Experiment of complex flow in full size horizontal wells with perforated completion

A full size perforated casing of 139.7 mm in external diameter was adopted to simulate the horizontal wellbore. The influences of perforation parameters and injection rate on the pressure drop in horizontal wells were investigated by experiments. The results show that: (1) With the increase of perforation density, perforation diameter and perforation phase, both the frictional pressure drop and the total pressure drop increase and the mixture pressure drop decreases. (2) When the mainstream Reynolds number at the perforated casing exit remains constant, with the increase of injection rate, the total pressure drop and mixing pressure drop increase. When the injection rate is less than the critical injection rate (0.05%–0.10% under the study conditions), the mixing pressure drop is less than 0. When the injection rate is greater than the critical injection rate, the mixing pressure drop is greater than 0. The acceleration pressure drop can be neglected when the injection rate is less than 0.10%, otherwise the acceleration pressure drop rises significantly with the increase of injection rate. (3) With the increase of injection rate, the proportion of frictional pressure drop to total pressure drop decreases while that of acceleration pressure drop to total pressure drop increases. When the injection rate is less than 1.00%, the proportion of mixing pressure drop to total pressure drop tends to rise with the increase of injection rate. When the injection rate is greater than 1.00%, the proportion of mixing pressure drop to total pressure drop almost remains unchanged.