A Brief History of Drilling Fluids Solids Control

May 16, 2012

Anyone having a broad familiarity with oil & gas drilling knows that drilling fluids is quite indispensable in oil drilling. It is mainly used to help the drilling of boreholes. There are three main categories of drilling fluids: water-based drilling fluids, oil-based drilling fluids and gaseous drilling fluids.

Drilling fluids is truly functional in drilling industry since it is able to remove cuttings from wells, suspend and release cuttings, control formation pressures, seal permeable formations, maintain wellbore stability, cool, lubricate and support the bit and drilling assembly, minimize formation damage, etc.

However, due to the precious materials used in drilling fluids, once it is deserted, it is fairly hard and expensive to produce and concoct another. What is more, drilling fluids is not automatically recyclable since the solid phase, cuttings and gases will penetrate and change its performance from many aspects, for example, the active clay included in cuttings will exert greater negative influence on its viscosity, thus causing difficulties in drilling and forming filter cake.

Many oilfields and companies injected water or other chemical fluids to dilute drilling fluids for maintaining certain density and visocity. Later, mud bits were discovered as more effective and less costly. They were required for holding an excess volume of drilling mud at the surface, which allows time for settling of the finer rock cuttings and for the release of entrained gas bubbles not mechanically separated. With the development of scientific technology and raise of mud treatment standards worldwide, nowadays mud circulating system also includes various solids control equipment such as shale shaker, hydraulic cones, centrifuges, degassers and so on.

This addition has largely improved mud treating effects, reduced the considerable cost on drilling fluids and borehole maintenance, and kept drilling workers and environment from fatal damages.

Shale shaker is the first grade equipment for solids control system. It is quite useful for separation of solid phase above 75 μm in diameter. Then, it sends the mud into the next grade---desander for more delicate separation of solid phase between 45-74 μm in diameter. Treated mud will flow into desilter, the third grade equipment for further treatment where the 15-44 μm cuttings will be taken away. In the fourth grade, low-speed and high-speed centrifuge respectively remove tiny particles like barites and infinitesmal substances that is 2-5 μm in diameter. If the drilling mud is entrained by gases, degasser can be installed between shale shaker and desander.

After drilling mud goes through all the processes, they can be very well recycled and re-applied in oil drilling.

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 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.