. Besides, additional terms are obtained, which allows for tubing area variation along the flow direction. The area variation can be modeled as analytic function or random fluctuation, as it could be the result of deposits or tubing internal surface roughness. The proposed approach can be used to obtain analytic solutions which provide physical insight into the phenomena under scrutiny, including the validation of software tools, sensor development and sensor placement. One starts from conservation laws as given by kinetic theory and applies the transverse averaging technique (TAT) to extract the one-dimensional approximation in formal grounds. To demonstrate its application, the steady-state Ramey's model, the Hasan's transient model and a simple two-phase model are generated from the obtained equations.