Calculating the flow rate of a horizontal open hole well

Based on literature survey on formulas for calculating flow rates, the authors conclude that the problem of calculating the flow rates of horizontal wells currently remains relevant. However, the emphasis is on reproducing the geometry of streamlines in gas flow as accurately as possible and insufficient attention is paid to the influence of flow friction forces when moving along the horizontal wellbore. In order to fill the gap on influence of flow friction forces when moving along horizontal wellbore, the article presents a semi-analytical model for calculating the flow rate of horizontal open hole well. The main attention is paid to depression drop due to flow friction along the horizontal wellbore, which significantly affects well productivity. Test calculations have been demonstrated the optimal horizontal section length is about 350 meters. The developed model allows us to give recommendations on selection of optimal length and diameter of horizontal wells for fields with known filtration and reservoir properties. The article also analyzes existing methods of flow rate calculation for horizontal wells and shows that traditional formulas lead to significant errors. Calculations and graphs demonstrate depression drop because of gas flow friction. The authors emphasize the relevance of accurate flow rate calculation for horizontal wells with designs other than an open hole and propose improved methods considering friction forces of gas flow. The developed model can be used for various geological conditions, providing accurate well productivity prediction. This research provides practical solutions for optimizing horizontal well parameters and minimizing calculation errors. Keywords: horizontal well; flow rate; permeability; dynamic fluid viscosity; reservoir pressure.