RIASSUNTO
Abstract
Fresh water scarcity and increasing demand are worldwide concerns and arebeing addressed by a number of water man-agement initiatives in Alberta andCanada.In 2003, 0.3 bil-lion m3 of produced water was injected intodisposal wells associated with oil and gas production in Alberta.Thisvol-ume of water is a potential resource for recycling and benefi-cial reuse inAlberta, which would have a significant impact on sustainable development inAlberta. This water must first be treated to meet water qualityrequirements and regulatory guidelines for specific applications.Thispaper provides a comprehensive technical and economic review of watertreat-ment technologies and shows that water treatment processes arecommercially available.Although the cost of implement-ing suitabletreating processes to meet drinking water quality guideline is estimated atthree times the current cost of mu-nicipal water supply in Alberta, it is morefeasible to recycle produced water for other purposes, such as agricultural orpe-troleum application (i.e., waterflooding, etc.).This is because waterquality guidelines for most other applications are not as stringent as that fordrinking water and there is increasing pub-lic resistance for industry to usefresh water for commercial applications. A multi-disciplinary researchand development team studying water recycle and beneficial reuse is necessaryto look into these issues. The University of Calgary is set tocollaborate on such projects due to the current research em-phasis onsustainable energy and environmental impact. Col-laboration between thegovernment, industry and academia to develop initiatives aimed at reducingfresh water is possible in Calgary for several reasons.One is theproximity of many major oil and gas companies in this city, which would allowfor easy communication.Another is the fact that the current price of oilwould not inhibit producing companies from in-vesting in this kind ofresearch.The result can be well-developed initiatives to treat andrecycle produced water for beneficial reuse, thus reducing fresh water demandfor many applications in the petroleum and agricultural industries.
Introduction
Fresh water is a limited resource as only one percent of all the water inthe world is available for worldwide demand.Even Canada, which has thelargest per capita water supply in the world, experiences watershortages.This water is needed for agricultural,industrial/commercial/institutional (ICI) and do-mesticapplications.Domestic water use actually constitutes the least of allmajor water users[1].On the other hand, the need for fresh water inwaterflood operations and steam generations in enhanced oil recovery projectsare major concerns in Al-berta.These issues, along with the need forsustainable pro-ject development and increasing public resistance towards usingfresh water for industrial applications, increase the awareness for industrialwastewater treatment and reuse.Treating produced water for reuse is aviable alternative to withdrawing fresh water from surface and ground watersources.
This paper reviews both commonly used and novel water desalinationtechnologies, identifies major challenges in produced water recycle andbeneficial reuse based on applicable water quality guidelines and points outpotential research and development activities in this area.The purpose isto show that water treatment isn't as prohibitively expensive as commonlybelieved and point out areas where further research and development can makewater reuse a sustainable activity.
Figure 1 shows the breakdown of fresh water allocation in Alberta during2003[2].This figure shows that out of the 9.7 billion m3 of fresh waterallocation, 4.5 billion m3 was allocated for irrigation and approximately 0.5billion m3 was allocated to the petroleum industry.By comparison to thevolume allocted to the petroleum industry, there was almost 0.6 billion m3 ofproduced water in Alberta during 2003[3].Approximately half of thisvolume was injected for reservoir pressure maintenance and waterflood. Almost0.3 billion m3 of produced water were injected into deep disposalwells[4].A relatively small volume of produced water, 5.6 millionm3was recycled as steam in steam recovery projects.