Evaluation of Two-Phase Flow in Geothermal Well Pipes Utilizing the Orkiszewski Model

Abstract

The forecast models for evaluating energy losses in two phase flow are very useful tools in the design and operating aspects of pipe systems, and particularly in geothermal operations where pressure conditions, mass flow, as well as distances the fluid travels, are relatively long compared with other processing industries. In this paper a comparative analysis is presented between field measurements of a select group of vertical wells in the Cerro Prieto field and a completed program using the Orkiszewski method for the calculation of the drop in pressure and the flow pattern from the bottom of the hold to the wellhead. The program gives additional information of punctual pressure condition, temperature, quality, speed of liquids and steam, as well as static and frictional gradients in fixed increments of the path. In the implementation of this program, the effect of dissolved or suspended salts was not considered, nor was the effect of noncondensable gases on the physical chemical properties of the fluid. The wells discussed below were selected to cover a wide range of operational conditions. The results show a standard deviation of about 9 percent between the pressure measured at the bottom of the hole and that calculated, which for certain purposes of design and operation may be satisfactory.