Transcripción del resumen del autor. Steam-assisted gravity drainage (SAGD) has been improved consistently by experimenting with various solutions in both oil sands and heavy-oil fields in Canada (Butler 1994; Singhal et al. 1998). The SAGD process consists of two stacked horizontal wells and is proven technology in heavy-oil fields (Butler and Yee 2000). Employing the same concept of gravity drainage, SAGD-well placement convention has been revisited and challenged many times (Birrell and Putnam 2000; Edmunds 1991; Parappilly and Zhao 2009). Known to the industry, the cross-SAGD (also called XSAGD) (Stalder 2007) and J-shaped well steam-assisted gravity drainage (JAGD) (Larter et al. 2008) processes are two examples of fit-for-purpose well design and recovery schemes that require unique drilling practices. The Celtic pool, located in Lloydminster, Saskatchewan, is an active Husky Energy Incorporated (Husky) thermal field that includes 31 SAGD well pairs. In this heavy-oil pool, one of the SAGD well pairs (I3/I4; Well I3 as producer and Well I4 as the injector) experienced production downtime soon after coming into service. Following numerous unsuccessful service jobs, several re-entry options were suggested in order to recover remaining reserves. These included sidetracking Well I3, redrilling a new well from the same pad location, or commencing a new well from a different surface location. These cases were ranked, and in 2010, on the basis of a drilling-risk assessment, the new horizontal producer well (I3A) was drilled close to the existing well pair. Well I3A was placed counter currently below the existing injector well (I4) and set successfully parallel to the abandoned Well I3. Steam conditioning was completed in the first quarter (Q) of 2011, and the new SAGD well pair (I3A/I4) has been put on production successfully. The new well pair was positioned in the opposite direction of a conventional SAGD-well-pair placement. This paper presents the original I3/I4 pair performance, the challenges, results of redrilling Well I3A, reservoir-simulation study, and recent field production of the I3A/I4 SAGD well pair.

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