Drilling Mud Decanter Centrifuge

Functions of Drilling Fluids

A drilling fluid, or mud, is any fluid that is used in a drilling operation in which that fluid is circulated or pumped from the surface, down the drill string, through the bit, and back to the surface via the annulus.

Drilling fluids satisfy many needs in their capacity to do the following:

①     Suspend cuttings (drilled solids), remove them from the bottom of the hole and the well bore, and release them at the surface

②     Control formation pressure and maintain well-bore stability

③     Seal permeable formations

④     Cool, lubricate, and support the drilling assembly

⑤     Transmit hydraulic energy to tools and bit

⑥     Minimize reservoir damage

⑦     Permit adequate formation evaluation & Control corrosion

⑧     Facilitate cementing and completion

⑨     Minimize impact on the environment

⑩     Inhibit gas hydrate formation

The most critical function that a drilling fluid performs is to minimize the concentration of cuttings around the drill bit and throughout the well bore. Of course, in so doing, the fluid itself assumes this cuttings burden, and if the cuttings are not removed from the fluid, it very quickly loses its ability to clean the hole and creates thick filter cakes. To enable on-site recycling and reuse of the drilling fluid, cuttings must be continually and efficiently removed.

Types of Drilling Fluids

Drilling fluids are classified according to the type of base fluid and other primary ingredients:

①   Gaseous: Air, nitrogen

②   Aqueous: Gasified—foam, energized (including aphrons) Clay, polymer, emulsion

③   Nonaqueous: Oil or synthetic—all oil, invert emulsion

Figure1: Types of Water-Based Muds

True foams contain at least 70% gas (usually N2, CO2, or air) at the surface of the hole, while energized fluids, including aphrons, contain lesser amounts of gas. Aphrons are specially stabilized bubbles that function as a bridging or lost circulation material (LCM) to reduce mud losses to permeable and microfractured formations. Aqueous drilling fluids are generally dubbed water-based muds (WBMs), while nonaqueous drilling fluids (NAFs) are often referred to as oil-based muds (OBMs) or synthetic-based muds (SBMs). OBMs are based on NAFs that are distilled from crude oil; they include diesel, mineral oils, and refined linear paraffins (LPs). SBMs, which are also known as pseudo– oil-based muds, are based on chemical reaction products of common feedstock materials like ethylene; they include olefins, esters, and synthetic LPs.

Detailed classification schemes for liquid drilling fluids are employed that describe the composition of the fluids more precisely. One such classification scheme is shown in Figures 1 and 2.

Figure 2: Types of Invert-Emulsion Muds



written by GN Decanter Centrifuge

The majority of shale shakers use a back tank (commonly known as a possum belly or a mud box) to receive drilling fluid from the flowline.

shale shaker back tank

Drilling fluid flows over a weir and is evenly distributed to the screening surface, or deck. The screen(s) are mounted in a basket that vibrates to assist the throughput of drilling fluid and the movement of separated solids. The basket rests on vibration isolator members, such as helical springs, air springs, or rubber float mounts. The vibration isolation members are supported by the skid. Below the basket, a collection pan (or bed) is used to channel the screen underflow to the active system.

Shale shaker performance is affected by the type of motion, stroke length of the deck, and the rotary speed of the motor. The shape and axial direction of the vibration motion along the deck is controlled by the position of the vibrator(s) in relation to the deck and rotation direction of the vibrator(s). There are many commercially available basket and deck configurations. The deck may be mounted at a slope (Figures A, B, E, and F) or horizontally (Figures C and D).

various shaker basket configurations

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API RP13C Testing and Labeling Procedure

API RP 13C is the physical testing and labeling procedure for shaker screens. To be API RP13C compliant, a screen must be tested and labeled in accordance with the new recommended practice (Derrick high quality replacement shaker screen for sale). The tests describe a screen without predicting its performance and can be performed anywhere in the world. Internationally, API RP13C in known as ISO13501.

GN replacement API RP13C shaker screen for sale

GN replacement Derrick/Brandt shaker screen

The lack of commonly accepted screen labeling procedures and great disparity in screen designations throughout the oil and gas drilling industry led to the development of API RP13C.The procedure is a revision of the previous API RP13E,which was based on optical measurement of the screen opening using a microscope and computer analysis. Under API RP13E, screen designations were based on individual manufacturer test methods, producing inconsistent labeling(GN replacement shaker screen for Derrick, Brandt, MI-Swaco, etc… ).

