In 2006 Wallis Drilling made a strategic decision to enter the CSG (coal seam gas) market and although things were fairly similar to the mineral exploration market they had traditionally been involved in there were some new challenges.
The rotary drilling component they were familiar with now included mud cleaning and pumping equipment, areas which Wallis had never explored before.
After some discussion, research and an impending start date it was decided they would package a pump along with mixing gear internally. As Wallis had a long association with Dynapumps and the FMC product it was decided that these pumps would be the best solution for this project.
A FMC Q1832 unit was selected for the application; this unit is capable of producing 400 GPM at 1000 PSI continuous duty. The pump is powered by a Cummins M11 and driven hydraulically. The hydraulic drive is controlled remotely from the rig control panel and is infinitely variable across its speed range. The pump unit along with two 10,000 litre mud tanks mixing platforms and hoppers were fitted to a 45ft tri-axle drop deck trailer and has operated in the CSG for a number of years now. Along the way the unit has received a number of improvements to increase pump service life including some basic fluid cleaning equipment as well as improved inlet screening and boost conditions.
Wallis had to add another unit to the fleet in 2010, it was decided that an FMC pump again would be the most suitable solution for the package. With this unit, they wanted to increase the available working pressure of the pump primarily in the event it was used for well control duty. A FMC M2836 was selected; this unit is capable of producing 386 GPM at 1570 PSI continuous duty. The drive has been designed to run the pump to its intermittent rating and at this speed will produce 433 GPM at the same 1570 PSI. Again it was decided that we would drive the main mud pump hydraulically along with the shaker tables, boost, transfer/mixing and solids separation pumps. This hydraulic group is driven by a Cummins KTTA 19. The engine and hydraulic package has been fitted inside a sound attenuating enclosure. In the interest of circumventing zoning issues for a gaseous environment there are no electrical components fitted and the engine uses air start and a pneumatic shut-down system as well as being fitted with intake choke valve and spark arrestors on the exhaust. The pump unit and drive have been mounted on a 45ft triaxle trailer along with a single 25000 litre mud tank. All recycled fluid is passed through a two stage cleaning system incorporated in the package. The mud tank is fitted with two mixing platforms and hoppers at either end along with hydraulically driven agitators in the tank. The unit has also been fitted with an additional small hydraulic power pack driven by a VM SUN engine suitable for running the pump/mixing hopper assembly, tank agitators and one cleaning circuit when rig is coring so large drive engine doesn’t have to operated for these minor functions.
Wallis Drilling would like to acknowledge the technical input and support of our suppliers on this project; Dynapumps for the main FMC pump, Status flow pulsation dampers, Southern Cross boost pump and the Victor self prime pumps used for solids separation. Rexroth Bosch Group for hydraulic components, Innovative Fluid systems for drill fluid cleaning components along with Allied Heat Transfer, Cummins South Pacific, MTU Detroit Diesel Australia and Ashley Benoit.