Spent WBM Dewatering system is used to treat the spent WBM in the drilling mud pit. After completion of drilling operation, the spent water-based mud in the mud pit needs to be treated according to environmental protection requirement. Normally, we have two options to deal with the spent WBM- by centrifuge and polymer unit or by filter press and polymer unit. Here in this chapter, we will give a general comparison between centrifuge treatment and filter press treatment, the advantages and disadvantages of each solution.
1) Spent WBM dewatering by Polymer unit + Centrifuge
| S/N | Product | Short Description |
| 1 | 3-chamber automatic dosing unit | Used to mixing and aging of Polymers to coagulate the fine solids in the WBM, normally we can use PAC or PAM agent |
| 2 | Pipeline with static mixer | The pipeline will link the dosing unit with decanter centrifuge, the aging polymer and waste WBM will be mixed fully in the static mixer, and then feeding to decanter centrifuge |
| 3 | Centrifuge Feed Pump | Normally we adopt progressive cavity pump as feeding pump to centrifuge. The spent WBM will be transferred to the static mixer continuously by feed pump, the feeding will be without pulse, stable feeding |
| 4 | Decanter Centrifuge | The spent WBM after mixed with polymer will be separated by high-speed decanter centrifuge, it is easy to get clean water from centrifuge; the mud cake moisture normally can be about 40%~50% |
| 5 | Mud skip or tanks | Mud Skips or tanks may be required to collect the dry mud discharged from centrifuge |
| 6 | Water Tanks | Water tanks may be required to collect the clean water discharged from centrifuge. |
The composition parts of centrifuge dewatering unit as above table, Features of Centrifuge dewatering unit as below:
2) Spent WBM dewatering by Polymer unit + Filter Press
| S/N | Product | Working Description | |
| 1 | Submersible slurry pump | used to transfer the spent WBM from mud pit to our system | |
| 2 | Dosing and mixing tank system | used for flocculation and mixing with spent WBM | |
| 3 | Dosing unit | 2 or 3 sets dosing unit for PAC or PAM flocculation | |
| 4 | Cleaning water collection tank | Cleaning water collection tank; also working to supply water to the dosing tank system | |
| 5 | Plate and frame filter press | to final treatment the spent WBM after coagulation and flocculation; The user can get dry mud cake and clean water | |
| 6 | Remarks | We can suggest on the specific workflow and dosing ratio per request | . |
The composition parts of filter press unit as above table, Features of filter press with polymer unit as below:
