This paper proposes the concept of variable-permeability effect and sets up the one-dimensional and two-dimensional non-Darcy well testing models. The finite difference algorithm is employed to solve the differential equations of the variable-permeability model, and the non-convergence of the numerical solutions is solved by using the geometric mean of permeability. The type curves of pressure and pressure derivative with variable-permeability effect are obtained, and sensitivity analysis is conducted. The results show that the type curves upturn in the middle and late sections, and the curves turn more upward with the severer of the variable-permeability effect. The severer the non-Darcy effect is, the less obviously the curve upturns caused by boundary effect. Furthermore, the boundary effect is increased by increasing the number of impermeable boundaries or decreasing the distance between the well and boundary.
EARTH SCIENCES RESEARCH JOURNAL
A study was conducted to investigate the effects of the flow velocity and the paving material on the nitrogen conversion rates in shallow open channels. Equal amounts of hollow holed and plain balls, all with a 3.5-cm diameter, was fastened to the channel bottom. Then the nitrogen conversion rates were taken at various velocities and compared. The inner and outer surfaces of the holed ball channel were about 1.5 times than of the plain ball channel, but the attached biofilm mass was found to be about 3.55 times greater. The optimal nitrogen conversion rates were found to be higher in the holed ball channel. A suitable velocity was determined which would enhance the optimal nitrogen conversion rates. The choice of velocity and the biofilm carrier to enhance or predict the nitrogen transformations in shallow channels, should be considered in model development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.