Abstract: Through theoretical formula derivation and single factor influence calculation,the influencing factors of pressure drop in the horizontal well section caused by frictional resistance are identified. Based on the actual reservoir characteristic parameters,an analysis chart is established for the variation of pressure drop in horizontal well sections with different liquid production scales and water cut stages in Bohai Q Oilfield. The ratio of the pressure drop in the horizontal section to the production pressure difference of this well is defined as the C value. Combined with the the production pressure difference,the potential of single well measures in Bohai Q Oilfield is quantitatively predicted. It is proposed that 13 wells implement large pumping for liquid extraction. After the operation,the oil production increases by 403 t/d,achieving good application results.

Key words: pressure drop in horizontal well section, production pressure difference, quantitative prediction, influencing factors