Screen Cut Point Determined by ASTM Sieves

The API RP13C cut point is based on a time-proven testing method used by ASTM to classify particles by size. The procedure utilizes a serried of standard-size screens (sieves), which have been used for such analysis since 1910.The API standards committee simply adapted the use of these sieves to designating shaker screens.

The shaker screen designation is identified by matching the screen’s cut point to the closest ASTM sieve cut point. The cut point test uses aluminum oxide, a Rotap, a set if ASTM sieves, a test screen, and a digital scale for weighing the quantity of test particles retained by the test screen.

The D100 cut point is used for assigning screen designations.D100 means that 100 percent of the particles larger than the D100 cut point will be retained, and all finer particles will pass though. After conducting three Rotap tests, the results are averaged, and the screen is given an API number of the test sieve having the closest D100 cut point.

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In order to get efficient, high-volume processing of drilling fluids, multiple hydrocyclones may be mounted in a standalone, inline desilter assembly. GN inline desilters may contain 4” hydrocyclones varig from 6~24 pieces. They are assembled together with a common feed and

discharge manifold.

GN inline desander

GN inline desilter removes solids from 10- to 74-micron in size from feed slurry. When larger solids (40 micron and larger) are expected, the slurry should first be processed through a desander or similar equipment for removal of oversize particles.

4” Hydrocyclone Components

The hydrocyclone body is the main component of the 4” hydrocyclone. A cone tip is threaded into the bottom of the body. The soft apex is positioned in the tapered hole inside the orifice nut, which is threaded onto the cone tip. Tightening the orifice nut (turning clockwise) compresses the apex, thereby reducing the diameter of its opening. Loosening the orifice nut (turning counterclockwise) releases compression, allowing the apex to return to its normal size. By varying the opening of the apex the hydrocyclone spray pattern may be adjusted during operation.

Hydrocyclone Components

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Mud gun is designed for use in a solids control system of a Drilling Rig .It is a kind of special tools which is mainly used for mixing drilling fluids in the circulation system and prevents the mud precipitates. The structure of mud gun is simple, flexible Operation and easy for using. A mud gun is the ideal equipment to guard against precipitates in a solids control system.

drilling fluids mud gun

Mud gun is installed in a mud tank, powered by feeding pumps. Furthermore, it is usually used together with mud agitator or shear pump. They have similar configuration principle in the solids control system.

NJQ Series Mud Gun is designed and made by China top solids control manufacturer – GN Solids Control. They have 2 main models for yoru optional.

Below is the technical parameters of GN series mud gun

Model                                NJQ50-3               NJQ80-3

Diameter                           2＂（φ50）     3”(φ80)

Valve ID&pressure         0mm/3.2MPa         80mm/3.2MPa

Interface size                   2＂                       3＂

Work Pressure              ≤1.6MPa            ≤1.6MPa

Nozzle number                    3                                 3

Rotation angle                  120°                  120°

Remarks                   With manual rotation or not

written by GN Decanter Centrifuge \\ tags: drilling fluids mud gun

Decanting Centrifuge separates the suspending fluids adapting the principle of centrifugal action, the suspending fluid is pushed into the rotor drum through the inlet pipe and the fluid hole of the spiral feeder. Under the influence of centrifugal force, solid phase particles are pushed to the internal wall of the drum, then to the nud export of the small end of the drum and excreted. But the fluids is excreted from the overflow hole of the large end. Such cycle is in order to achieve the purpose of continuous separation.High speed decanting centrifuge are effective for separation.

VFD Control Panel for Centrifuge

GN Solids Control can supply different model centrifuge to meet your requirements on slurry treatment ,drilling, coring, tunneling, dredging, mining and so on. It can be used in a complete system or separately. One popular model of GN centrifuge is variable frequency drive (VFD) centrifuge GLW-V355x1250N.

GN can also make variable speed centrifuge with Atex certificated control panel and Atex/UL motor to meet the high standards of European market. Andalso, GN can adapt air conditioner for electric control panel to meet the special environment of middle east or Africa.

