Effect of Completion Geometry and Phasing on Single-Phase Liquid Flow Behavior in Horizontal Wells

Abstract

Abstract Horizontal wells can have very complex flow geometries, in part due to interaction between the main flow stream and the influxes along the wellbore, and also due to completion type. An experimental facility was used to investigate the effects of completion geometries and the density and phasing of injection openings in horizontal wells. Three test sections with perforation densities of 5, 10 and 20 shots per foot and phasings of 360, 180 and 90 were. Four test sections were used for slotted liners, including one single slot case and three multiple slot cases. The numbers of slots for multiple slot cases were 18, 18 and 36 on 4-ft. long sections with slot phasings of 360, 180 and 90, respectively. A total of 1,257 tests were conducted for no fluid injection, no main flow at the test section inlet, and with fluid injection for Reynolds numbers ranging from 4,000 to 60,000 and for influx to main flow rate ratios ranging from 1/5 to 1/2000. Experimental results show that completion geometry, phasing and density in addition to Reynolds number and influx to main flow rate ratio have dramatic effects on the pressure behavior and therefore the production behavior of horizontal wells. A general friction factor expression for horizontal wells with multiple injection openings was developed based on the conservation of mass and momentum. A commercial Computational Fluid Dynamics (CFD) computer program was used to determine the length of the flow developing region in a horizontal well after the flow is disturbed due to radial influx. Applying experimental data and the result of CED simulation to the general friction factor expression resulted in new simple correlations for horizontal well friction factors. Very good agreement was found between the friction factor correlations and experimental data. A field example is presented to show the importance of using a proper friction factor correlation to calculate the pressure drop in a horizontal well. P. 93