An Innovative Approach to Heat Heavy Oil Formations by Means of Two Horizontally Interconnected Wells

Abstract

Abstract In the last years, several technologies have been developed to either allow or increase production from heavy oil fields. The greatest challenge is to reduce oil viscosity by heating in depth the formation. Despite the availability of many methods, there is no one that is at the same time technically efficient, economically profitable, environmentally-friendly and applicable to all types of heavy oil reservoirs. This still generates a large amount of research investments for the Major Oil Companies. Eni E&P has initiated an R&D project based on the innovative concept of interconnecting two horizontal wells. The main objective is to realize a closed circuit to allow the continuous circulation of a superheated fluid across a lengthy horizontal section. The heat transferred from the fluid to the formation will reduce viscosity of the heavy oil inside the reservoir and will improve its recovery. The fluid to be circulated will be "super heated" by means of thermodynamic solar energy. All the above make the method studied by Eni E&P applicable to almost all types of heavy oil deposits, characterized by a high technical-economical efficiency and highly eco-friendly. Several aspects are involved in the achievement of such a closed circuit and need to be considered while performing drilling, intersecting and tubing running operations. Specially fit for purpose well profiles and casing/open hole schemes are foreseen in order to correctly reach the reservoir with the intended hole section and align the two wells with a suitable "bridge" (casing or liner). Due to the very high temperature involved in this application, in the above mentioned R&D project there is consideration in developing new materials and welded casing pipes. This paper will describe the approach, the status of the project and the expected results.