Drilling mud system

Few months before, GN got order of 4 pieces decanter centrifuges from one Africa drilling company, after the jobsite actual operation, they placed the repeated order of 6 pieces decanter centrifuge. Many of the GN’s customers are this kind of old customers. A certain percentage of GN’s business is coming from the old customer who is satisfied with GN’s equipment performance.

This total 10 Sets decanter centrifuge are all package provided with the feed pumps. While for the centrifuge, there are both the fixed speed model of GNLW363BG and the variable speed model of GNLW363BG-VFD. The feeding pump is provided as a package solution for the customer; it is also an option for the customer.

GN Decanter Centrifuge

GN Decanter Centrifuge to Africa Drilling Company

The parameters of the centrifuges and feeding pumps are as below:

GN’s fixed speed centrifuge is designed typical speed of 3200 RPM, while maximum speed is 3900RPM. And there are different belt pulley for option and could also be package provided, the belt pulley are 2500RPM and 2200 RPM. The variable speed model could be adjusted from 0 to 3200 RPM. GN’s 363 series decanter centrifuge is designed bowl diameter of 14 inch and bowl length 50 inch which is very popular used in the drilling mud solids control and waste cuttings proposal processing. The treating capacity of 130 GPM could meet the general application demand on site.

GN always recommends the feeding pump for the provided centrifuge. The pump proposed is positive displacement type screw pump. The main material of the pump is stainless steel of SS316L that make sure a long life time and better feeding performance. The gearbox used for this pump is from Germany Nord. The capacity of 30 cubic meters per hour is matched to the treating capacity of the centrifuge.

GN’s decanter centrifuges are more and more used in the jobsite of drilling company worldwide. It is the stable performance won the customers trust and got the repeated orders for GN Solids Control.

GN’s drilling mud recycling system is always equipped to the drilling rig and provided together to the end user. Just like the China domestic rig manufacturer of SJ from Sinopec and RG from CNPC who always get the drilling mud recycling system from GN solids control to equip with their drilling rig, the provide to their customer together. Not too long time before, GN finished on set solids control system for 750 HP drilling rig for Sinopec SJ’s Turkey project.

GN 750HP Rig Mud System

GN ZJ30 Rig Mud System

750 HP rig in China would also be referred as ZJ30 which could drill to depth of 3000 meters. The drilling mud recycling for this rig is configured as below:
4 units’ mud tanks systems include 1 recycling tank, 2 active mud storage tanks and 1 mixing tank. On the first tank for sand trap, there is also a compartment used for trip tank. When the drilling pipe need to be pulled out and changed, the drilling mud in the trip tank compartment would be pump back to the drill hole for protecting the well wall and keep stable downhole pressure.
This mud recycling system is a 3 stages design with shale shaker, mud cleaner (de-sander & de-silter). 2 units of GNZS703E-HB shale shaker have the total capacity of 240 cubic meters. The customer could adjust the feeding rate to each of the shaker by getting a flow divider. 1 unit of mud cleaner is with 2 pcs 10” de-sander cyclones and 12 pcs 4” de-silter cyclones.
On the mud storage tank, the mud agitators and mud guns would be equipped to prevent the solid particles sedimentation down to the tank bottom. Each tank would be equipped 3 units agitator and mud gun.
This system adopts the 55kw centrifugal pump for transferring the mud to the hydrocyclones and the mixing pump is the same model as consideration of future easy maintenance and repaire. The trip tank also is equipped with trip pump for pumping the mud back to the downhole.
All the electric parts like the motor and control panel are explosion proof standard especially for application in oil drilling ndustry. GN could provide complete line for oil drilling rig mud recycling system ranging from 350HP to 2000HP, welcome for contact on the inquiry and solution.

The drilling fluids is nowadays widely used in drilling projects and under the strict regulation on environment protection, how to minimize the discharge of environmental hazardous waste solids and maximum the drilling fluids recovery is the mainstream topic among the industry.
The using of mud tank to store the drilling fluids coming back from the drill well has been widely accepted and recognized by all the drilling contractors. Without digging a mud pit on the ground greatly reduce the pollution to the soil. Especially for some limited job area, the mud tank would be the preferred choice for drilling fluids. The using of the various kinds of the solids control equipment highly speeds up the separation of solids in drilling fluids.

