1 / 11

WELL HYDRAULICS

WELL HYDRAULICS. Well Hydraulics. What is well hydraulics? To understand the processes affecting when wells are pumping water from an aquifer Why is it important?

wilmet
Download Presentation

WELL HYDRAULICS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WELL HYDRAULICS

  2. Well Hydraulics What is well hydraulics? To understand the processes affecting when wells are pumping water from an aquifer Why is it important? Ground water withdrawal from aquifers are important to meet the water demand. Therefore, we need to understand well hydraulics to design a pumping scheme. The easiest way to understand well hydraulics is to study a Single-well behavior in an aquifer under steady flow conditions.

  3. Transient Flow to a Single Well Confined aquifer Assumptions • Well is pumped at a uniform rate • Well is fully penetrating across the aquifer thickness • Aquifer is homogeneous and isotropic • Well/screen losses are ignored

  4. Transient flow in a confined aquifer with one pump Question What is the drawdown, s at distance r and time t for pumping rate Q? s=h0-h

  5. Theis Solution Solution to the transient confined aquifer flow equation is where Note: u is dimensionless

  6. Theis Solution Use the Well function [W(u)]table and find drawdown s as Theis solution can be used to estimate drawdown in an unconfined aquifer as long as the drawdown s is not large; i.e., compared to the initial thickness of the aquifer.

  7. Well function Table

  8. Example A well is pumping from a confined aquifer at a rate of 10,000 m3/day. The transmissivity and S of the aquifer are 1000.7 m2/day and 0.0001, respectively. Find the drawdown with time at two locations 100 and 200 m from the well.

  9. Example Procedure • Pick a series of times for each observation location. • Knowing the radius, r, time, t, T, S, and Q, find u for each time value. • Using the well function, find W(u) for each u • Use the solution to find s at that r and t.

  10. Predicted drawdown with time

More Related