Drawdown distribution in the vicinity of nonvertical wells

Subsurface water extraction systems are evolving to include nonvertical well designs. Traditional models for vertical and horizontal wells do not fully capture the behavior of inclined wells. The need for accurate drawdown predictions in these systems remains unmet. Existing equations fail to account for the full range of well inclinations. This gap motivates the development of new modeling approaches. Prior research has focused on either vertical or horizontal wells exclusively. No prior work had resolved the intermediate cases. This limits the applicability of current models to real-world scenarios.

This study aims to develop a universal drawdown equation (UDE) for inclined wells. The goal is to provide accurate predictions for aquifer systems with nonvertical wells. The UDE must work across a range of inclination angles from 0° to 90°. The approach should be computationally efficient and broadly applicable. The study also seeks to validate the UDE against existing models. Comparisons with vertical and horizontal well equations are essential. The UDE must be tested in real-world pumping data. This will ensure the model's practical relevance and accuracy.

The UDE is derived using the principle of superposition and standard well hydraulics. The method assumes fully penetrating observation wells for accurate drawdown measurements. The UDE is applied to three aquifer types: confined, unconfined, and semi-confined. Analytical solutions are compared with traditional vertical and horizontal well equations. A numerical model is used to validate the UDE for slant wells. The UDE is tested with real data from the Dana Point project in Southern California. The computational approach avoids complex numerical simulations. The method relies on established principles of well hydraulics.

The UDE successfully calculates drawdown for wells with inclination angles from 0° to 90°. The UDE aligns with analytical solutions for vertical and horizontal wells. Drawdown predictions match numerical models for slant wells. The UDE is computationally simple and requires minimal assumptions. Real-world data from Dana Point supports the UDE's accuracy. The UDE outperforms conventional equations for nonvertical wells. The model handles confined, unconfined, and leaky aquifers effectively. The UDE provides a unified framework for inclined well analysis.

The UDE offers a reliable method for predicting drawdown in inclined wells. The approach is computationally efficient and broadly applicable. The UDE matches analytical and numerical models for vertical and horizontal wells. Real-world validation confirms the UDE's practical utility. The UDE requires only standard assumptions from well hydraulics. The model avoids the need for complex numerical simulations. The UDE is suitable for confined, unconfined, and leaky aquifers. The study demonstrates the UDE's value for subsurface water extraction systems.