Paper: Single-Phase Flow in Horizontal Pipelines

Horizontal single-phase flow in a pipe network occurs frequently in oilfield operations. The field engineer may need to predict with reasonable accuracy the pressure loss in these lines. Nomographs from a handbook or appropriate equations from a fluid mechanics text can be employed for these calculations. The equations for Reynolds number and pressure loss in most textbooks will not have been derived in commonly employed field units, requiring numerous conversions which are excellent sources of error. To further complicate these calculations, Moody diagrams appear in the literature with two different sets of values for the friction factor. A calculated pressure loss would be in error by 400 per cent if the wrong friction factor were used. In this paper the equations for Reynolds number and pressure loss are defined in field units. Examples are included to illustrate the calculations. In addition, a listing of a computer program for calculation of the Darcy friction factor is given for the engineer who has access to a computer or terminal.