Monthly Archives: February 2022

Solids Control System for Drilling Mud

As we all know drilling mud is one of the most important middle material in the drilling program. As usually ,The solid control system refers to the degasser, shale shaker, desander, desilter, micro desilter, desanding and cleaning device, desilting cleaner, centrifuge and mud tank. That is a whole set of system according to the requirements of solid control. The selection of solid control system is mainly based on the following principles
1 ,Type and size of particles to be removed or suppressed
2,Cost of drilling fluid
3, Liquid solid cost ratio of drilling fluid
4. The quality of drilling fluid that needs to be maintained during drilling is poor, and environmental factors are taught
5, freight and other miscellaneous expenses;
6 ,density of drilling fluid used;
7, mechanical ROP, solid removal rate and circulation rate.
20170704 Oil Sludge Treatment 1
Select the suitable solids control equipment will help to reduce the drilling cost and improve working efficiency.
There are seven basic systems for solid phase control. The first system is the most basic, which is suitable for non weighted drilling fluid. The system largely rely on desander and desilter. During fast drilling, the desilter should be started continuously. It should be noted that if we can concentrate the drill and make it more concentrated than the diluent, we can use “low-density drilling fluid” for the desilter. The second system added Decanter centrifuge based on the first solids control system. Decanter centrifuge are used to remove out the tiny particle. It can clean mud and also reduce mud gravity. The 2 system are used in most drilling project. However , in some special project, the system will require several units hydrocyclone and Decanter centrifuge to teat expensive drilling mud to recycle the mud as much as possible.
However, shale shaker, degasser, desander, desilter, decanter centrifuge are the basic solids control equipment. GN can provide all these equipment and customized produce the system according to client requirement. If you have demanded, welcome to contact us.

Drilling Particle Introduction

In solids control project, the solids content and particle size both are the most important data for user to select suitable separation equipment. And the include particle will also effective the drilling efficiency. Different working condition will generate the different size particle. Today we will introduce the different situation of particle generation.

The range of particle sizes taken into the mud stream at the bit will depend mainly on:
Formation hardness Bit type;Chip hold down; and Effectiveness of the hydraulic hole cleaning action. Even if adequate hydraulics are being used and chip hold down or differential pressures normal, in hard formations fine chips will usually be generated. Most of the particles are finer than 22 microns. Another reason for fine chips is the bit type..a diamond bit will generate smaller chips than a rock bit in hard formations. Use of a water base mud will result in smaller chips than oil mud because of hydration and dispersion effects of the aqueous system. Use of a water base mud for drilling a soft shale formation will ordinarily result in very fine cuttings. With an oil mud and a cone bit, most of the cuttings are larger than 30 microns. Use of a PDC bit will produce cuttings which are typically much larger.The particle size distribution is also affected by mechanical degradation. As the particles are circulated up by the mud return system, they are mashed and ground. The corners are broken off, so that continually smaller and smaller particles are being generated.Borehole stability is a factor affecting the mechanical degradation of formation solids brought to the surface by the mud system. If the hole is enlarged by erosion or sloughing.cuttings cannot be lifted from the hole efficiently. Low annular velocity in the enlarged sections of hole will cause cuttings to fall back and be ground to a finer size before reaching the surface.

shale shaker

shale shaker

In actual project, there are many reason generate vary size particle. The accumulation of solids will reduce mud property. Select the suitable solids control equipment to remove out the solids is very important to keep mud property.

Centrifuge Classification

Centrifuge has widely application on different industries, such as chemical industry, energy ,environment, beverage. All centrifuge utilized the centrifuge force generated under high rotated speed. Whatever decanter centrifuge, disc centrifuge or tube centrifuge. Today, we will classify the decanter centrifuge through the separation purpose. In generally, there are totally 3 types separation , dewatering, clarification, and separation. Dewatering is to remove out the liquid phase in the solid phase, and clarification is to remove the solid phase in the liquid phase. Concentration is to make solids in the solution increases.

Decanter centrifuge

Decanter centrifuge

Dewatering is to remove out liquid from solid as much as possible. As usually, user want to get the discharged solids much dryer much better. To reach this target, the sludge need to stay more longer time inside centrifuge bowl, and solids content of discharged liquid is high relatively speaking. The cone angel was designed smaller to speed liquid discharge ,and make solid phase stay longer time in side centrifuge. Totally opposite with dewatering centrifuge ,clarifying centrifuge require to bigger cone angel as much as possible. Big cone angel will increase the length of liquid processing section, which can make the liquid stay longer inside centrifuge. User usually can get the clean liquid and wet solids. Except the above both types , separation centrifuge make it balance for discharge solids and liquid. Cone angel is in the middle between dewatering and clarify.
The cone angel of centrifuge decided the application of decanter. So when we select centrifugal model ,we need to clear what purpose we want, what treating capacity you need, and also the solids content. The centrifuge capacity is depend on the solids content of material. High content will reduce capacity. Except this, we also need to pay attention to bowl material. As usually ,centrifuge use the high strength stainless steel such as SSR 205,316L. When process slurry with chloridion , make sure the chloridion content is below the Limit, otherwise it will corrosive steel ,and damage it.