Tag: pitless-drilling-mud-processing

Dewatering system for oil base mud waste

on 02 December 2021  Solids control equipment  dewatering system, dewatering unit, drilling waste management, pitless drilling mud processing

A dewatering system here is a complete unit to process drilling mud waste. Drilling mud waste including the solids discharge from solids control equipment or system or the sediment material in mud tank. We need special equipment to process such materials for environment conservation.

Dewatering system infromation

For such system, there are usually filtration, separation, drying equipment. In practice, oil base mud waste and water base mud waste requests different procedures and equipment. But the processing step are same in general.

The equipment including drying shaker, cuttings dryer, oil separator, decanter centrifuge, transfer pump, auger feeder, tanks or pits, flocculant unit, coagulant unit, control panel and so on.

Procedure of the processing

Oil base mud waste is transferred to a drying shaker by a sludge pump for further filtration. The discharged cuttings/solids will be transferred to vertical cuttings dryer (optional) by screw conveyor (optional) together with tails from all previous equipment discharge.

If we don't use cuttings dryer, the sludge or waste will be pumped to oil separator directly, if we use the cuttings dryer, the material discharged from dryer, and sludge/waste introduce to the oil separator. Then centrifugal pump transfer fluids to wast collection tank, while oil is collected to the oil tank.

Further centrifugal pump transfer waste fluids to dewatering unit. Including the coagulation and flocculation tank. The screw pump transfer liquids to decanter centrifuge, the discharges from centrifuge will be collected and pressed by filterpress in filtration unit including ultra purification device. Finally, the clean water is transferred to water tank for reuse.

Dewatering system procedure

Dewatering system procedure

Dewatering unit specification/features

Automatic chemical dosing unit with 1000L capacity for coagulation with dosing pump. S.S316  tank for polymer mixer and storage set with HMI PLC control panel. Furthermore, there is high sensitive safety breaker on the automatic main control panel. A 5000L water tank for solution fit 1 set dosing pump. Flocculation sample hole and valve available. All pipelines and valves are anti-corrosion and deposit-free. Safety equipment including eye wash, fire extinguishing, full face anti-dust mask and complete set safety marks

This unit can recover 60~85% of aqueous phases from the waste. And 40% reduction of waste volume. The liquid phase contained in the waste is almost totally recovered and recycled in tank for new drilling fluid mixing or further drilling activities. So, it dramatically reduces the cost of transportation for the fluids or water needed for operation. Of course, the produced water is tested for different ions.

We know in a dewatering system, there are both coagulation and flocculation device. The flocculation is achieved by chemicals. It's the most common way to remove dissolved particles in solutions. The ions are converted to an insoluble. Particles formed by this reaction are removed from solution by settling, filtration or other separation equipment. In the flocculation phase, there are mixing, chemical dosing and control panel modules.

Sludge separation unit specification

It including a set of 60 plate filter press, a 5000l ultra-filtration unit, a bacteria control dosing unit and PH control dosing unit. Such components are contained in 40' container for convenient transfer and handling. All necessary components and modules are fit well similar to the coagulation unit.

For sludget separation part there is mechanical separation procedure. It can provide optimized solution for drilling waste management. Centrifuge configuration in such unit is very efficient and cost-effective.

And for filter press, it suits for almost all types of sludge. The inorganic conditioning is often recommended to enable satisfied cake released due to minimal adherence to filter cloth. The Filter press generally requires the addition of lime only. Hydrophobic inorganic sludge is very dense and ideal for the filter press. It is dewatered without any preliminary conditioning. For oily sludge, the filter press can be used to treat sludge containing light oil, the presence of grease can sometimes impair the smooth running of the filter; clothes have to be degreased at frequent intervals.

According to different amount of material to filter and press area, we can select different model of filter press. Such as filter press holding filtration area 100m2, the flow rate is 30-50m3/h, etc. Of course, to let filter press and whole system work well, we need proper pumps, too.

In the whole dewatering system, the decanter centrifuge is optional. But we suggest using it. It removes fine solids from solids and liquid misture. The VFD driven configuration is very popular with users operating dewatering system.

Do you have any interest or more questions? Let us know freely, trust Aipu will give you the optimal solutions at a very competitive cost