Oil Production and Recycling
Flowback, Produced Water treatment systems are designed to precipitate and remove TSS (Total Suspended Solids), Emulsified Oil and Dissolved Metals (such as Iron). Additionally, these systems can adjust pH and disinfect water. These steps allow for a quick re-deployment / re-use of the water in production.
Design Considerations
Water is one of the most expensive yet reusable part of oil production and recovery. The ability to re-use and recycle water in a cost effective manner can be a competitive advantage for our clients. HydroFloTech mobile and modular systems are pre-plumbed, pre-wired and are very quick to deploy with most systems take less than 1 day to install and start-up. HydroFloTech systems currently operating in the Permian Basin are fully mobile, fully automated and require minimum operator involvement. Most clients are able to remotely monitor and track production, chemical use and other key performance indicators (KPI) not just on site but also back at headquarters.
HydroFloTech has designed a fully modular system for treating and possibly recycling wastewater from produced water and oil recovery:
Pre-Treatment Module: This module removes large solids and equalizes the water prior to any further treatment. The goal of this module to get the water provide the downstream treatment equipment with an equalized stream of water which if free from large solids.
Side Hill Screen / Grit Removal System: “Side hill” or “Grit Removal Systems” are used for the removal of large insoluble material from wastewater flows. These screens or systems are used on process and wastewater streams for particles that need to be removed to protect downstream systems. These screens can also be used for product recovery; large solids separation and mixed settleable solids for both municipal and industrial applications.
The HydroFloTech Side Hill Screen or Grit Removal System maximize solids removal in an easy to maintain unit. The screen is a barrier by which material larger than the gap or slot size may not pass, allowing the water to continue through.
Equalization Tank: HydroFloTech can work with an existing equalization “EQ” tank or provide one. Materials of construction can includes: Fiberglass (FRP), HDPE, steel (carbon steel or stainless steel), concrete, or even in-ground storage pits / ponds / lagoons. The purpose of the equalization tank is to “equalize” and narrow any variances in water characteristics. The EQ tank also acts as a great buffer for two main purposes: First the EQ tank provides a buffer storage capacity in situations when there is a temporary surge in flowrate. This allows the system to be smaller than the peak surge flowrate. Secondly, the EQ tank also provides the ability to “narrow” any spikes in any contaminants.
Oils and Solid Removal System
When the wastewater has oils and other contaminants that needs to be treated, the following process may be utilized:
Chemical Pre-Treatment and Solid Removal: This module chemically treats the water with pH adjustment (as necessary), coagulant and polymers to enhance the ability of HydroFloTech inclined plate clarifiers or dissolved air floatation systems (DAF) to effectively remove any Total Suspended Solids (TSS) or Fats, Oils and Grease (FOG).
ChemiSep Chemical Pre-Treatment System: The efficacy of any wastewater is as good as the pre-treatment of the wastewater prior to removal of any impurities. The HydroFloTech ChemiSep Pre-Treatment System provides great flexibility in treating various wastewater profiles:
- Stage 1 – Emulsion Cracking / Acidulation / “Acid Cracking”: pH is lowered to ~3.5 with the pH controller using acid to break any emulsion.
- Stage 2 – Precipitation & Coagulation: pH is raised to 8.5 with the pH controller using caustic while adding a coagulant such as alum or a PAC. A “pin floc” is developed indicating the emulsion and the suspended solids are precipitated.
- Stage 3 – Flash Mix: The wastewater with it’s precipitated pin floc is introduced to the flash mix zone where a polymer flocculent is added. This stage maximizes flocculent dispersion throughout the coagulated wastewater.
- Stage 4 – Flocculation: The wastewater is now introduced to the slow mix zone to agglomerate the floc into larger particles suitable to be enmeshed with the air bubbles.
ClariDAF (Clarifier + DAF Combination) System: The flocculated wastewater is introduced into the ClariDAF Clarifier + DAF Combination System inlet where the particles are comingled with a pressurized dissolved fine bubble recycle stream. The suspended floc particles attach to the bubbles and float to the surface where they are mechanically skimmed into the float scum sludge chamber. The heavier floc particles sink to the bottom through the inclined plates and they are captured in the hopper bottom. The clarified treated water then exits the end of the ClariDAF and flows downstream to further treatment as necessary. The settled and skimmed solids are further processed through the sludge management system.
Sludge Management System: This module removes the precipitated solids from the water and converts those solids into dewatered “sludge” which may be eligible for re-use or landfill disposal.
Sludge Tank with Sludge Transfer Pump: The accumulated sludge is periodically removed from the clarifier and sent to a sludge holding tank where it further thickens for disposal or dewatering.
Sludge Dewatering: Sludge dewatering is typically handled by a HydroPress Filter Press or Screw Press. After processing a batch of “sludge” the filter press or screw press is emptied of “chrome cake” which is a semi solid of approximately 20-35 % solids. Chrome cake is high in chrome and sulfite and should be disposed of according to environmental regulations.
Re-Use Module: This module further reduces any remaining solids and biological / bacterial growth in the water to make it suitable for re-cycling or re-use.
RO System: The RO System removed any remaining dissolved solid (TDS) in the wastewater. The effluent coming out of the RO System is suitable for re-cycling / re-use.
UV Filter System: The UV Filter System finishing a final sanitizing of the water. The UV Filter System allows for the treated water to be used for most re-use / recycling purposes.