Research on the influence mechanism of fluid control valve on the production of segmented horizontal wells and the balanced gas production control model: A case analysis of Sichuan basin natural gas

The existing research on the multiple fluid control valves to control the balanced exploitation of natural gas in horizontal wells lacks theoretical model support. On this basis, this paper established a flow rate and pressure model of the segmented horizontal well based on the fluid control valve. The model considers the throttling performance, installation position and opening adjustment step size of the fluid control valve for the first time. Next, systematically analyzed the mechanism of mutual influence of the opening and the position on the flow rate and pressure based on multiple fluid control valves. In addition, a novel method of using the dichotomy model to adjust the production of different production segments was proposed to analyze the horizontal wells of 15 production segments in Sichuan. It was found that when the opening adjustment step size is less than 5%, the natural gas production shows irregular changes, which makes it hard to effectively control the production of each segment. When the step size is 5%, the maximum production variation is 2.7%, which will have a more significant and meaningful effect on the exploitation of natural gas. Through seven iterations, the maximum production errors of high and low production segments are 1.3 % and 1.1 % respectively, both less than 2.7%. The research results verified the correctness of the theoretical model of segmented horizontal wells based on multiple fluid control valves. This research provided a theoretical basis for the opening control of multiple fluid control valves based on different production segments of horizontal wells.