A Case Study of Two-Phase Flow at the Roosevelt Hot Springs, Utah KGRA

Abstract

A well in the Roosevelt Hot Springs, Utah KGRA was flowed in 1978 and 1979 to obtain pressure and temperature profiles in the two phase (steam/water) zone. Both parameters were measured simultaneously and in real time, as a function of depth. Under flowing conditions, the maximum temperature recorded was 503°F (262°C) and maximum pressure, 954 psia (6.58 MPa). Flow rates as high as 580,000 lb/hr (73.3 kg/sec) total flow were measured using a modified James method. Comparison of test results with output of a two phase flow computer model was performed. Model results matched test data quite well at flow relates below 300,000 lb/hr (38 kg/sec); above that level, increasing deviation from test data was noted with increasing flowrate. The computer model was used to investigate the effects of casing diameter and Productivity Index on the flowrate that could be sustained well with 13 3/8 inch diameter casing in predicted to have a 24% greater flowrate than can be sustained in current 9 5/8 inch diameter well. The impacts of both diameter and PI are significant, and results show that well design can be optimized to maximize production when reservoir parameters are known.