US 11,851,997 B2
System and method for optimized production of hydrocarbons from shale oil reservoirs via cyclic injection
Robert A. Downey, Centennial, CO (US)
Assigned to Shale Ingenuity, LLC, Centennial, CO (US)
Filed by Shale Ingenuity, LLC, Centennial, CO (US)
Filed on Apr. 9, 2021, as Appl. No. 17/226,956.
Claims priority of provisional application 63/008,322, filed on Apr. 10, 2020.
Prior Publication US 2021/0317733 A1, Oct. 14, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. E21B 43/25 (2006.01); E21B 43/16 (2006.01); E21B 43/26 (2006.01); E21B 43/40 (2006.01); E21B 49/00 (2006.01)
CPC E21B 43/255 (2013.01) [E21B 43/168 (2013.01); E21B 43/2605 (2020.05); E21B 43/2607 (2020.05); E21B 43/40 (2013.01); E21B 49/00 (2013.01); E21B 2200/20 (2020.05)] 12 Claims
OG exemplary drawing
 
1. A method for increasing recovery of oil from a shale reservoir utilizing a cyclic injection and production process, wherein the cyclic injection and production process (1) comprises a plurality of injection periods and a plurality of production periods, and (2) cycles alternatively between an injection period in the plurality of the injection periods and a production period in the plurality of production periods, wherein the method comprises steps of:
(a) determining a composition of a hydrocarbon-containing composition for injection, wherein the hydrocarbon-containing composition is in a liquid state at surface injection conditions;
(b) determining a fracture pressure of the shale reservoir at which the hydrocarbon-containing composition causes the shale reservoir to fracture;
(c) determining a maximum injection rate and a maximum injection pressure in a well to be utilized during the injection period, wherein the maximum injection pressure results in a near wellbore reservoir pressure that is at least the shale reservoir fracture pressure;
(d) injecting the hydrocarbon-containing composition into the shale reservoir during the injection period so as to create fractures and displace a portion of the hydrocarbon-containing composition into the created fractures, wherein
the injection period comprises a period of time during which the near wellbore reservoir pressure of the well reaches at least the shale reservoir fracture pressure, and while continuing with the injecting of the hydrocarbon-containing composition, the near wellbore reservoir pressure is maintained at or above the shale reservoir fracture pressure for a pre-determined period of time of the injection period;
(e) determining a maximum production rate of gases and liquids from the well and a minimum production pressure at the well to be utilized during the production period;
(f) producing the well to obtain produced hydrocarbon fluids during the production period in the plurality of production periods for a period of time such that the pressure at the well reaches the determined minimum production pressure;
(g) during the production period, assessing composition of the produced hydrocarbon fluids and utilizing a compositional reservoir simulation model to determine a composition of residual hydrocarbons in the shale reservoir;
(h) utilizing a hydrocarbon processing apparatus to recover a portion of the hydrocarbon-containing composition from the produced hydrocarbon fluids, wherein the hydrocarbon processing apparatus comprises equipment selected from a group consisting of stage separators, compressors, refrigeration units, joule-thompson units, fractionation and stabilization units; chemical additives storage and injection pumps; gauges, sensors, controls, supervisory control and data acquisition (SCADA) equipment, heat exchangers, coolers, vessels, and combinations thereof,
(i) processing the produced hydrocarbon fluids above ground with the hydrocarbon processing apparatus to remove (1) methane and ethane gases, (2) hydrocarbons containing hexanes, and (3) hydrocarbons having a molecular weight greater than hexane;
(j) determining a composition of an adjusted hydrocarbon-containing composition for injection based upon the composition of the residual hydrocarbons in the shale reservoir determined in step (g);
(k) adjusting the portion of the hydrocarbon-containing composition recovered utilizing the hydrocarbon processing apparatus to the composition of the adjusted hydrocarbon-containing composition and thereby forming an adjusted recovered portion of the hydrocarbon-containing composition;
(l) repeating steps (b) through (k) utilizing the adjusted recovered portion of the hydrocarbon-containing composition as the hydrocarbon-containing composition for injection.