Drilling mud system

GN Solids Control makes Mud Recycling System and desanding plants for construction Trenchless Engineering Companies, like for HDD (horizontal directional drilling), TBM (Tunnel Boring Machine), Microtunnelling, piling, etc…

GN Solids Control has more than 10 years of experience in the design and manufacture of mud recovery systems, especially in trenchless projects with multi-function and compact design to cater for different demands and applications from clients. According to the different requirements from users, and jobsite situations, GN Solid Control can provides different configurations of mud recovery system and desanding plant to meet the requirements of different working conditions. There are usually two types of mud purification systems suitable for trenchless construction: one is sand removal unit with cyclone purification system, we usually call it desanding plant. And the other type of design is self-contained mud recovery system.

The desanding plant with hydro cyclone purification system occupies a small footprint, and is economical and affordable. The system is composed of a hydrocyclone and a double deck shale shaker, both of which are installed on a small mud tank. The sand removal cyclone purification system is a two-stage separation device, and its function is to remove coarse particles from drilling mud. The desanding plant is mainly used in projects that can accept larger particle size solid drilling mud, such as Microtunnelling, piling, and so on.

The high standard self-contained mud recovery system developed by GN Solid Control is composed of four stage separations: shale shaker for coarse cuttings separation, 10 inch desander cone separation, 4 inch desilter cone separation, and decanter centrifuge for ultra-fine solid separation. The mud tank of the self-contained mud recovery system has a bigger storage volume to store the purified drilling mud. At the same time, it also has more tank surface space to arrange more separation equipment. Customer can also choose a centrifuge to reduce the ultra-fine solid in the drilling mud and to avoid the enrichment of the ultra-fine solid phase in the drilling mud.

GN Solid Control not only has a standard sizes of mud recycling system and desanding plant, but also provides custom-designed mud recovery system to meet for different demands.

This week, a batch of solids control equipment was dispatched from GN Solids Control. The equipment will be used in Chinese rig site for a drilling rig mud circulation system.

It is a set of full package solids control mud processing equipment including below equipment:
1) 2 sets of linear motion shale shaker: GNZS703F. It is a 3-panel shale shaker for drilling mud pre-separation.
2) 1 set of desander mud cleaner, model GNZS752F-2S. The desander mud cleaner is equipped with a big under flow shale shaker the same model with first stage solids control shale shaker. It is easy for clients to stock spare parts and replacement screens for both shale shaker and mud cleaner.
3) 1 set of Desilter mud cleaner, model GNZS752F-12N. The desilter mud cleaner is equipped with the same under flow shale shaker with first stage solids control shale shaker and desander mud cleaner.
4) 2 sets of Decanter centrifuge, model GNLW452. It is a economic standard middle speed decanter centrifuge for barite recovery.
5) 2 sets of mud tanks.
6) 1 package of jet mud mixing system.

Besides the mentioned equipment, GN Solids Control is also capable to make drilling mud agitator, mud gun, centrifugal pump which are fully interchangeable with international popular brand, other VFD centrifuges, FHD decanter centrifuge, Vertical cuttings dryer, high G dryer, screw conveyor, and various model replacement shaker screens for different brand shaker models.

GN VFD decanter centrifuge is with advantages for self-protection and smart control.
The LPC program of GN hydraulic centrifuge is with below self-protection functions:
The start/stop of the hydraulic centrifuge and the start /stop of the centrifuge feed pump are logical connected for protection.
1. After start the centrifuge, only after the centrifuge bowl achieve the preset speed and running for some seconds, the feeding pump can be started for feeding mud.
2. When the decanter centrifuge is stopped, feeding pump cannot be started.
3. During the centrifuge running, the centrifuge will not be cut off if directly press the centrifuge stop button. Only by pressing the stop button of the feeding pump and stop the feeding pump, and then the centrifuge can be powered off.

