"Creating Value Through Surveillance" was the theme of the SPE Applied Technology Workshop (ATW) on reservoir surveillance held 15–18 November 2006 in Phuket, Thailand. A total of 58 oilfield professionals, representing 32 organizations from 12 different countries, attended the ATW, which focused on the essential place of surveil-lance in reservoir management and on how to ensure that surveillance delivers quantifiable value that is clearly recognized. Following opening comments by workshop Cochairperson Gordon Springate (Chevron), keynote speaker Omar Al-Husaini, Acting General Manager, Drilling and Work over, Saudi Aramco, gave an incisive overview of the key surveillance technologies his organization is using to enhance production and recovery in an increasingly stretched global oil market. His comments on technical capability, geosteering technology, smart completions, and real-time field management set the stage for the discussions to come. A number of key themes developed over the course of the workshop:The inability to achieve effective use of surveillance information if organizations lack focused plans, people, and processes to manage such dataThe need for defined methods to establish the value of surveillanceThe effective use of high- and low-tech processes in reservoir surveillanceThe importance of managing large volumes of data and integrating them into reservoir management Reinforcing the importance of point No. 1, the key takeaways for more than half of the participants involved people, systems, and processes. The value theme was especially developed in Sessions 2 and 3. Session 2 encompassed discussions on the value of the intelligent wellbore (Jim Walker, Baker Hughes), probabilistic approaches to assessing the value of information (John Weber, Murphy), multiple uses of electric-submersible-pump monitoring data (Dan Saenz, Schlumberger), and the value resulting from effective workflows and integrated decision making in a mature waterflood (Rozaida Affendi, ExxonMobil). The subsequent breakout period (Session 3), led by ATW Cochairperson Nick Last (Advanced Well Technologies), enabled participants to put some of those concepts into practice during a group exercise on assessing the value of information. An effective poster session (Session 5) was put together by the contributors and successfully organized by Robert Pahmiyer (Halliburton). Among the several poster topics were production-logging applications in stacked sand reservoirs and the difficulties of implementing a genuine smart field. The effective use of fit-for-purpose technologies and data-management and -integration issues, were examined in sessions 4, 6, and 7. Kicking off Session 4, Brian Smart (Daylight Resources Trust) demonstrated the value of early application of simple analytical techniques to routine data. Following this was the presentation of a water-injection-surveillance case study by Mohamad Syukairy Supian (Petronas Carigali), which generated discussion on the importance of questioning and refining initial reservoir-management objectives as surveillance data accumulates. Chawiwan Jiraratchwaro (PTTEP) described how surveillance data from a stacked-sand gas field are used to characterize and manage water production, while Wong Chun Seng (Petronas Carigali) explained how effective surveillance has allowed continuous improvement of acid treatments in a field beset by scaling problems.