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The historical, current and future international practice of cumulative effects assessment and management (CEAM) is addressed. The 'context' of CEAM is explained and challenges from scientific and policy issues and numerous uncertainties are described. A six-step generic process for carrying out CEAM is provided. Opportunities for mitigation and management are highlighted, with emphasis given to 'collaboration' as a foundational element for dealing with cumulative effects. This state-of-practice review concludes by noting six 'ugly lessons' which result from lack of appropriate attention, eight 'bad lessons' which reflect practices that need improvement, and 12 'good lessons' which can be used to articulate good practice principles related to CEAM. In many situations some modification of EIA methods and tools may be necessary. In summary, the practice of CEAM is growing out of its infancy. As experience is accrued, it is anticipated that good practice principles will be further articulated and utilized on an international basis.Keywords: EIA, CEAM, methods and tools, mitigation, management, best practices HE GOAL OF THIS REVIEW is to concisely summarize the state of the professional practice of cumulative effects assessment and management (CEAM). Both authors have experience related to university-level teaching about environmental impact assessment (EIA) and CEAM, and in conducting related sponsored research and advising graduate students in their research. They also have independently and collaboratively taught professional-level CEAM short courses for government agencies and the private sector. Further, they both have consulted on the planning and conduct of CEAM studies, and have prepared relevant sections or chapters in subsequent environmental impact statements (EISs) or environmental assessments (EAs). Finally, they both have reviewed impact study documents and provided suggestions for improvement. The second author has also served on several EIA review panels for the Canadian government. As a result, both authors have planned, reviewed and conducted comparative evaluations of the CEAM features within prepared compliance documents, or as separate study documents (Baxter et al, 2001;Ross, 1998;Cooper and Canter, 1997). Such reviews with similar findings have also been conducted in the UK (Cooper and Sheate, 2002). As a result, this state-of-practice review primarily encompasses accrued experiences from both the USA and Canada -two countries which have been devoting considerable attention to CEAM over the last two decades, and particularly since 2000.Included herein is a brief historical perspective on the practice of CEAM. Early practice focused on T Larry Canter is Principal, Environmental Impact Training, PO Box 9143, Horseshoe Bay, Texas 78657, USA, and also Professor of Civil Engineering and Environmental Science (Emeritus) at the University of Oklahoma, Oklahoma 73019-0470, USA; Email: envimptr@aol.com. Bill Ross is Professor of Environmental Science (Emeritus), Environmental Design, University of Calg...

Asphaltenes are the n-pentane or n-heptane insoluble fractions of crude oil that remain in solution under reservoir temperature and pressure conditions. They are destabilized and start to precipitate when the pressure, temperature, and/or composition changes occur during primary production. The precipitated asphaltene particles will then grow in size, and may start to deposit onto the production string and/or flowlines, causing operational problems. In this paper, our emphasis is to identify the first pressure and/or temperature conditions at which the asphaltene will start to precipitate for two reservoir oils. Four different laboratory techniques were independently used to define the onset of the asphaltene precipitation envelope. These methods are:gravimetric;acoustic resonance;light scattering; andfiltration. The gravimetric method was found to be precise, and within the accuracy of the analytical methods. However, the method was time consuming. The acoustic resonance technique (ART) was fast and less subjective, but it did not define the lower asphaltene boundary. The interpretation of the onset pressure from the near-infrared (NIR) light-scattering technique (LST) was subjective to a degree. However, the NIR response defined the upper and lower boundaries of the asphaltene envelope and the bubblepoint pressure, as did the gravimetric technique. In a manner similar to those of the gravimetric technique and LST, the filtration technique can also define the upper and lower asphaltene phase boundaries, in addition to the bubblepoint pressure. The filtration technique is fast compared to the gravimetric technique, but takes more time than the ART and LST methods. Introduction Asphaltenes remain in solution under reservoir temperature and pressure conditions. They start to precipitate when the stability of the colloidal dispersion is disturbed. This disturbance can be caused by changes in pressure, temperature, and/or composition of the oil. Precipitation and deposition of asphaltenes have reportedly caused operational problems, ranging from plugging of tubulars and flowlines(1–3) to clogging of production separators(4). Leontaritis and Mansoori present a comprehensive description of field problems caused by asphaltene deposition(5). Figure 1 schematically presents the asphaltene-related problems that may occur in the field. Asphaltene precipitation problems can be categorized as follows:Precipitation can be caused by the changes in temperature and/or pressure during primary depletion.Precipitation can be caused by blending or commingling of two noncompatible reservoir fluid streams (i.e., subsea completions), acid stimulation and/or enhanced recovery injection gases (CO2, H2S, or rich gas). The correct operating procedure to minimize the asphaltene problem is not well understood. We believe a better understanding of the fundamental processes leading to solids precipitation is a prerequisite to management and prevention of production problems. Primarily, two theoretical approaches have been presented in the literature to compute phase separations of asphaltene during primary production. These approaches include association modeling(6, 7) and calculation of asphaltene solubility parameters with the Flory Huggins polymer phase separation technique.(8, 9) Asphaltene destabilization caused by solvent injection and consequent alteration of the rock surface wettability have also been reported in the literature, but are not discussed here.(10).

The National Robotics Engineering Consortium and UltraStrip Systems Inc. have developed a highly flexible and productive robot to strip paint from large ships and other large ferro-magnetic structures based on the patents obtained by UltraStrip Systems, Inc. (US patents: 6,425,340; 5,849,099; 5,628,271). Removal of corrosion and coatings from large vessels has become a serious economic and environmental problem, and current practices are becoming infeasible. The M2000 robot removes paint from ships using ultrahigh pressure water jets and recovers the water and debris in an environmentally sound way. The addition of simple, easy-to-use, cruise control features to the robot has permitted significant increases in productivity, safety, and stripping quality.