Mud agitator is one of the most popular equipment for drilling mud systems. It is mainly used to keep both the mud uniformity and the suspension of solids. The mud agitator is used to agitate the mud consecutively and reliably. This agitator agitates the mud to make the cuttings silt and sand pass the solids control system without being precipitated onto the tank bottom.

According to the different types of gearbox design, the mud agitators can be divided into 2 kinds:
The most popular design is worn and gear reducer mud agitator.

The worn and gear reducer mud agitator is an economic standard mud agitator. The mud agitator is equipped with explosion proof motor, worn and gear reducer. The worn and gear reducer is working stable and cost effective. It is also easy for maintenance.

Another kind of agitator is equipped with heavy duty helical bevel gearbox. We call it helical bevel agitator.

The mud agitator is equipped with heavy duty helical bevel gearbox. Compared with traditional worn and gear gearbox, the helical bevel agitator is with a bigger torque. It is more powerful for heavy mud. The heavy duty helical bevel mud agitator save also power, for the same motor power, the helical bevel mud agitator is with a big torque compared with worn gearbox. So a smaller power helical bevel mud agitator can reach the performance of a bigger power worn gearbox agitator.

There are 2 ways for the connections of motor and agitator gearbox.
The motor and gearbox can be connected by flange directly. It is with small footprint.
The motor and gearbox can also be connected by coupling, and fixed on the small skid. Clients can choose the suitable one per his job site situation.

Other accessories for drilling mud agitator:
1) Shaft: The shaft length of mud agitator should be customized per clients’ mud tank size.
2) Impeller: There are double layer and single layer impeller for mud agitators. The impeller size is also designed to suit for the tank depth and width for a better agitating performance.
3) Tank bottom stabilizer to fix the shaft. For mud tank depth over 1800mm. GN will recommend Tank bottom stabilizer to fix the shaft and avoid is swaying during rotating.

A few weeks ago, GN Solids Control had a shipment for some solids control equipment to a client in Uzbekistan. Soon, the equipment will be used in extreme cold regions of Uzbekistan. The lowest ambient temperature in the area can be below minus 50 degrees Celsius.

This is not the first time that GN Solids Control has sent equipment to the extremely cold regions of the Commonwealth of Independent States (CIS).  4 years ago, in 2014, some package of drilling cuttings drying system was dispatch to Baker Hughes in Russian. The systems were running from 2014 till now. End users are very happy with GN products quality and GN services. Since they have other Chinese brand equipment in other jobsites, after comparison, end users said GN vertical cuttings dryer and decanter centrifuges are the best from China.

The solids control equipment will be used in clients’ drilling rig mud system for mud processing, the shipment is including following processing equipment:
1) Some linear motion shale shakers. It is the first stage solids control equipment in drilling rig mud system.
2)Some Mud cleaners. In rig mud system, mud cleaner is used after shale shaker. The desander can clean the mud to 50 microns, while the desilter separator can separate the drilling fluids to 27 microns.
3)Some Decanter centrifuge. There will be at least 2 sets decanter centrifuges in a complete drilling mud processing system. Firstly, a middle speed decanter centrifuge at 1800 rpm will be used to recovery the barite. After some circulation, there will be too much ultra fine solids inside the drilling mud, a high speed decanter centrifuge can be used to reduce the mud weight.

Furthermore, GN Solids Control is with rich experience to offer processing equipment for high temperature areas in Middle east and Africa, like in UAE, Kuwait, Iraq, Qatar, Yemen, Oman, Saudi, Algeria, Egypt, Ukraine, etc…In these areas, the highest temperature can up to +55 degrees Celsius. GN Solids Control is capable to make solids control and drilling waste management equipment for cold temperature areas to minus 50 degrees Celsius and to high temperature areas up to +55 degrees Celsius.

Recently a customer has some questions about GN Electric Ignition Device. They contacted GN people and GN replied. Below are the major communication between GN and operator of the ignition device.

