# Experimental Study of High-Pressure Oxy-Fired Direct Contact Steam Generation (HiPrOx-DCSG) with Steam-Assisted Gravity Drainage (SAGD) Produced Water

## TL;DR

This study tests a high-pressure steam generation system using contaminated water from oil extraction, showing it can produce steam suitable for reuse in the process.

## Contribution

The study demonstrates the feasibility of high-pressure oxy-fired DCSG for steam generation using SAGD produced water.

## Key findings

- The system generated pressurized steam-rich gas with about 90% steam and CO2, suitable for CO2 coinjection into SAGD wells.
- Oxy-fired combustion effectively removed impurities from the SAGD water.
- Burner surface deposition was reduced at lower pressures (55 and 30 barg) compared to 80 barg.

## Abstract

Direct contact steam generation (DCSG) produces steam-rich
gas
by directly contacting combustion gases with sprayed water. This water
is typically produced water (i.e., recovered condensate) from a process
that has already extracted heat from the steam-rich gas. DCSG enables
the reuse of produced water for steam generation without the extensive
treatment required by conventional boiler systems, making it suitable
for applications where a high steam purity is not essential. Key challenges
in DCSG include managing impurities during combustion and matching
the flue gas pressure with the elevated downstream process pressure,
often necessitating pressurized combustion. This requirement becomes
advantageous when integrated with carbon capture and storage (CCS),
especially with oxy-fired combustion where flue gas, following H2O condensation, yields a pressurized CO2-rich stream
requiring less energy for downstream capture and compression. This
study tested a pilot-scale high-pressure oxy-fired (HiPrOx) DCSG system
operating at pressures of 80, 55, and 30 barg and temperatures between
1000 and 1250 °C, using steam-assisted gravity drainage (SAGD)
produced water. The system successfully generated a pressurized steam-rich
gas containing approximately 90% steam, balanced by CO2 and trace gases, suitable for CO2 coinjection into SAGD
wells. Oxy-fired combustion effectively removed solids and impurities
from the SAGD water; however, burner surface deposition was severe
at 80 barg. Deposition was significantly reduced and acceptable at
55 barg and minimal at 30 barg. The results demonstrate the feasibility
of HiPrOx-DCSG for utilizing highly contaminated water for steam
generation.