Experimental study on water level and absorption capacity in a radial well flow in a loess area

Abstract

In this paper, the theoretical basis for flow calculation in an injection well was discussed. It proposed that the flow rate of an injection well could be calculated referring to pumping theory and method. A mathematical model of the rising curve of water level around a radial well was established and the equation for calculating the rising curve was given. The calculation equations selected for the water absorption capacity of injection wells were explained and examples were verified and compared. The results indicated that, under the same injection conditions, the water level value calculated by the analysis method was slightly larger, but the error between the analysis method and the semi-theoretical and semi-empirical methods was small. In the processes of steady flow injection and unsteady flow injection, there was a small difference of water absorption capacity, and the former was slightly larger. The measured values of water absorption capacity were only about one-third of the calculated values based on pumping theory. Overall, the analytical solution method for predicting the rising curve of water level has priority in well injection. The semi-theoretical and semi-empirical equation for calculating water absorption capacity sifted first has priority in steady flow injection, the equation sifted second has priority in unsteady flow injection.

Comparison and study of several methods for solving the hydraulic jump values in pumping well

“…After preliminary debugging, the line nature of water level data fitting curve at N1, N2 and N3 was logarithmic, while the line nature of water level data fitting curve at N4 and N5 was slightly distant is close to parabolic, which is not included in this fitting debugging. This result is different from the previous studies [10]. The curve fitting process is shown in Figure 2.…”

“…In previous studies, the fitting method was adopted to screen out the water level curve, by taking advantage of the quick advantage of computing software. By extending to the well wall, the water level could be estimated, thus indirectly confirming the jump value, supplementing and modifying the analytical solution [10]. However, the available data for fitting the water level curve around the well is limited, the fitting curve equation is not representative enough, the position curve near the pumping well changes dramatically, and the extension direction is difficult to control.…”

“…In our earlier studies, we have reported a preliminary exploration on the estimation of hydraulic jump value [10]. In the existing research experience, a few methods were put forward to calculate the characteristics of the water jump.…”

In-situ pumping tests and numerical simulations of seepage wells in the Yellow River valley, China

“…Wang et al (2013) improved the model by taking the exchange yield between the radiant pipe and the aquifer as the coupling key, which realized the calculation of multiple seepage wells working simultaneously. Zhang et al (2018) proposed that the flow rate of injection wells could be calculated by the pumping theory of radiant wells and established a mathematical model of the rising curve of water level around a radial well. Maroney & Rehmann (2017) developed a mathematical method to calculate the stream depletion rate for a radial collector well in an unconfined aquifer near a fully penetrating river.…”