These dewatering wells are designed to keep the refinery spillage out of the local aquifer.
While constant effort is made to keep spills and leaks down to a minimum, with all the tanks, piping and constant pumping and workings taking place at a refinery, spillage and leaks are part of the environment.
This refinery is on the outskirts of a large city.
Water for the city is predominantly drawn from the aquifer and no traces of petroleum or any other contaminants can be found in the water. Water quality is constantly monitored and extremely heavy fines and possible shutdown exist if standards are not kept.
The refinery has about 60 wells interspersed around the grounds and on the fringes. The wells on the circumference form a type of barrier to prevent any contamination reaching the aquifer. Groundwater is pumped to separator tanks where all contaminants are removed.
Alarms signal when a pump goes down and this is immediately reported to the sub-surface division. A crew is dispatched immediately to replace the pump and motor.
Removing rigid steel column
The steel column pipe is removed. Note the power cable in the foreground. This is a safety hazard but is part of removing rigid pipe.
Pump is ready to be lowered on Boreline
The pump has been connected to the Boreline and the power cable is attached along the length of the hose. The Boreline is rolled onto the hydraulic spooler and this is backed-up to the well. We are ready to install.
Installing pump and Boreline
The Boreline and power cable simply roll off the spooler and into the well. An added advantage when removing the pump is that the power cable does not have to be disconnected. It remains fixed to the Boreline; safe and secure.
Apart from the longer down-time experienced to remove rigid column pipe, an added problem is that these are covered with oil, which makes handling difficult and dangerous.