Below is the main specs of GN customized centrifuge:

VFD Control Panel for Centrifuge

1. Centrifuge screw complete with Tungsten Carbide Tiles
2. Centrifuge screw complete with Tungsten Carbide inserts liquid discharge ports
3. ATEX motors
4. ATEX control panel
5. Wear inserts on the liquid discharge from the centrifuge screw.
6. Cable glands to connect the motors and control panel
7. Cables to connect the motors and control panel.
8. Belt cover and collection box are stainless steel

Features of GN Decanter Centrifuge

• Southwest Petroleum University Technology Support
• High Speed up to 3200RPM & Variable Speed by frequency converter
• The main body of the decanter centrifuge made from stainless stee:SS304/SS316/Titanium Alloy
• The screw propeller and solids discharge made from stainless steel Stainless Steel protected by  tungsten carbide alloy.
• German FAG/SKF Brand Bearings
• Screw propeller & Solids Discharge Stainless Steel protected by  tungsten carbide alloy.
• Solids Liquid separation system package available
• Eletrical Components: SIEMENS/Schneider/ CHINT

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GNPJ703 mud cleaner adapts the latest designed balanced elliptical shale shaker – GNPS703.

GN uses only the highest quality materials in the manufacturing of the BEM series shale shaker and mud cleaner. GNPJ703 mud cleaner is composed of four main parts: shale shaker GNZS70-3S, desander and desilter cyclones, support bracket and base.

GNPJ703 MUD CLEANER

Main Technical Parameters

1、GNPS70-3S Balanced Elliptical Motion shale shaker

(1) Motor power：                    1.94kW+1.0 kW

(2) Vibration motor speed:             1450rpm / 1750rpm

(3) Shaker screen specification:        700x1050mm×3 (40～200mush) frame pyramid screen

2、Technical parameters of desander

(1) Diameter of cyclone:  250mm / 300mm

Quantity：1-3 pieces

(2) Inlet diameter:   6″

(3) Overflow pipe diameter:   8″

(4) Separation scale: 47μm

(5) Pressure:   0.21-0.35Mpa

3、Technical parameters of desilter

(1) The diameter of cyclone:  100mm

Quantity: 6-24 pcs

(2) Inlet diameter:   6″

(3) Overflow pipe diameter:  8″

(4) Separation scale:  ≥15μm

(5) Pressure:  0.25-0.4Mpa

Advantages of GNPJ703 mud cleaner:

SUPER G VIBRATING MOTOR

1) Produces 7.0 to 7.6 G’s of force.

2) Continuous internal oil bath lubrication system reduces repair and maintenance costs.

3) Sound output from the machines has been reduced to approximately 85 dBA.

PYRAMID SCREENS

1) Offers 105% to 184% more screen area.

2) Fluid handling capacity increases up to 125%.

3) Enables the use of finer mesh sizes at higher capacities.

DESANDERS

1) Inline manifold holds between one and three 10” desander cones.

2) Each cone can process 528 GPM.

3) Makes a separation between 47 and 56 microns.

DESILTERS

1) Customized desilter manifold holds up from 6 to twenty-four cones and accepts 4”hydrocyclones.

2) Each 4” cone can process 88 GPM.

3) Makes a separation between 12 and 47 microns.

4) Cones contain separate SS304 ball valves that can be individually shut off during operation to allow for increased control of flow capacities and ease of maintenance.

written by GN Decanter Centrifuge \\ tags: GNPJ703 mud cleaner

GN Solids Control is top manufacturer for the whole line solids control equipments. Prior to others, GN also have a factory located on Asia wire screen centre city, which solely focus on screen making.

Brandt Cobra shaker screen is one the most favorable screen models closed by GN clients, they buy Cobra replacement shaker screens from GN containers by containers. And they all said GN Cobra screen is one of their favor, they are very happy about GN screen and GN services.

Brandt Cobra Shaker Screen

Specs of Brandt Cobra shaker screen from GN:

Mesh:      20~400 (according customization)

Type:       Flat / Pyramid

Dimension:   Width: 49 5/16 inch(+/- 1/16 inch),Height:1 inch

Weight: 34 +/-1 lbs

Layer:   2 layer for ≤140mesh, 3 layer for＞140mesh

Screen material:   SS304 (Stainless steel304)

Side Rubber width:    5mm

Frame material:      Carbon steel

Why clients shift to choose GN from using UAS brand?

1) top quality with reasonable price.which enable GN screens are highly cost-effective

2) flexible leading time: compared with the extremely long leading time of American original brand, GN leading time is more short and highly competitively.

3) one stop solution: instead of finding her and there, you can find the complete line solids control equipments together with shaker screen in GN.

