Zero discharge mud system becomes more and more necessary for rig site. As the chemicals, heavy oil, and other kind of waste oil inside the drilling waste is hazardous to the environment. If the drilling waste has been discharged to the environment, the pollution cannot be recovered in short time or even for a very long time. Like in China and many countries, the governments have strict rules to control the drilling waste. Any oily waste or drilling waste cannot be on the ground. Unlike previous years, waste pit or mud pit is prohibited. GN Solids Control is a specialist for mud solids control and drilling waste management systems. GN specially designed zero discharge mud system is the ideal solution of drilling rig companies.
Recently, GN Solids Control will dispatch a complete set Zero discharge mud system for a rig fabrication company. Unlike normal drilling mud solids control system, the Zero discharge mud system is composed of a waste management system to recovery the drilling cuttings from the solids control shale shaker, desander and desilter. As the end user country accept Oil on cuttings (OOC) less than 5% for discharge. It is relative easy to reach.

Firstly, a set of vertical cuttings dryer is equipped for the 1500hp oil rigs. Why choose VG dryer rather than High G dryer? The reason is that, HG dryer is mainly used to treat the water based mud. It is not good at oil base mud. During drilling, in the first stage, they will use water base mud. When drill to a deep depth, they should change to oil base mud. GN patent design vertical cuttings dryer can be used for oil based mud, as well as water based mud. The rig site people do not need to change equipment when they change water base mud to oil base mud.

The cuttings after VG dryer is with OOC less than 5%. And it is dry enough for movement or discharge. The liquids recovered from VG dryer should be weighted for drilling. It should be treated by decanter centrifuge.

And then there is a high speed decanter centrifuge after the VG dryer to reduce the mud weight recovered from VG dryer. After remove some of the fine solids, the liquid mud can be back to rig mud system for drilling activities.