GN Drilling Waste Cuttings Dryer

GNCD930 Cuttings Dryer

The closed loop drilling mud solids control system, if complete configuration, will include 2 parts. Drilling mud solids control and waste drilling cuttings treatment. The purpose of this 2 parts is same for minimize the discharge of environmental hazardous waste solids and maximum the drilling fluids recovery.
For solids control, after treated by the shale shaker, desander, desilter, even the decanter centrifuge. The ultra fine solids particles would be removed out from the drilling mud, and then active mud could be re-used.
The waste cuttings treatment part is functioned to recovery as much as possible the drilling fluids and make the cuttings dry enough for easy transportation to further environmental friendly treatment process. The cuttings out from the solids control shale shaker and desander, desilter would be transferred to drying equipment first. The drying equipment would be different according to water base mud or oil base mud is used. A high G force drying shaker would be better for water base drilling mud cuttings. The Verti G cuttings dryer, e.g. GNCD930 cuttings dryer could be used for both the water base and oil base cuttings drying. The drilling fluids out from the drying equipment would be pump into high speed decanter centrifuge for ultra fine solids separation.
By doing so, the drilling fluids would be maximum recycled and no discharge to outside of the tank system. The discharge drilling cuttings is dry enough for further treatment. Greatly guarantees the environment protection and high working efficiency.

Oilfield operation need various electrical equipment like control panels, electrical motors and so on. All these electrical equipment performing well make sure the entire project job done well. But the most import is a safe working environment on the oilfield as there is the risk of explosion any time during oilfield operaton.

oilfield cuttings dryer

Oilfield Cuttings Dryer

As per the define of the IEC (International Electrotechnical Commission), the explosion working environment is classified as gas explosive and dust explosive. When we talking about the explosion proof standard electrical equipment, we are talking about the equipment used in the various gas explosive working environment. And then according to the existence time of the gas explosive, the working environment is classified to 3 zones as below:
1. Zone 0 – Under normal operation condition, the gas explosive exists continuously. Always more than 1000 hours per year.
2. Zone 1 – Under normal operation condition, the gas explosive exists sometimes. More than 10 hours buy less than 1000 hours per year.
3. Zone 2 – Only under abnormal operation condition, the gas explosive exists. Always less than 10 hours per year.

The Zone 0 always represents some airtight space such the gas storage tank. On the oilfield, the Zone 1 represents the area around the drilling rig. And the area which includes the space for mud recycling system, mud pump, water tanks and other drilling field equipment. As per the minimum ignition power required, the gas explosive are classified as 4 degrades separately Ⅰ,ⅡA, ⅡB, ⅡC. This classification can also be treated as the equipment group. The equipment used in group Ⅰ is for mining industry. Group Ⅱ is for other industry working environment. The equipment used in group ⅡC can also be used in ⅡA, ⅡB which means the equipment in Group ⅡC has a higher explosion proof level.
GN could provide the solids control equipment with motor and control panel explosion proof certified. The explosion proof level is ExdⅡBT4 which could meet the demand of gas explosive Zone 2.

Drilling fluids is now widely used in oil, gas drilling and other drilling projects. By using the solids control equipment, the drilling fluids could be recycled many times for cost saving and environment protection. This article would give a simple introduction on the function of the drilling fluids.

GN Drilling Fluids Recycling System

GN Drilling Fluids Recycling System

What is the function of the drilling fluids

1. Flushing bottom of the well – the high pressure drilling fluids get out from the drill bit would flush the bottom of the well then make no obstacles for drilling process.
2. Carry cuttings – the drilling fluids would take the drilling cuttings out to the ground surface for mud cleaning process.
3. Balance formation pressure – due to very deep drilling, the drill bit may go through different formations such as rock formation and ground water formation. The drilling fluids here functioned to prevent the ground water getting into the drilling well. This would protect the geological structure.
Besides, the drilling fluids could also function to cool down and lubricate drill bit, protect borehole wall and provide downhole power.

To fully obtain the drilling fluids advantages, there are several requirements on the drilling fluids.

1. The drilling fluids should meet demand for drilling mud recycling
Drilling cycle request the drilling fluids low pump pressure (low fluid viscosity), excellent ability to carry cuttings (dynamic force is high), low starting pump pressure (low static shear force), good lubrication performance, low friction (less solids particles)
2. Maintain the stability of borehole
It is requested to use drilling fluids column to balance the formation pressure. And when drill oil and gas layer, the drilling fluids is also needed to balance the pressure of the oil and gas. That would request a stable density of the drilling mud.
3. Oil and gas protection
After drilling oil and gas layer, drilling fluid contacts with oil and gas. To prevent drilling fluid damaging the oil and gas layer, the drilling fluids should be small filtration, thin mud cake, low solid content and low filtrate of hydration etc.
4. Protect the nature environment
Drilling fluid often contains oil and crude oil, diesel oil and a large number of chemical agents. In order to prevent the possible impact on nature environment, non-toxic, harmless drilling fluids should be used.

