Similar to the steam assisted gravity drive (SAGD), the chemical assisted gravity drive combines two horizontal wells into a treatment framework. The upper well is used for continuous chemical injection while the lower horizontal well, typically with a 5 to 10m spacing, is used as a production well. As the formation heats up and the gases from the reaction rise, the heavy oil is heated, resulting in a reduced viscosity, and through gravity and gas pressure is driven towards the production well.
The use of a packer in the chemical injection well makes it possible to treat individual sections of the sand and thus achieve an optimal production pattern. As the binary mixtures can heat up a large area in a short time, its application is typically in cycles rather than a continuous process. The production however is a continuously. Contrary to steam injections, there is no risk of water flooding a well, as the residual products of the chemical reaction are gases such as oxygen or carbon dioxide..
In addition to the thermal treatment, the binary mixtures can be used in a high pressure environment to fracture the formation in order to create a bigger platform to be heated and more oil to be produced through the lower well.