Hydrocarbon recovery facilitated by in situ combustion

A process for hydrocarbon recovery from an oil sands reservoir comprising:

• performing a steam assisted gravity drainage operation by:
• injecting steam in a steam injection well of a steam assisted gravity drainage well pair and continuing to inject steam to establish fluid communication between the steam injection well and an oxidizin as injection well that includes an oxidizin as injection well segment that is spaced generally above the steam injection well segment;
• producing hydrocarbons from a hydrocarbon production well of the steam assisted gravity drainage well pair, the hydrocarbon production well including a generally horizontal production well segment disposed generally parallel to and vertically below a generally horizontal steam injection well segment of the steam injection well such that the steam injection well segment is disposed generally vertically between the production well segment and the oxidizing gas injection well segment;
• in response to determining that the steam injected in the steam injection well reaches the oxidizing gas injection well or is near a top of the oil sands reservoir, discontinuing performing steam assisted gravity drainage;
• injecting an oxidizing gas into the oil sands reservoir through the oxidizing gas injection well, the oxidizing gas supporting in situ combustion in the reservoir;
• and
• utilizing the steam assisted gravity drainage well pair to recover hydrocarbons mobilized by the in situ combustion, by:
• producing combustion gases through steam injection well of the steam assisted gravity drainage well pair;
• and
• recovering the mobilized hydrocarbons from the reservoir through the hydrocarbon production well of the steam assisted gravity drainage well pair.