how to calculate the volume of a well. introduction discuss which dimensions are needed. how to...
TRANSCRIPT
Introduction
• Discuss which dimensions are needed.
• How to obtaining the dimensions.
• Example
• Alternative method
Goals of this Presentation
• Establish the importance of properly calculating the volume of a well.
• Describe the dimensions that are needed for the calculation and how to obtain them.
• Create a clear understanding of the calculations through an example problem.
• Describe alternate methods to completing the calculations.
Why is this important?
• The volume of the well is used to determine the amount of plugging material needed.
• The volume is also used to determine the needed amount of disinfectant.
• Assuming the wrong volume of the well could lead to many future problems.
According to the video what dimensions are needed in order to accurately calculate the volume of
a well?• Well diameter
• Total depth
• Depth of the water
Obtaining Well Dimensions
• Diameter of the well – measured distance across the inner lip of the well
• Total well depth – measured distance from top to bottom of well.
• Water depth – measured distance of depth of water in the well. (Tie a weight to some string and drop it to the bottom of the well. Retrieve the string and measure the portion of the string that is wet.)
Hand Dug Well Example
• You have large hand dug well that is 3 feet in diameter and is 45 feet deep. The depth of water in the well is 10 feet.
Hand Dug Well Example
• The volume of the well is calculated by the formula.
V = ((Π * D2)/ 4)* d
Where :
Π= 3.1416
D=diameter of well (feet)
d= depth of well (feet)
Hand Dug Well Example
• The volume of the well is
V= ((3.416* 32)/4) *45
V= 318.53 ft3
1 yd3 = 27 ft3
V= 11.79 yd3
Example
• An abandoned well is 6 inches in diameter, 100 feet in depth, and the water level is 40 feet.
Well or Hole Diameter
Cement Bentonite Chips
Inches Linear Feet Linear Feet
2 50.3 31.3
3 28.8 13.9
4 16.2 1.9
5 10.4 5
6 7.2 3.5
7 5.3 2.6
8 4 2
9 3.2 1.5
10 2.6 1.3
12 1.8 0.86
14 1.3 0.63
16 1 0.48
18 0.8 0.38
20 0.6 0.31
24 0.4 0.21
36 0.2 0.097
40 0.16 0.078
44 0.13 0.065
48 0.11 0.054
Alternative Method
• Bags of cement needed (94 lb per sack)
100 feet / 7.2 feet = 13.8 sacks
• Bags of Bentonite needed (50 lb per sack)
100 feet / 3.5 feet = 28.5 sacks