Patent ID: 8746334
Filing Date: 2014-06-10
Classification: C09K,E21B

Abstract:
1. A post cold heavy oil production with sand (“CHOPS”) microbial enhanced oil recovery (“MEOR”) method comprising: (a) selecting a well in communication with a reservoir having at least one wormhole and that is being subjected to or has completed primary CHOPS production; (b) determining whether the reservoir contains a sufficient amount of a gas-producing indigenous microbe to enhance oil recovery by re-pressurizing a drainage portion of the well to a target pressure or by generating a target amount of gas; (c) when the reservoir does not contain a sufficient amount of the indigenous microbe, then preparing an injectant comprising a sufficient amount of a gas-producing microbe to re-pressurize the drainage portion of the well to the target pressure or to generate the target amount of gas, a nutrient suitable for the microbe, and a fluid base; (d) when the reservoir does contain a sufficient amount of the gas producing indigenous microbe, then preparing an injectant comprising a suitable nutrient for the indigenous microbe and the fluid base; (e) injecting the injectant through the well and into the at least one wormhole in the reservoir; (f) shutting in the well until the pressure in the well reaches the target pressure or the target amount of gas is generated; and (g) producing oil from the well.