US 11,905,461 B2
Methods for foam stimulation
Varadarajan Dwarakanath, Houston, TX (US); Taimur Malik, Houston, TX (US); Lin Zuo, Richmond, CA (US); Jimin Daniel Zhou, Richmond, CA (US); Nabijan Nizamidin, Houston, TX (US); Gregory A. Winslow, Houston, TX (US); Reza Banki, Moon, PA (US); and Mohamad Salman, Houston, TX (US)
Assigned to CHEVRON U.S.A. INC., San Ramon, CA (US)
Filed by Chevron U.S.A. Inc., San Ramon, CA (US)
Filed on Jul. 7, 2020, as Appl. No. 16/922,999.
Claims priority of provisional application 62/871,187, filed on Jul. 7, 2019.
Prior Publication US 2021/0002444 A1, Jan. 7, 2021
Int. Cl. E21B 43/16 (2006.01); C09K 8/60 (2006.01); C09K 8/94 (2006.01)
CPC C09K 8/602 (2013.01) [C09K 8/94 (2013.01); E21B 43/166 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for stimulating an unconventional subterranean formation comprising:
(a) providing an existing wellbore in fluid communication with an unconventional subterranean formation, wherein the existing wellbore has a pressure that is less than original reservoir pressure;
(b) injecting a foamed composition through the existing wellbore into the unconventional subterranean formation, the foamed composition comprising a surfactant package comprising a primary foaming surfactant, wherein the foamed composition is injected at a pressure and flowrate effective to increase the existing wellbore pressure;
(c) contacting the foamed composition with a rock matrix of the unconventional subterranean formation for a period of time; and
(d) producing fluids from the unconventional subterranean formation through the wellbore;
wherein step (b) comprises:
combining a foam precursor solution with an expansion gas to form the foamed composition above ground, and injecting the foamed composition through the existing wellbore into the unconventional subterranean formation; or
combining a foam precursor solution with an expansion gas downhole to form the foamed composition in situ within the existing wellbore.