Wells G and H are to the right of the river line and the Riley well is on the left. It should be noted the yellow and white curved lines on the EXCEL worksheet represent the Aberjona River. In this exercise, we will explore different well pumping rates and how they would affect groundwater flow in the aquifer underlying Aberjona River Valley. The Thiem equation is embedded into the cells of the worksheet and automatically calculates drawdown at specified distances based on cell dimensions. The solution to the Thiem equation assumes the the drawdown (s 2) at the distance (r 2) is zero. The model assumes the aquifer is isotropic, homogeneous, flat lying, infinite, flow is steady-state, wells discharge at the uniform rate, and the wells have no borehole storage. The worksheet is based on the dimensions and locations of wells G and H. This assignment utilizes the Thiem equation (see image below) in an EXCEL worksheet to create a two-dimensional groundwater flow model that computes drawdown relative to steady-state pumping from wells. This means that the pressure is uniform long the wellbore face, and the well is said to have infinite conductivity.Learning Module: Groundwater Flow and Wells G & H Student Assignment Overview Kuchuk extended the previous works (1, 11, 14) on pressure transient behaviour of horizontal wells to include the effects of a gas cap nd/or aquifer (15).Ī convenient model to represent the pressure behaviour in a horizontal drainhole is one that assumes no pressure drop in its interior during fluid flow. Daviau also analysed the pressure behaviour of horizontal wells, considering both infiniteconductivity nd uniform-flux inner boundary conditions (14). Ozkan compared the performances of horizontal wells and fullypenetrating vertical fractures (11–13). Thambynayagam used finite Fourier transforms to solve the anisotropic problem for the line-source case (1) they presented a solution for an infinite-conductivity horizontal well located in a semi-infinite, homogeneous and anisotropic reservoir of uniform thickness and width. Ramey to solve the 3D isotropic diffusivity equation (7, 9, 10). Most work dealing with the horizontal well pressure transient problem uses the instantaneous Green's function technique developed by A.C. Solutions to the pressure-transient response of a horizontal drainhole based on the use of source and Green's functions and In general, the techniques explaining the pressure-transient response in horizontal wells can be grouped into two categories: Analytical solutions for the pressure behaviour of uniform flux, as well as infinite-conductivity horizontal wells have been discussed in the literature (1–5). Interpretation of well tests from horizontal wells is much more difficult than interpretation of those from vertical wells because of a considerable wellbore storage effect, the three dimensional nature of the flow geometry and lack of radial symmetry, and strong correlations between certain parameters. An extensive literature survey on horizontal wells can be found. During the last decade, analytic solutions have been presented for the pressure behaviour of horizontal wells.ĭetermination of transient pressure behaviour for horizontal wells has aroused considerable interest over the past ten years. The use of transient well testing for determining reservoir parameters and productivity of horizontal wells has become common because of the upsurge in horizontal drilling. For both vertical and horizontal wells, steady-state and unsteady-state pressure-transient tests are useful tools for evaluating in situ reservoir and wellbore parameters that describe the production characteristics of a well.
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