For offshore drillings, one of the biggest drilling waste is sewage which grows out of drilling fluids, rain, water used to wash bits and cooling water. Usually, the under-treated sewage weighs 30 times the well-bore volume. Therefore, sewage minimization is a very vital part in the whole waste treatment.

However, as the easiest waste resource to be reduced, water can be reduced in such ways as below:

One-way cooling system can save water and seal it inside the system while eliminating cooling water, braking water and sealing water to achieve water recycling. It is proved that it is not pricey to recycle the water and is able to save a large amount of liquids.

The reason that rain can be recycled is the correlation between drilling fluids and water. Rain is applicable in washing drilling equipment. The water used to wash drilling equipment can flow into water tank just like rain and should be recycled till it cannot function any more. It will be surprising to see how many times they can be reused.
 

The dirtiest water ( such as, deserted drilling fluids ) can be applied to wash the panel. Desander and filter can produce massive deserted drilling fluids( usually there is one portion of solid phase in 2 or 3 portions of fluid phase ). They can be used to wash drilling mud tank. And shale shaker and decanter centrifuge also need washing water. Water used to clean panel do not need purifying since it is not necessary to wash away solid phase and liquid phase with clean water. It will be very difficult to separate them during treatment procedure.

It is necessary to produce sewage. It is quite expensive to treat sewage, so vacuum device is preferable to washing water here. A gun-shaped controller with tube is a good idea. The tube falls and automatically closes the connection to disconnect the controller. Drilling operators prefer high-pressure, small-volume washer due to the less labor intensity, better washing effects and reduced sewage volume. Generally speaking, both the vacuum device and washer are put into use when treatment is not costly. However, the gun-shaped controller will offset the cost. Different approaches can be conducted to separate and treat waste, for instance, water-based waste and oil-based waste can not blend until being managed together. During the operation, fluid from drilling mud pits should be reinjected so as to flow into spare drilling mud pits.

Key words:

KOSUN: Established in 1992 and headquartered in Xi’an China, Xi’an KOSUN Machinery Co., Ltd. ( KOSUN ) is among the first group of manufacturers of oil drilling high-frequence shale shakers, is a specialized centrifuge producer, the pioneer in the field of solids control in China, as well as an expert in drilling waste treatment. Its business scope mainly covers China mainland, Commonwealth of Independent States, North Africa and U.S.A.. Solids control equipment: Its performance and quality play an important role in solids control technology. Drilling solids control system mainly contains such three parts as drilling fluids circulating tank, drilling fluids purification equipment and electric control equipment, among which the drilling fluids purification equipment includes oilfield shale shaker, desander, desilter, degasser, centrifuge, centrifugal pump, agitator, mixer, etc. Cuttings recovery and waste fluids treatment equipment can also be coupled for the environmental sensitive areas.