... is represented by gas lift performance curve (GLPC), which could be obtained implicitly from a two-parameter family ordinary nonlinear differential equation, which represents steady flow equation along the tubing, satisfying wellhead pressure and bottomhole pressure as boundary conditions. In a dual gas lift...

...A. Baumgart A mathematical model for the drilling process is derived and solved numerically as an initial value problem. The equations of motion are nonlinear differential equations for longitudinal, lateral, and rotational motion of the pipe as well as for the rate of flow and pressure of the mud...