It is known that the solids control system is part of the complete drilling rig system. So, always we see the drilling mud solids control equipment is equipped for the drill rig at wild field where the working condition would be various. Some places the weather is four-spring like, while some other places very cold. When finished the drilling job at one well, all the equipment would be disassembled and transported to next well. It always takes few months to move all parts of the drilling rig system. Solids control system is only small part of the drill rig system. However, if the solids control equipment could be moved easily, that would be also benefit for the whole transportation of the drill rig.

GN decenter centrifuge installed in frame

Decanter Centrifuge Installed in Frame

With the rich experience on solids control management and job working, some customers came to GN Solids Control and talked about their idea to build a drilling mud system which could be easily transported and all equipment could be operated and repaired indoor. What they preferred are two options: Containerized and Frame Supported.

For the containerized design, all the equipment would be located inside a container or a same size mud tank, which is completely closed and with doors for operator in and out. The advantages of this design the all operation would be completed indoor, especially for some area with bad climate condition. With air conditioner installed inside the container, winter to prevent cold and summer avoid hot sun. On the other hand, this containerized design may not have sufficient space left for the operator to move do maintenance job freely. For the big size equipment, it is also difficult to be put into the container. Once GN provided Russia customer 2 units containerized drilling waste cuttings management system. To lift out the huge cuttings dryer out from the container, the container was opened a door on top and use a crane to get the rotation part of the dryer out.

For the frame supported idea, the solids control equipment like shale shaker and decanter centrifuge would be installed in a strong steel frame, the frame size is same with standard container. When assemble the system, the equipment could be easily positioned. For the operation and maintenance, there is enough space as there will be walkways surrounded the frame. The operator could make a thick canvas cover to cover the whole system to make it a closed unit.

Both the containerized and frame supported system are easy for transportation as no equipment need to be disassembled before moving. The frame is design same fixing point with the container that makes the system trailer available.
Welcome contact with GN Solids Control to get a solution for drilling mud recycling.

In last article, we gave a brief introduction on how GN layouts the mud suction and mixing pipeline in the mud circulation system. On the mud tank, there are also other functional pipelines that would be designed and laid properly for complete the mud circulation system utility and enhance the working efficiency. Today we would like to gave a explanation on how GN engineer team design the mud gun pipeline and cleaner water line.

GN Drilling Mud Gun

GN Mud Gun with 3 Nozzles

What are the Functions of the mud gun line and clean water line

It is well known that in the mud tank, the mud agitator would be installed to agitating the drilling mud to prevent the solids particle sedimentation down to bottom of the mud tank, thus the drilling mud would be transferred or flow to next stage process as the suspension form. That would be benefit for subsequent equipment to work on the drilling mud. Mud agitator is high efficiency device. However, the mud agitator still can not get to the dead corner of the tank inner. For the issue, the solids control engineer always use the mud gun to solve the problem, the mud gun would be injected with drilling mud, high pressure mud out from the mud gun nipple would be jetted to the mud tank corner, by adjusting the angle of the mud gun, almost all the corner would be reached. During the mud recycling operation, the spraying mud would defile the equipment and lead to low efficiency. Moreover, the drilling mud would loss when separating. The mud engineer would have to add water into the mud tank to mix new drilling mud. The laying of the clean water pipeline would be necessary for these purpose, it should be very easy for the engineer to get the water.

How GN design the mud gun line and clean water line

GN’s mud tank are always rectangular, the top of the tank structure is applying the 4” tube steel. GN’s engineer would used this tube steel as the channel of the drilling mud and clean water. Only the seamless steel tube would be chosen in case of leakage of the liquid under high pressure. The mud gun line would be laid on every mud tank in the mud system so that the mud could be transferred to every mud tank compartment. Always, the mud gun line would occupy 1 length and 1 width of the tank top structure steel tube, between different tanks, the mud gun line would be connected by hose. To avoid confusion, the mud gun line would be laid at same side of the mud tank, while the clean water line is chosen as the counter sides.
The mud gun is installed inside the mud tank, thus the opening of the mud gun line would be inner the tank for easy connecting with mud gun terminals. While, the clean water line has several opening on mud tank top surface, the mud engineer would connect the water line by using a tap and control by a valve.

Regarding the power, the mud gun line is connecting with the mixing pump or high pressure mud tank. The clean water would be pumped into the water line with sufficient power. GN’s design on the mud gun line and clean water save cost on additional pipeline and effectively use the mud tank existing structure.

A complete drilling mud recycling system always includes 2 parts, the mud recovery and cleaning system part, the other part is mud mixing system. Just as the name implies, the mud mixing system is functioned to mix the chemicals with the mud base and make it usable for the rig drilling.

