Drilling Mud Recycling System

3 phase decanter centrifuge is the common used equipment for oil sludge separation unit and oily water separation project, based on client’s different requirement for the treatment result, we will select proper equipments, 3 phase decanter centrifuge or 2 phase decanter centrifuge plus 3 phase disc centrifuge. They have their own advantages and disadvantages.

3 phase decanter centrifuge is a solids, liquid, liquid 3 phase separation machine, the 2 phase liquids should have specifically different density, and the solids phase should be specifically heaviest phase, which can be easily separated. The separation principal is sedimentation, when the oil sludge is feed to the centrifuge inlet pipe and enter into high speed bowl, the material rotates synchronously with the bowl. When gravity is different, the generated centrifugal force is also different, the solid phase ( the heaviest phase) with largest gravity, then water phase with 2nd largest gravity , the oil phase with the lightest phase and smallest gravity. The solids phase is in the outtest layer of the screw, the oil inside, the centrifugal force became less from outside to inside. The solids are pushed by the screw conveyor, the water which is heavier is discharged from the nozzle in the upper position of the big end, the oil which is the lightest phase will be discharged from the bottom nozzle of the bid end. The solids, oil, water discharged from 3 phase centrifuge is not with high quality, if your requirement is very concerned about the oil quality for recovery , water quality to be sent to waste water treatment facility, solids quality for disposal, it can not meet your requirement.

Another solution is to use 2 phase decanter centrifuge plus 3 phase disc centrifuge, it separated the working process as solids liquid separation firstly, then liquid liquid separation, with proper chemicals adding and heating, the treatment result can reach expected target.

This week GN solids control shipped one batch of waste sludge dewatering equipments to Environmental company, including: Dewatering Centrifuge, Screw Press Dewatering Machine, and Chemical Dosing Unit.

The dewatering centrifuge package including one unit of dewatering centrifuge, 1 set of mud tank to collect the clean fluids, one unit of submersible slurry pump as centrifuge feeding pump, 1 unit of mud agitator for agitating the slurry. The chemical doing unit will feed the prepared chemicals to the dewatering centrifuge and well mixed in the centrifuge feed tube, then the mixture chemicals and slurry will be enter into the dewatering centrifuge, under the working of G force, the light fluids are discharged from fluids discharge port, the solids are discharged from solids discharge port, both of the fluids distribution port and solids discharge port are protected by tungsten carbide alloy, and it is interchangeable once damaged.

The Screw Press Dewatering Machine is a sludge extrusion dewatering equipment. The working principal is by the strong squeezing force generated by the change of screw diameter and screw pitch, and the tiny gap between the floating ring and the fixed ring, to realize solid-liquid separation. It can be widely used for dewatering the industrial waste sludge, oil waste sludge and other sewage treatment projects. It can work continuously and automatically, it will not block frequently. It is energy saving and environmental friendly solution, compact design with small footprint, only need a small space to locate it. Just compared with dewatering centrifuge, its treating capacity is not so high. Especially for oil sludge treatment, decanter centrifuge treatment result is the best. But screw press is with lower energy consumption and a little lower cost. Compared with screw press and decanter centrifuge, filter press investment is very high, and efficiency is lower, discharged solids is drier.

Recently GN produced HDD mud reclaimer for international drilling company are ready for shipment, including 2 sets of GNMS-500D desander unit, 1 set of mud mixing tank, 1 set of dual deck shale shaker. The technical configuration is as below:

2 sets of GNMS-500D desander unit: this model is the widely used for HDD mud recycling, TBM slurry desanding, piling slurry cleaning works. It is a compact design mud cleaning unit, which can be used when treatment result of solids separation cut point 45 microns is acceptable, and space is very limited, and budgetary is limit, the user do not need a desilter cone treatment ( the solids cut point is 20 microns) or they can prepare for an extra desilter or decanter centrifuge as further treatment. Normally when GNMS-500D desander unit is applied, the user will make a storage tank or mixing tank with mixing hopper and mixing pump locally, the clean fluids discharged from the desander unit will flow to the mixing tank directly, it will be used to prepare for new drilling fluids for reuse purpose. The desander unit including a double deck shale shaker with hydrocyclones, centrifugal pump, catching tank, electric control system with pipelins, tank accessories.

