How to Achieve Zero Disposal of Drilling Waste?

Apr 04, 2012

The first dozen years of 21st century saw rapid development in China and the whole world. Mechanical industry’s leading development has been driving up the demand for oil that led to thousands of oil projects, whose pollution also created tons of trouble to Earth’s environment. Here provoked a problem that needs a careful think of all oil explorers when environmental protection is being ever touchy nowadays,“ What should be done to make oil drilling more environment-friendly?”

First off, we need to ask ourselves “how should we achieve zero pollution in oil drilling?”

At the beginning of last century, drilling fluids concocted by chemical compounds were largely applied while drilling boreholes for improvement of its safety and efficiency. Drilling fluids have been especially useful in carrying out drill cuttings, providing hydrostatic pressure to prevent formation fluids from entering into the well bore, cleaning the bottom of wells, preventing oil and gas from flowing up the wells, keeping the drill bit cool and clean during drilling, etc, which has made it the “blood” of drilling equipment. However, just like every coin has two sides, it will turn into poisonous “blood” when it is discharged onto soil with cuttings since it may contain soluble inorganic salt, heavy metal, organic hydrocarbon ( oil substances ), etc, which could easily be made harmful via rain immersion and river brush to the surrounding soil, water source, farmland and air.

It is expected that our tentative efforts would make drilling waste management perfect, but the facts did not turn out so. Pollution resulted from oil drilling is still swallowing our healthy environment bit by bit and the problem is still vexing our nerves. Nevertheless, we cannot do without it because the drilling fluids have already been the “blood” in the industrial era.

Xi’ an KOSUN Machinery Co., Ltd. who has been specialized in oil drilling machines began seeking for solutions on site in order to truly green oil drilling. Waste disposal was the biggest problem for oil drilling contamination. We need to minimize it and even better, zero it, then we can achieve greening of oil drilling.

Via 20-year grueling efforts from 1990s to early 21st century, KOSUN has developed oil drilling solids control system and waste management equipment and has set up an integrated waste management solution system by combination of domestic and foreign treatment experience learnt on site.

This solution would deal with disposal at the source by means of solids control equipment, dewatering purification equipment and waste management equipment.

The first part---solids control equipment, comprising shale shaker, vacuum degasser, desander, desilter, decanter centrifuge, is directly connected to mud pumps. The drilling mud drawn out from well will go through the four phases of solids control system. Afterwards, it will be used again and the disposal is minimized at the same time.

The next part after solids control is dewatering and water treatment, via which water may be effectively recycled. If they are applied in water-scarce area, large amount of water would be saved and waste disposal reduced.

Then, screw pump or screw conveyor may transport dewatered waste to Hi-G Dryer and Vertical Centrifuge, waiting to have solids and liquid separated again. Hi-G Dryer’s high spinning speed and effective treatment will produce very dry dregs, recover partial drilling fluids and recycle resources.

In the end, the dregs will be further treated by means of solidification, cutting injection, biodegradation, thermal desorption according to the actual situation on the site of drilling and the composition of dregs.

Drilling waste disposal will be reduced to almost zero after going through the system, effectively satisfying the demands for zero disposal and the state environmental protection regulations, solving the vexing problems in oil drilling, and truly fulfilling the wish of “green drilling” in oil industry.