Client’s Questions 1: I presume the solenoid valve will close once the ignition is activated or should we close it on remote. This is for preserving the gas for future use. ( we may have to ignite several times during well kill operation as we get gases intermittently-H2s Laden gas)
Reply from GN Solids Control: Once you start up the igniter and it is firing stably, the solenoid valve can be closed for saving gas. As the gas tank is small size. It is only 5kg. You can ignite again in case you need with the wireless controller.

Client’s Questions 2: As the vent line is from the top of gas buster and then connected to the igniter which will be about 6 to 8 ft high. This forms a “U” section for the vent line and liquids remaining cannot be cleared out, which gives resistance for any gas vented out and blow back into gas buster. Any solution for this. Any bypass is recommended to drain out these fluids?
Reply from GN Solids Control: What kind of gas buster you used? Mostly, the igniter is connected to mud gas separator. The vent line on top of the mud gas separator. Liquid is impossible to go inside.

Client’s Questions 3: As the igniter is kept in open position, we may also end up with sand and also rain water ( in deserts) inside the igniter. Can we intermittently flush the system with water. Is it safe for the system electrics. In case we flush, then we will definitely have a reservoir of water in the vent line and adding up sand will only plug the system.
Reply from GN Solids Control: You do not need to flush the igniter. It will not be blocked. There is a screen on top of the Igniter burner pipe to prevent big sizes blocks or stuffs fall inside.
There is a drain port with ball valve (JB/T 308 PN16DN20QB) at the bottom point of the Igniter elbow connection pipe. You should open the ball valve to drain the pipe timely to release sands/rain.

Client’s Questions 4: What would you recommend to avoid getting into critical situations at the Rig.
Reply from GN Solids Control: If you will not use the Igniter for a longer time. It is better to close all valves, and cover the Igniter burner with rainproof cloth or plastic bag, to prevent it from rain/sands.

GN Solids Control makes different sizes of decanter centrifuge:

1) The 9 inch mini size decanter centrifuge: GNLW223, GNLW224 series. It is mainly for waste water and mining industry separation.

2) The 14 inch most popular size decanter centrifuge: GNLW363 series. The size is widely used in oil and gas drilling and for industry separation.

3) The 18 inch big bowl centrifuge for bigger capacity: GNLW452 series low speed big bowl and GNLW453 series high speed centrifuge.

4) The 22 inch big bowl centrifuge for waste management and industry waste application: GNLW553 and GNLW554 series

5) The largest size GN Solids Control does make is 30 inch: GNLW764 series.

GN Solids Control offers different design for centrifuge driving systems: fixed speed motor drive system, variable frequency drive system (VFD centrifuge), and full hydraulic drive system (FHD centrifuge). No matter what kind of driving system, GN Solids Control will include the pump driving control inside the centrifuge control panels.

But sometimes, clients want to use their existing pumps, if they use the pump control inside GN centrifuge control system, it will be fine. In some cases, clients use their old pump control panel with their own pump. In will cause overload of the centrifuge. It is not recommended. Why the centrifuge feeding must be inside the centrifuge control panel?

There is safety protection inside the centrifuge control system. If the pump control is related to the centrifuge control (main motor drive and back drive motor), in case the centrifuge is overload, and the current will be increased. When the current increase over the setup data, centrifuge control system will adjust its control: to reduce the pump speed to reduce the feeding. When the pump feeding capacity to centrifuge is smaller, the current increasing will be reduced. When the current drop down to a setup safety data, the centrifuge control system will increase the pump speed to increase pump feeding, the centrifuge can handle a bigger capacity that it can do.

If clients want to use their own pump to feed the centrifuge, it must be for sure to relate and interlock their pump control to the centrifuge control. It can avoid overload and protect the centrifuge well.

