Method for developing an oil bearing formation

Abstract

Rows of horizontal production wells and rows of horizontal injection wells are drilled and alternating in a formation. The horizontal production wellbores and the horizontal injection wellbores are placed in the direction of a minimum horizontal stress in the formation. Within casing strings of the wells, at least two hydraulic frac ports are installed and multi-stage fracturing is performed through them in the production wells and in the injection wells in such way that fractures are formed along each production well and along each injection well in a direction perpendicular to the horizontal wellbore, the hydraulic fractures in the injection wells are offset from the hydraulic fractures in the production wells. The production and the injection wells are put into operation by injecting a fluid into the injection wells, a flow rate and/or a volume of the injected fluid are controlled in such a way that the injection pressure is below a fracturing pressure.

1 . A method for developing an oil bearing formation, the method comprising:
 drilling within the formation alternating rows of horizontal production wells and rows of horizontal injection wells, the rows being placed at a first distance from each other, both horizontal production wellbores and horizontal injection wellbores are arranged in a direction of a minimum horizontal stress in the formation so as to provide hydraulic fractures perpendicular to the direction of the horizontal wellbores,   providing at least two frac ports at casing strings in the injection wells and in the production wells, the frac ports being spaced at a second distance from each other and providing fluid communication between the wells and the formation,   performing multi-stage hydraulic fracturing through the frac ports in the production and the injection wells so that multiple fractures are placed along each horizontal production well and each injection well perpendicularly to the direction of the horizontal wellbore, so that the hydraulic fractures of the injection wells are offset from the hydraulic fractures of the production wells by a third distance,   putting the production and the injection wells into operation by injecting a fluid into the injector wells and controlling a fluid injection rate and/or a fluid injection volume so that an injection pressure is maintained below a fracturing pressure.   
     
     
         2 . The method of  claim 1 , wherein the frac ports are capable of repeated opening and closing, and the fluid injection rate and/or the fluid injection volume are controlled by opening and closing the frac ports. 
     
     
         3 . The method of  claim 1 , wherein the hydraulic fractures of the injection wells are offset from the hydraulic fractures of the production wells by a half of the distance between the hydraulic fractures. 
     
     
         4 . The method of  claim 1 , wherein in case of an open hole completed well each frac port is located between two frac packers is such way that a distance between the frac packers is at least twenty times less that the distance between the two neighboring frac ports. 
     
     
         5 . The method of  claim 2 , wherein the frac ports are opened and closed with a coiled tubing, rigid wire or/and a wireline tractor.