GN Mud Mixing Unit

GN Mud Mixing Unit

How many pipeline channels needed for mud mixing

As we know, the processing of mud mixing is consisting of mud suction from every mud tank compartment in the system and again pumping the mud back. There we will know we need design 1 mud suction line and 1 mud mixing line. Both of these 2 pipelines would be laid to each compartment for mud storage. Under the centrifugal force of the mixing pump, the mud would be sucked to the mud mixer unit; here the mud chemicals would be added into the mud and get to the mud tank for fully mixing with the flow of mud through the mud mixing pipeline. In order to produce the sufficient pressure for driving the mud, the inlet of the pump is larger than outlet. Accordingly, the mud suction line diameter is bigger than the mixing pipeline.

What is the location of the mud mixing pipeline inside the tank

Due to different functions of the mud suction line and mixing line, the location of the 2 pipelines are different either. For the suction line, to make sure it would be maximally suck the mud inside the tank, it always is designed to locate at the bottom of the mud tank. Thus, even very low liquid level; the pump could suck the mud for mixing. The mud mixing pipeline is connecting with the centrifugal pump outlet with extended steel pipeline which would be located on upper part of inside tank. The mud gets out from the mixing pipeline with high pressure and when dropping down, it would also stirs the existing mud for mixing, here the mud agitator would definitely is the main equipment for mud agitating.

As per the request capacity of the mud storage, the quantities of the mud tank would be different; we need design the connection parts among these tanks for the mud suction and mixing line to make all the tanks a communicating vessels so that the pump could suck from and delivery to each mud tank.

GNLW223 Series decanter centrifuge is a main product of GN Solids Control, different from the centrifuge used in oil drilling and drilling cuttings management system. The GNLW223 centrifuge is more compact structure and has a relative small treating capacity which determines this series decanter centrifuge is always be used in diamond drilling mud recycling.

GNLW223 Decanter Centrifuge

GNLW223 Diamond Drilling Decanter Centrifuge

GN now could provide this GNLW223 centrifuge electric drive fixed speed GNLW223G and Variable Speed GNLW223-VFD.
Both of the two models are driven by one unit electric motor. Regarding the motor and control panel, GN could also provide IEC explosion proof standard which could be used in hazardous area. Some customer may prefer the fully hydraulic drive model, at this time, GN hydraulic driven centrifuge for GNLW223 still under research process. But GN could provide the Decanter Centrifuge without motor and control panel, the customer could get the hydraulic driven unit locally and assembly together with the mechanical part. The unit which was sent to Canada is like that.
GNLW223 series decanter centrifuge has a normal treating capacity of 6 cubic meters per hour. The designed maximum rotating speed is 4900RPM. If variable frequency drive, the speed would be 0~3800RPM. Under general condition, the solid particles size in diamond drilling is very fine, however, sometimes, there would be large size drilling cuttings. Thus, one unit shale shaker maybe needed as first stage cleaning equipment to remove the large size solid particles. GN has a mini model shale shaker GNZS752 is especially for this job.
The mud system for diamond drilling is very simple; always it is consisting of mini shale shaker, GNLW223 decanter centrifuge, and mud tank and mud agitators.
Diamond drilling is very popular in Canada, there are more than 50 diamond drilling company in Canada right now. GNLW223 series decanter centrifuge has already been used in Canada for diamond drilling and performance proved very good.

Specifications for 750hp workover rig mud system package

Complete Mud system package for 750hp workover rig including but not limited to the following:

3 Mud Tanks, volume of each 40 cubic meters, for 750hp workover rig mud system package.

oil rig mud system

oil rig mud system

Mud Tanks Specifications of the 750hp workover rig mud system package

API Skid I Beam, API lifting.

Bottom tanks steel sheet 12 mm thickness

Side Walls of corrugated steel 40 mm thickness

Suction Line in bottom 8” x 6” Schedule 80

Drain line with 10” butterfly valve

Top ream of 4” pipe schedule 40

Equipped with all required butterfly valves

Tanks to be covered with API Grating & with API Hand Rails

750hp mud system package Mixing tank of 2 compartments equipped with the following

6” Mud Hopper

2 Mud guns

2 Mud Agitators

Two Mission Type centrifugal Pumps (8×6-14) 75 HP

Active Tank for the 750hp workover rig mud system of 2 compartments equipped with the following

2 Mud guns

2 Agitators


Shale Shaker Tank for the 750hp workover rig mud system equipped with following

Two Shale Shakers rated capacity up to 600 GPM, and sand trap.