Currently there is no facility in place to pilot and commercialize the next generation of technologies for produced water treatment in Steam Assisted Gravity Drainage (SAGD) for bitumen extraction from oil sands. A recent feasibility study indicates strong stakeholder support for such a facility in Northern Alberta, and provides some recommendations on implementation.

Steam drive bitumen production processes such as SAGD consume large quantities of steam and consequently generate significant amounts of produced water, which must be treated to a quality acceptable for use in a once-through steam generator. The trend to reduce makeup water consumption is being strongly encouraged by regulatory bodies, in order to achieve as much recycle of water as possible and minimize the need for make-up water.

A feasibility study was sponsored by the Petroleum Technology Alliance Canada (PTAC) Water Innovation Planning Committee (WIPC), with Alberta Energy Research Institute (AERI). The study goals were to establish the need for a SAGD water treatment test facility, to determine who would need such a facility, what will be done at the facility, where the facility should be located, how the facility will be utilized, and who should own and operate the facility.

A diverse number of stakeholders were surveyed, including SAGD operators; water treatment equipment suppliers; engineering firms; government regulatory agencies; and academic institutions.

Sixty-four percent (64%) of respondents responded affirmatively when asked explicitly if there was a need for such a facility. Sixteen percent (16%) responded “maybe”. Therefore, sufficient support for the facility was established.

The stakeholders identified key benefits they wish to derive from use of the facility:

• Reduce fresh water use; investigate use of saline sources.
• Increase recycle.
• Reduce overall operating costs.
• Reduce system energy requirements.

Based on survey results, the Steering Committee determined that the test facility must have the flexibility to treat water from a variety of water qualities, e.g. make-up water, produced water, recycle water, to a variety of water qualities, e.g. once through steam generator, drum boiler feed quality. The survey respondents identified de-oiling technologies as their primary testing objective, with 28% of respondents prioritizing this. Next, at 24% were softening and polishing technologies.

The Steering Committee determined that the project should culminate in the preparation of an EOI, which will be distributed at a later date by PTAC, in order to engage parties interested in the ownership of the test facility.

Based on the key design and functionality criteria determined by the Steering Committee, the representative facility concept is comprised of several mobile, trailer-mounted modules to which vendor-supplied pilot units would be connected. The modules, as described in the EOI, are organized by treatment goal, and contain permanent infrastructure within the unit to support the connection of various pilot units externally. The permanent infrastructure includes pumps and tanks necessary to deliver the appropriate feed water and collect the waste water, as well as instrumentation, chemical feeders, and permanent vessels, for example, appropriate for testing various media or ion exchange resins.

The feasibility study, with full survey results indicating water trends among SAGD operators, as well as the representative facility concept, is available here (PDF).

Source: Petroleum Technology Alliance Canada.