Treating SAGD Blowdown With the SaltMaker MultiEffect Evaporator Crystallizer

May 4th 2023

Steam assisted gravity drainage (SAGD) blowdown water from three operating sites was treated using Saltworks’ SaltMaker MultiEffect Evaporator Crystallizer. The energy-efficient treatment system reduces the cost of blowdown transport and disposal. MultiEffect produces a low-volume solid that can be disposed of at a Class II landfill and recovers freshwater for reuse.

Photo of a SaltMaker evaporator crystallizer used in SAGD applications
SaltMaker MultiEffect evaporator crystallizer test pilot

SAGD and Blowdown Water Management Issues

SAGD is an enhanced oil recovery process that uses injected steam to reduce bitumen viscosity and increase oil production. This process generates produced water alongside oil production and recycles the water as much as possible before ‘blowdown’ is required. Blowdown purges dissolved solids and organics from the SAGD water balance so they do not accumulate to a detrimental level in the recovery process. The majority of SAGD operators dispose their blowdown waters in deep wells and withdraw fresh or slightly saline water to make up the loss. Increasingly, operators truck their blowdown water to deep wells, resulting in high operating costs and associated environmental impacts. 


Blowdown management can be the second largest cost of production, after natural gas usage to generate steam. As a result, operators are seeking onsite solutions for treating blowdown water to remove freshwater from the blowdown for re-use, and condense all waste to solids for safer and lower cost disposal in certified landfills. Conventional crystallizer systems have been trialed with limited success due to plugging from the highly saturated mixed ionic-organic chemistry, high energy demands, and the requirement for a gas fired drier to complete the final solids production. 

Dealing With SAGD Blowdown: SaltMaker MultiEffect Evaporator Crystallizer

Saltworks’ SaltMaker MultiEffect was proven to reliably treat SAGD blowdown to recover freshwater for reuse and produce solids suitable for disposal in Class II (non-hazardous) landfills. Both Once Through Steam Generator (OTSG) and evaporator blowdown were successfully trialed with four active SAGD operators.


SaltMaker MultiEffect is a low-temperature crystallizer (<90°C) that was designed from the ground up to treat and produce solids from the toughest waters. The zero liquid discharge system uses low-grade waste heat in multiple effects to reduce energy consumption and operating costs. Since there is no steam in the process, steam ticketed operators and time-consuming certifications are not required during installation and maintenance.


The SaltMaker MultiEffect uses humidification-dehumidification (HDH) principles for low-temperature operation and provides three fundamental design benefits at the expense of footprint: (1) process components are built from engineered plastics that remove concerns for corrosion and scaling/fouling; (2) high circulation rates provide a scouring effect on highly saturated flows; and (3) sensible heat transfer occurs in place of boiling, which removes troublesome tube scaling.


Also, full automation and intelligent cleaning operations built into the SaltMaker MultiEffect measure scaling potential and initiate automated cleaning cycles prior to irreversible scaling. The modular design is based on ISO shipping container blocks for low-cost and rapid dispatch, installation, and expansion. Modules can be slid in and out for simple inspection without confined spaces. A standard S125 SaltMaker MultiEffect has a capacity to remove 125 m3/day of water. Higher capacities are achieved by adding more S125 plant blocks.

Photo of raw blowdown (left) and condensed water (right) from a SaltMaker MultiEffect
SaltMaker MultiEffect condensed water (left) and raw blowdown (right).

Results of Four SAGD Evaporator Blowdown Treatment Pilots

Three different sources of SAGD evaporator blowdown were tested, alongside one source of OTSG blowdown. The testing included a 60-day onsite pilot test at a SAGD facility in Fort McMurray in the middle of winter. All SaltMaker MultiEffect pilot tests operated reliably, 24/7.


Saltworks’ patented non-scaling design and self-cleaning systems were paramount to operations. In addition, when coupled with the SaltMaker MultiEffect’s patented system for low-temperature solids production and extraction, the plant solved a major SAGD problem: continuous solidification and extraction of both ionic and organic components that prevents accumulation and results in gelling or plugging of conventional systems.

Chart showing SaltMaker MultiEffect recycling of 80°C heat
SaltMaker MultiEffect Recycling of 80°C Heat
Chart showing solids production over time by the SaltMaker MultiEffect evaporator crystallizer
SaltMaker Brine: Reliably Reaching Saturation

The project results are as follows:

  • High quality freshwater recovered (<500 mg/L TDS).
  • Continuous, reliable production and extraction of solids. Analytical tests demonstrated that solids met applicable requirements (e.g., paint filter test, leachable metals, BTEX, pH, and flashpoint) for disposal at a non-hazardous Class II landfill.
  • Reliable operation and non-scaling/no-plugging with automated self-cleaning, confirmed by complete plant autopsies after each trail.
  • Recycling of the heat through multiple effects for energy efficiency.

Photo of solids from a zero liquid discharge treatment chain with a SaltMaker MultiEffect evaporator crystallizer
SaltMaker MultiEffect solids suitable for Class II landfill disposal
A table of data from the treatment of raw evaporator blowdown using the SaltMaker MultiEffect evaporator crystallizer
Data from treating raw evaporator blowdown using the SaltMaker MultiEffect evaporator crystallizer

The pilot projects demonstrated that the SaltMaker MultiEffect reliably and efficiently recovers freshwater and produces solids from SAGD blowdown waters. Saltworks can complete a SaltMaker performance and economic assessment of your blowdown water treatment project. Contact us today to get started on your project.

About Saltworks

Saltworks Technologies is a leader in the development and delivery of solutions for industrial wastewater treatment and lithium refining. By working with customers to understand their unique challenges and focusing on continuous innovation, Saltworks’ solutions provide best-in-class performance and reliability. From its headquarters in Richmond, BC, Canada, Saltworks’ team designs, builds, and operates full-scale plants, and offers comprehensive onsite and offsite testing services with its fleet of mobile pilots.

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