Solid control system overview and workflow

The generation of solid control system

During the drilling process, mud enters the formation through the drill pipe, and the drilling fluid is discharged together with the drilling waste after being used. Because mud is expensive and can damage the environment, the solid control system comes into being in this situation.

The solid control system of oil drilling is mainly to control and separate the solid substances in the drilling fluid, such as sediment and gravel, so that it can be recycled, also known as the mud purification system.

Solid control system overview

In the process of drilling, often encountered rock, gas or underground hot springs, in the process of rock drilling, the huge friction of the rock is very harmful to the drill, and in the drilling encountered gas or hot springs is easy to cause kick, blowout, in this case will be used mud.

Mud is usually water, oil, or a mixture of oil and water that contains a large amount of suspended matter, jelly. Mud can be divided into water-based mud, oil-based mud and mixed mud.

During drilling, the mud lubricates the bit effectively, while the mud with barite and flocculent can effectively balance the bottom pressure and prevent blowouts and kicks.

The performance and quality of the equipment is crucial to solid control technology, the main equipment of the system is vibrating screen, mud remover, degassing, desander, centrifuge, sand pump, agitator and mixer, etc. These solid control equipment is like a series of different sizes of screens, through layers of filtration to achieve the purpose of purifying mud.

The original solid control system was only equipped with a mixer and shaker, and basically no other equipment, and it was difficult to remove solid particles below 74μm. At present, the widely used integral solid control system is also equipped with cleaning equipment such as sand remover, mud remover, vacuum degassing device and stirrer, etc., to separate solid particles from 74μm to 1.5 μm step by step.

Drilling fluid cycle

The drilling fluid circulates back from the wellhead, is sent to two (or three) vibrating screens through the overflow pipe, flows into the sand settling silo after screening, comes out of the sand settling silo through the mud tank into the degassing silo, and then passes through the vacuum degasser, desander, desilter and other solid control equipment processing, and flows into the medium-speed centrifugal silo through the degassing silo, sand silo and mud silo in turn.

The medium speed centrifuge liquid pump transfers the drilling fluid in the medium speed centrifugal bin to the medium speed centrifuge, and the medium speed centrifuge drains the treated drilling fluid into the high speed centrifugal bin. The high speed centrifuge liquid pump will transport the drilling fluid in the high speed centrifugal bin to the high speed centrifuge, and finally the high speed centrifuge will discharge the treated drilling fluid to the suction bin of the mud pump. At this point, the solid phase separation of the drilling fluid circulation process is completed.

Through this solid control system, not only can more thoroughly remove a variety of large cuttings and impurities in the drilling fluid, but also can remove fine solid particles, and efficiently reduce the relative density and viscosity of drilling fluid, so as to meet the relevant requirements of the drilling process.