US 11,867,038 B2
Thickened CO2 in gravity drainage gas injection processes
Zuhair Al-Yousif, Saihat (SA); Subhash Ayirala, Dhahran (SA); Muhammad Majid Almajid, Al Qatif (SA); Dong Kyu Cha, Dhahran (SA); and Ming Han, Dhahran (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Dec. 7, 2021, as Appl. No. 17/643,067.
Prior Publication US 2023/0175366 A1, Jun. 8, 2023
Int. Cl. E21B 43/16 (2006.01); E21B 43/30 (2006.01)
CPC E21B 43/164 (2013.01) 24 Claims
OG exemplary drawing
 
1. A method for oil recovery, comprising:
injecting thickened CO2 into the top of a reservoir containing oil, wherein the thickened CO2 comprises a thickener comprising a mixture of a copolymer with propylene carbonate, allyl ethyl carbonate, dimethyl carbonate, white oil, silicon, oil, or petroleum ether, or combinations thereof;
forming an interface between the thickened CO2 and the oil;
mobilizing the oil with unthickened CO2, wherein the unthickened CO2 is injected after the thickened CO2; and
recovering the oil with a recovery well drilled below the reservoir.