Wikia

Mining Well
Type	BuildCraft Machines
Stackable	Yes (64)
Data Value	dec:174
Mod Included	BuildCraft

The Mining Well will dig a hole straight down. It requires MJ, produced by Engines, to function. The Mining Well will stop drilling down once it hits lava or bedrock. Destroying the Mining Well without a pickaxe will result in the Mining Well being broken, with you unable to pick it up and place it again. The Mining Well leaves Mining Pipes down the hole it drills, which can be punched away and reused (or recycled). Blocks that the Mining Well digs out pop out of the Mining Well, unless there is a pipe attached. It essentially is a 1x1 Quarry.

You should also know that when powering more then 10 at one time you will need massive power. You would need at least 5 Energy Links hooked up to 5 High Voltage Solar Arrays each to make them go fast, and using one quarry would be more efficient and cheaper.

Caution: The piping left behind by the Mining Well will not fill up the entire block beneath it. Use caution when breaking your Mining Well as the block or even you may fall down the hole you have created.