4) Customized services: GN can customize screens for every of your special shaker

5) More understanding of both shaker screen and shale shaker,which enable a perfect matching of GN shaker screen (Brandt Cobra shaker screen) to their shakers

If you have any question on shaker screen, or need any model screen for your shale shaker, pls feel free to contact GN:

1) You can visit GN at: http://www.gnsolidscontrol.com/

2) You can email to: sales@gnsolidscontrol.com / vivi@gnsolidscontrol.com

3) 24 hours services hot line: +86-7062282 / +86-15097534019

written by GN Decanter Centrifuge \\ tags: Brandt Cobra shaker screen for sale

GNPJ703 mud cleaner adapts the latest designed balanced elliptical shale shaker – GNPS703.

GN uses only the highest quality materials in the manufacturing of the BEM series shale shaker and mud cleaner. GNPJ703 mud cleaner is composed of four main parts: shale shaker GNPS70-3 Shale shaker, desander and desilter cyclones, support bracket and base.

GNPJ703 mud cleaner

Main Technical Parameters

1、GNPS70-3 Balanced Elliptical Motion shale shaker

(1) Motor power：                    1.94kW+1.0 kW

(2) Vibration motor speed:             1450rpm / 1750rpm

(3) Shaker screen specification:        700x1250mm×3 (40～200mush) frame pyramid shaker screen

2、Technical parameters of desander

(1) Diameter of cyclone:               250mm / 300mm

Quantity：                           1-3 pieces

(2) Inlet diameter:                     6″

(3) Overflow pipe diameter:             8″

(4) Separation scale:                  47μm

(5) Pressure:                         0.21-0.35Mpa

3、Technical parameters of desilter

(1) The diameter of cyclone:           100mm

Quantity：                        6-24 pcs

(2) Inlet diameter:                     6″

(3) Overflow pipe diameter:             8″

(4) Separation scale:                  ≥15μm

(5) Pressure:                         0.25-0.4Mpa

Advantages of GNPJ703 mud cleaner:

SUPER G VIBRATING MOTOR

1) Produces 7.0 to 7.6 G’s of force.

2) Continuous internal oil bath lubrication system reduces repair and maintenance costs.

3) Sound output from the machines has been reduced to approximately 85 dBA.

PYRAMID SCREENS

1) Offers 105% to 184% more screen area.

2) Fluid handling capacity increases up to 125%.

3) Enables the use of finer mesh sizes at higher capacities.

DESANDERS

1) Inline manifold holds between one and three 10” desander cones.

2) Each cone can process 528 GPM.

3) Makes a separation between 47 and 56 microns.

DESILTERS

1) Customized desilter manifold holds up from 6 to twenty-four cones and accepts 4”hydrocyclones.

2) Each 4” cone can process 88 GPM.

3) Makes a separation between 12 and 47 microns.

4) Cones contain separate SS304 ball valves that can be individually shut off during operation to allow for increased control of flow capacities and ease of maintenance.

written by GN Decanter Centrifuge

Function of shale shaker screen

Shale shaker screen are used for removing solids from drilling mud via passing the mud over the surface of a shaker screen. Particles smaller than the screen openings pass through the holes of the screen along with the liquid phase of the mud. Particles too large to pass through the screen are

NZS703 linear motion shale shaker

thereby separated from the mud for disposal. Basically, a screen acts as a “go-no-go” gauge:  Either a particle is small enough to pass through the screen or it is not.

Screening Surface.

Screen cloth used in solids control equipment are generally made of stainless steel woven wire, with 2 or 3 layers and in many different sizes and shapes. The following characteristics of screen cloth are important in solids applications.

Shale shaker Screen size

Correct size of shale shaker screen should be exactly the same adapt with shale shaker, neither too large nor too small. Below is the size of some most favorable screen models:

Derrick 500 shaker screen: L1050mm ×W697mm ×H46mm

Derrick2000 shaker screen: L1053mm ×W697mm

NOV Brandt Cobra screen: L25inch ×W49 5/16inch ×1inch

MI-Swaco Mongoose screen: L1165mm ×W585mm ×H40mm

GN-shaker-screen

China top manufacturer - GN Solids Control is also a specialist for solids control items or high quality replacement shaker screens. For more information on shale shaker or solids control items, please feel free to contact GN.

written by GN Decanter Centrifuge