Optimization of steam-additive processes with DTS/DAS applications in heavy oil reservoirs

SPE Annual Technical Conference and Exhibition 2019, ATCE 2019 -- 30 September 2019 through 2 October 2019 -- -- 157070DTS/DAS applications provide key advantages in surveillance and better understanding of both unconventional and thermal operations in terms of key attributes including but not limited to conformance, wellbore integrity in better spatial and temporal terms. This study investigates the effects of CO2 in enhancing the steamflood process while incremental benefits are achieved through improved monitoring of the steamflood injection process using DTS/DAS applications using a completely synthetic but realistic reservoir model. A full-physics reservoir simulator is used to model the process. The technical and economic details of deployment of DTS/DAS as well as the steam-additive process are outlined in detail. Sensitivity study carried out on the model indicates the key attributes along with their significance. Athabasca bitumen properties are used. CO2 additive increases the steam chamber size but lowers the steam temperature while naptha/CO2 additives lower the viscosity, thus optimization study carried out the optimum operating levels of the additives not only in physical production/injection terms but also in terms of economics. The results indicate better reservoir management with DTS/DAS applications compared to the base case and injection can be monitored and adjusted better with such tools. DTS/DAS applications prove useful not only in terms of production performance but also in terms of economics. Physical properties of CO2 and naptha outline that the two have different dominant modes of improving recovery with steam-only injection. CO2 increases the extent of the steam chamber while lowering the steam temperature significantly. This study approaches the delicate process of additive use in steam processes while coupling the additional benefits of use of DTS/DAS applications in optimizing the recovery and the economics outlining the key attributes and the challenges and best practices in operations serving as a thorough reference for future applications. © 2019, Society of Petroleum Engineer