Vertical rotating drilling rig is the normal machine used in piling project. During the drilling process, in order to protect the inner wall of the drilling hole and speed up the process, the operator always chooses to use drilling mud. Then here comes another problem how to reduce cost of the drilling mud thereby to reduce the cost of drilling. The solution is to use mud recycling system to make the drilling mud reusable.
The purpose of the mud recycling system is to remove the large size solid particles in the drilling mud by several separation machines. In regards to the mud recycling system for piling project, it could be a very compact design as separation process is not so complex as that for oil gas drilling. GN solids control is one of the most experienced separation solution providers who could provide the mud recycling system for almost all the industries will use it. GN already developed the standard mud recycling system especially for the piling project.

gn-de-sanding-unit-piling

De-sanding Unit

Strictly speaking, the mud recycling system used in piling should be called de-sanding unit as the drilling depth is normally shallow and most of the solid particles are sand. A de-sanding unit would be enough for processing the separation to get the expected reusable drilling mud.
GN’s de-sanding unit is a compact structure 2 steps separation system. The main equipment in this de-sanding
unit is combined with a 2 layers shaker and cyclone manifold. The double layers shaker is used for coarse solids separation by the under layers and the upper layer screen is for drying the slurry discharged from the cyclone unit. The tank under the shaker unit is used to store the drilling mud. One centrifugal pump is installed in the system for transferring the mud to the cyclone unit for sand separation.
This de-sanding unit could be connected with extra mud tank for larger capacity mud storage. The operators can also equip a jet mixing unit to make an self-contained mud recycling system for other drilling project like HDD and water drilling.

Mud system will not work if there are no mud tanks. In the mud recycling system, the tanks are used to store the drilling mud to be a base where the solids control equipment to be installed. Normally, more than one mud tanks
will be used in the oil drilling mud system. For different purpose, the design of the mud tank is different, especially the inner structure of the mud tanks.
There are mainly 3 types of mud tanks recycling tank, intermediate tank and premixing tank. Then what are the different among these 3 types of mud tank?
The recycling tank is where to install the primary shakers and degasser unit, and also the de-sanding and de-silting unit. Each of equipment needs a compartment in the mud tank. As the recycled drilling mud is treated by the solids control equipment one by one. After treatment by each of the equipment, the drilling fluids will be cleaner than before. Thus the drilling fluids cannot be mixed. The wall between two compartments always has an overflow port for balance of the drilling mud in the tank.

Mud-Tank-for-ZJ-50

Mud Tank System

For the tank to install the de-sander and de-silter unit, inner structure of the mud tank would be much complex as there are pipes for centrifugal pump to such the drilling fluids from inside of the tank and transfer to the cyclone for further treatment. Operator has to know which pipe is for de-sander and which pipe is the desilter.
On the mud tanks for installing the solids control equipment on, there always have the walkways and handrails. The walkways provide enough space for the operator to walk around the equipment for operation and maintenance. Intermediate tank is a type buffering tank, part of this tank is for mud recycling, and other parts are used for mud storage. Operators can easily tell how many compartment in this tank.
The premixing tank is used to mix drilling fluids. It always is connected with the jet mixer unit. The mixing pumps suck liquid from mud tank and send liquid back again with added mud materials from the hopper. Thus the pump should be able to suck the drilling mud from anywhere in the mud tank used for mixing and storage.
Therefore, in the mixing tank, there are two groups of pipelines, one for sucking, and the other one is for sending liquid back. Mug agitators and mud guns are always installed on the mixing tank.
Though, the inner structure of the above tanks is different, the outer dimension and design are always the same for purpose of easy transportation and assembling.

Normally, the drilling mud recycling system is consisting of mud recycling tank skid and mud mixing tank skid. On
the mud recycling tank skid, the solids control equipment like shakers, mud cleaner, and even decanter centrifuge unit will be installed for removing the cuttings and useless solid particles in the drilling fluids. After several times recycling, the useful mud materials will loss together with the cuttings, and then the mud engineer need add new mud materials into the drilling fluids to maintain the proper mud property for the drilling job. The mud mixing unit is the equipment used for adding the mud materials into the fluids.

gn-mud-mixer-unit-1

Mud Mixing Hopper

What is the Function and Principle of the Mud Mixing Unit
The mud mixing unit is always installed at end of the mixing tank. Before starting the drilling, the driller need have sufficient drilling mud to keep a continuous drilling. Thus at the first, the mud mixing unit is used to make the drilling mud by mixing clean water and mud materials. With the drilling going on, once the mud property is not proper for the drilling process, new mud materials like barite or other polymers need to be added into the drilling fluids. The mud mixing unit is sucking the drilling mud from the mixing tank, and then pump the mud together with materials back again into the mixing tank. Normally, the mud agitators would be equipped on the mixing tank for fully blending.

