Based on the Dikken analytical calculation method of wellbore pressure loss under single-phase fluid and turbulent flow conditions, the correlation model between horizontal well output and horizontal section length an...Based on the Dikken analytical calculation method of wellbore pressure loss under single-phase fluid and turbulent flow conditions, the correlation model between horizontal well output and horizontal section length and horizontal section distributed pressure difference is constructed. The influence degree of wellbore pressure loss on daily oil production of horizontal well, horizontal section pressure and production effect of horizontal well under different horizontal well lengths is analyzed, which provides certain reference for the design of horizontal well length and well layout.展开更多
Philip’s two-term infiltration equation has been widely used to infer soil saturated hydraulic conductivity(Ks),the accuracy of which is usually influenced by the size of infiltration rings and soil conditions.Previo...Philip’s two-term infiltration equation has been widely used to infer soil saturated hydraulic conductivity(Ks),the accuracy of which is usually influenced by the size of infiltration rings and soil conditions.Previous studies have primarily focused on exploring the ring-size dependence of Ks estimations under specific soil conditions(e.g.,soil isotropy and/or uniform initial water content).This study aimed to provide a comprehensive analysis by systematically considering eight heterogeneous and anisotropic soils with nonuniform initial water contents.Specifically,we examined the validity of Philip’s infiltration equation as well as the recently proposed two forms(i.e.,infiltration and time forms)of Parlange’s infiltration equation both theoretically and in practical applications of double-ring infiltration.Then the time form of Parlange’s equation was applied to infer Ks using double-ring infiltrometer measurements with different combinations of six inner ring diameters(10,20,40,80,120,and 200 cm)and three buffer index(defined as the ratio of the difference between inner and outer ring diameters to the outer ring diameter)values(0.20,0.33,and 0.50).For each infiltrometer set,20 stochastic Ks fields were randomly generated by adopting five standard deviation values(0.1,0.3,0.5,0.7,and 0.9).Furthermore,we investigated the effects of five horizontal correlation lengths(30,60,150,300,and 600 cm)on Ks estimations.The results demonstrated that Parlange’s equation,compared to Philip’s equation,was more universal in describing the cumulative infiltration relationship for the test soils.The combination of inner ring diameter and buffer index of 40 cm and 0.2,respectively,which satisfied most of the practical requirements for determining Ks in the Soil Water Infiltration Global(SWIG)database was optimal.When the horizontal correlation length exceeded a threshold(i.e.,150 cm in our study),the inner ring diameter was required to increase to 80 cm.Our findings contribute to accurate Ks estimations of different soils using double-ring infiltrometers.展开更多
文摘Based on the Dikken analytical calculation method of wellbore pressure loss under single-phase fluid and turbulent flow conditions, the correlation model between horizontal well output and horizontal section length and horizontal section distributed pressure difference is constructed. The influence degree of wellbore pressure loss on daily oil production of horizontal well, horizontal section pressure and production effect of horizontal well under different horizontal well lengths is analyzed, which provides certain reference for the design of horizontal well length and well layout.
基金supported by the National Natural Science Foundation of China(Nos.42107066 and 42007004)the Natural Science Foundation of Jiangsu Province,China(No.BK20201105)。
文摘Philip’s two-term infiltration equation has been widely used to infer soil saturated hydraulic conductivity(Ks),the accuracy of which is usually influenced by the size of infiltration rings and soil conditions.Previous studies have primarily focused on exploring the ring-size dependence of Ks estimations under specific soil conditions(e.g.,soil isotropy and/or uniform initial water content).This study aimed to provide a comprehensive analysis by systematically considering eight heterogeneous and anisotropic soils with nonuniform initial water contents.Specifically,we examined the validity of Philip’s infiltration equation as well as the recently proposed two forms(i.e.,infiltration and time forms)of Parlange’s infiltration equation both theoretically and in practical applications of double-ring infiltration.Then the time form of Parlange’s equation was applied to infer Ks using double-ring infiltrometer measurements with different combinations of six inner ring diameters(10,20,40,80,120,and 200 cm)and three buffer index(defined as the ratio of the difference between inner and outer ring diameters to the outer ring diameter)values(0.20,0.33,and 0.50).For each infiltrometer set,20 stochastic Ks fields were randomly generated by adopting five standard deviation values(0.1,0.3,0.5,0.7,and 0.9).Furthermore,we investigated the effects of five horizontal correlation lengths(30,60,150,300,and 600 cm)on Ks estimations.The results demonstrated that Parlange’s equation,compared to Philip’s equation,was more universal in describing the cumulative infiltration relationship for the test soils.The combination of inner ring diameter and buffer index of 40 cm and 0.2,respectively,which satisfied most of the practical requirements for determining Ks in the Soil Water Infiltration Global(SWIG)database was optimal.When the horizontal correlation length exceeded a threshold(i.e.,150 cm in our study),the inner ring diameter was required to increase to 80 cm.Our findings contribute to accurate Ks estimations of different soils using double-ring infiltrometers.
