US 11,867,036 B2
Insitu foam generation to fasten and increase oil production rates in gravity drainage CO2 gas injection
Zuhair AlYousef, Saihat (SA); Subhash Ayirala, Dhahran (SA); Ali Abdullah Altaq, Qatif (SA); Muhammad Majid Almajid, Qatif (SA); and Dong Kyu Cha, Dhahran (SA)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed on Jun. 23, 2021, as Appl. No. 17/355,908.
Prior Publication US 2022/0412197 A1, Dec. 29, 2022
Int. Cl. E21B 43/16 (2006.01); C09K 8/594 (2006.01); E21B 43/25 (2006.01); E21B 43/22 (2006.01)
CPC E21B 43/164 (2013.01) [C09K 8/594 (2013.01); E21B 43/25 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for recovering hydrocarbons from a hydrocarbon bearing formation, comprising:
introducing a first solution into a target zone of the hydrocarbon bearing formation, the first solution comprising a first salt;
introducing a second solution into the target zone of the hydrocarbon bearing formation, the second solution comprising a second salt and a foaming agent,
wherein the first salt and the second salt produce a nitrogen gas, and
wherein the nitrogen gas and the foaming agent produce a foam formed in-situ within the target zone;
maintaining the hydrocarbon bearing formation to propagate the foam to at least one high permeability zone in the hydrocarbon bearing formation to form a foam barrier; and
after forming the foam barrier, introducing CO2 into an upper portion of the formation gravitationally above the foam barrier, to form a gas cap having a gas front that is separated from the hydrocarbons by the foam barrier.