The mixing tank is customized design , which consist of 2 venturi hopper with 2 mixing pump installed on the skid.
The double deck shale shaker working principal is as below:
A slurry pump pick up the HDD slurry from mud pit to the feed port and flow to the buffer tank, the coarse solids will be separated by the top layer shaker screen, the fluids drop down on the bottom screen for drying and collect more useful fluids. The clean fluids will drop down into the mud tank and the solids are separated out.

If you need HDD mud reclaimer, pls contact with GN solids control.

Recently one unit of oil based drilling cuttings treatment system are shipped to China ES company. The system including one unit of GNCD930F vertical cuttings dryer, one unit of GNLW363C-VFD decanter centrifuge, with skid and screw conveyor, etc. components.

This drilling cuttings treatment system is mostly applied for oil based drilling cuttings treatment, for water based drilling cuttings, we will suggest different system to treat, like high G drying shaker, decanter centrifuge with dewatering unit. When the vertical cuttings dryer is used to treat water based drilling cuttings, the screen basket is easily blocked, you have to flush it very frequently, the treated solids will be with more moisture, which will influence the treatment result.
The screw conveyor is used to transfer the drilling cuttings from solids control system / waste pit to vertical cuttings dryer. Sometimes we will use the excavator to dump the waste into a big collection hopper, which will drop down into the obliquely installed screw conveyor directly, the screw conveyor will transfer the drilling cuttings to vertical cuttings dryer feed port on the top of the machine. Another feeding method is that when the drilling cuttings treatment system is installed on the rig site, besides the solids control system, one screw conveyor which is horizontally installed will collect the drilling cuttings from primary shaker, mud cleaner, the cuttings are discharged to another obliquely installed screw conveyor through the discharge port, the cuttings are feed to vertical cuttings dryer by the #2 screw conveyor.

The cuttings are feed into the feed port of the vertical cuttings dryer, the screen basket trap the wet solids and accelerate the speed to 900rpm ( the user can input the speed from the control panel) and G force is up to 420G, the liquid passed through the screen opening, the solids are extracted by the rotor flights, the rotor assy rotate slower than bowl, the solids are discharged from discharge port.

Recently one set of drilling mud treatment equipments are sent to overseas engineering service company, including GNMS-500D Desander Unit and GNLW224ET-VFD Decanter Centrifuge Unit.
The technical configuration is as below:

1. One unit of GNMS-500D Desander Unit, which can be widely used as mud cleaning unit for HDD, Bored piling, TBM slurry treatment. The designed treating capacity is 500gpm, the features of this desander unit is as below:
   1) Compact design, small footprint
   2) Competitive price for economic solution of mud cleaning
   3) Only for mud cleaning, without mud mixing and mud storage, the user can connect it with further jet mud mixer unit with their own storage tank
   4) Easy operation and maintenance, including 1 unit of double deck shale shaker with one unit of desander cone, the bottom layer shaker screen as coarse solids separation shaker, the top layer screen as fine solids separation screen, to dry the discharged solids separated from desander cone. One unit of centrifugal pump as feeding pump, one catch tank to collect the fluids discharged from coarse solids separation shaker screens temporarily, one control panel to control all the motors in the unit. After treatment by GNMS-500D desander unit, the separation cut point is 45 microns. If the user want to separate more fine solids, they can use a desilter or use a decanter centrifuge.
2. GNLW224ET-VFD Decanter Centrifuge Unit, including a decanter centrifuge with a fluids catching tank. The features of this unit is as below.
   1) Compact design
   2) Separation cut point 2~5 microns
   3) T series decanter centrifuge is special designed dewatering centrifuge to separate ultra fine solids from fluids, after treatment, the water can be reused to prepare for new drilling mud or send to waste water treatment for final disposal. With chemical dosing unit, the working efficiency can be highly increased.