OVERVIEW

Methodology

The drilling technique we use is a Rotary Mud System.

On the bigger wells that are drilled, a top start casing will be cable tooled into place by using a crane. This is to hold all loose upper ground materials. When this is installed that hole will be cleaned out. The main bore drilling follows and the hole is held open with drilling mud. As the cuttings are pumped to the surface and travel across a Shale Shaker screen, the material is recorded. This is referred to as the bore log. When a water bearing aquifer is discovered, a sample of the material is taken to determine the slot size of the water well screen. Casing pipe is installed down to the aquifer and the screen is lowered into the casing down to the aquifer and locked into place. Wanganui Well Drillers Ltd has developed a mechanical seal at the top of the water well screen. When tightened this means that the well is secure and water is free of contaminants such as silt and sand. The mechanical seal also allows for the easy removal of screens if maintenance is required.

Bore Logs and developing your Bore Quote

Wanganui Well Drillers has built up a comprehensive library of bore logs. These provide a geological profile of the strata that is drilled through when looking for a water bearing aquifer. It is with some confidence that the company can advise at what depth water might be found. Depending on the client’s water requirements, we could quote on a 4” bore for a shed supply, or 6” to 8” bore for a farm supply, to a 12” irrigation bore for crops or for a dairying operation. The quote is obligation free. “Lyle will meet with the client to discuss the quote and where the bore is to be drilled.”

Screens

Water occupies the space between sand and gravel in an aquifer. A screen is used to keep the sand and gravel out when pumping the water.

During the drill process a sample of the aquifer material is retrieved and analysed to determine the size of screen required, so that the sand and gravel does not enter the well and damage the pump.