What Components are Included in the Mud Mixing Unit
1. Centrifugal Pump – the inlet of the pump is connected with the mixing tank for sucking the drilling mud from tank. And the outlet is connecting with pipe manifold that will transfer the mud to the hopper unit. As this pump is fixed with the mixing hopper, it is also called mixing pump. This pump is driven by an electric motor via direct shaft connection. By higher efficiency shearing purpose, GN will used belt driving for a shearing pump.

gn-mud-mixer-unit-2

Mixing Hopper Bag Breaker

2. Mud Hopper – GN’s mud hopper is Ventri type connected with the pipe manifold via a T pipe. The mud materials will be added into the hopper and then immediately sucked into the drilling fluids as there is a vacuum produced by the high speed flow. For the hopper, GN uses the material of stainless steel for better anti corrosion performance and long life time. Inside the hopper, there is a bad beaker for quickly adding of powders. On the pipe manifold, there is a pressure gauge for the operator to inspect the working pressure of the mixing pump.
3. Control Panel – GN’s mud mixing unit is equipped with explosion proof control panel for application in Zone 1. The operation of the control is easy for only three buttons on the panel. One on, one off and one for emergency stop, accordingly, the signal lights is installed to reflect the operation.

GN’s mud mixing unit could be installed both at the end of the mixing tank or separately mounted on a small skid. This mud mixing unit can also be designed as a dual hopper dual pump type for larger capacity or in case one of them is broken down.

The persons who know solids control equipment may know well on the shale shaker and mud cleaner unit. These 2 machines are very common in solids control system that do solids separation job from the first to forth stage. The shale shaker is located at the very beginning of the mud recycling system for primary solids control; the coarse cuttings could be removed by the shale shaker. While after treated by the shale shaker, the drilling fluids would be transferred to the mud cleaner for further treatment.
For the purpose of easy maintenance, in the same solids control system, the mud cleaner is equipped with under drying shaker that is same model as the primary shale shaker. Mud cleaner is just a machine on which the cyclone frame was fixed above. The mud cleaner unit is only able to be used to separate the solids via the hydrocyclone units. Why the mud cleaner unit cannot be used as a shale shaker even if it has the under drying shaker? This is really a good question. GN’s engineer equipped a logging tank to the mud cleaner unit and the mud cleaner unit becomes a shale and mud cleaner composition unit.

gn-shaker-cleaner-unit

GN Shaker & Mud Cleaner Composition Unit

Normally, GN’s shaker unit has back type logging tank that is used to collect the drilling fluids coming out from the drilling hole. The drilling fluids accumulated in the logging box firstly and then overflow into the shaker deck, thus the shaker screen will not be damaged by the high pressure drilling fluids. This unit could be used as a shale shaker unit.
De-sanding and de-silting cyclone are installed on the mud cleaner for finer solids separation. The solid discharged out from the bottom nozzle of the cyclone also has high pressure that will shorten the screen life if directly dropped onto the screen surface. To avoid this situation, there is a hopper collection box that is used as buffer between the cyclone and screen. To make this machine compact, GN’s engineer designed to insert the buffer box into the logging box, which means the logging box is also used as second buffer box for the cyclone unit. This is the function of mud cleaner.
One thing need to be noted is this shaker and cleaner machine can only be used for one function one time: either shaker or mud cleaner. This is a cost saving unit with small footprint, for some project not very urgent, this unit could be a very ideal choice. GN ever showed this unit at Beijing CIPPE, much attention was attracted there.