METHODS FOR PERFORMING FRACTURING AND ENHANCED OIL RECOVERY IN TIGHT OIL RESERVOIRS

摘要

A method of recovering oil from a reservoir is described herein. The methodincludesintroducing CO2 through a well bore into the reservoir, the well bore having abottom-holepressure greater than a fracture pressure of the reservoir to producefractureswithin the reservoir and greater than a minimum miscibility pressure betweenthe CO2and the oil to produce a miscible zone; stopping the introduction of CO2through the wellbore for a first period of time to reduce the bottom-hole pressure to be lessthan thefracture pressure and greater than the minimum miscibility pressure; re-introducing theCO2 to maintain the bottom-hole pressure to be less than the fracture pressureandgreater than the minimum miscibility pressure to maintain the miscible zone;shutting inthe well bore to promote displacement of the CO2 through the reservoir in adirectionaway from the well bore; and recovering the oil from the reservoir.