The lecture covers the process of drilling wells, focusing on the types of soil and rock encountered, and the methods used to drill and secure the well.
Geological Layers
Bedrock: The ultimate goal is to reach the bedrock as it's where water is found.
Overburden: Layers of clay, sand, gravel, boulders, and water sitting atop bedrock.
Thickness varies by location due to geological processes.
Drilling Process
Drilling Types:
Rotary Drilling Machine: Most common; diesel-powered, hydraulic, functions like a giant hammer drill.
Cable Tool Drilling: Less common; involves repeatedly dropping a drill bit to fracture rock.
Rotary Drilling Machine
Setup:
Machine arrives on a truck, supported by another truck carrying water.
Machine is leveled using feet to ensure a straight drill.
Drill Bit and Pipe:
Uses a tri-wheeled grinding tool.
The drill bit has holes for water and compressed air.
Drills 20-foot pipes sequentially until reaching bedrock.
Casing Installation
Purpose: Prevents overburden from collapsing into the well.
Method:
Uses 20-foot steel pipes with threaded ends.
Pipes are spun and welded for secure connection.
A drive shoe is used to drill casing into bedrock.
Sealing:
Gap between casing and borehole is filled with grout (bentonite clay).
Helps prevent contamination from surface water.
Encountering Water
Indicators: Water erupts violently from the borehole upon striking a water vein.
Flow Rate: Example noted a flow rate of 10 gallons per minute.
Pump Installation
Process:
A pump is lowered into the well using PVC pipes.
Pipes connected by threading, lowered using a crane.
Placement:
Pump placed 126 feet below water level to ensure ample water supply.
Allows for up to 130 gallons of water above the pump for immediate use.
Operation:
Pump rate matches the inflow rate (~10 gallons per minute).
Ensures constant water availability unless underground supply ceases.
Final Steps
Capping and Connection:
Well capped after pump installation.
Plan to install a pitless adapter for house connection.
Usage: Currently filling water tanks; future connection to house planned.
Conclusion
Summary of the well drilling process and installation.
Encouragement for feedback and sharing of personal well experiences.