Patent ID: 9611737
Date: 2017-04-04
CPC Classifications: E21B

Claim:
1. A method of fracturing or stimulating via injection of a fluid, a hydrocarbon-containing formation at discrete locations along a length of a wellbore situated in said formation, at regions within said formation where hydrocarbons are determined to be likely present and avoiding applying such methods to said formation in other regions along said wellbore, comprising the steps of: (i)placing within said wellbore, at a plurality of discrete intervals along a length thereof, fluid pressurization means which allow for supply of a pressurized fluid at each of said discrete intervals; (ii) applying, via said fluid pressurization means, said pressurized fluid at each of said discrete intervals, at a pressure below formation dilation pressure; (iii) sensing, via sensing means, for each discrete interval, a value or values indicative of reservoir characteristics at a region of said formation proximate said discrete interval and thereby compiling a plurality of values and associated discrete locations along said wellbore; (iv) determining, using said reservoir characteristics at said discrete intervals, said discrete intervals where hydrocarbons are likely present; and (v) applying cyclic fluid pressure pulses, at pressures above said formation dilation pressure, at one or more of said discrete intervals along said wellbore determined in step (iv) above, to assist in collection of oil in said wellbore; wherein said step of applying cyclic pressure fluid pulses via said fluid pressurization means at pressures above said formation dilation pressure comprises use of a tool, wherein said tool comprises: a cylindrical elongate member, having an uphole end and a mutually-opposite downhole end; a reservoir chamber, situated at said downhole end, said chamber bounded at an upstream end thereof by a slidable piston member; a tubular passageway means, extending substantially a length of said elongate member, in fluid communication with said reservoir chamber and providing fluid communication between a fluid inlet at said uphole end and said reservoir chamber; a fluid exit passage; a valve member contacted by said tubular passageway means, having an open position and a closed position, for allowing and preventing fluid flow from said fluid inlet to said fluid exit passage; biasing means biasing said slidable piston member against fluid in said reservoir chamber and further biasing said tubular passageway means against said valve member so as to bias said valve member to said open position which allows fluid to exit said tool via said fluid exit passage; wherein upon fluid being supplied to said fluid inlet at said upstream end and said valve member being in a closed position, fluid pressure in said reservoir chamber increases due to fluid supplied to said reservoir chamber from the fluid inlet via said tubular passageway means, and said slidable piston member is caused to move uphole against said biasing means and said biasing means then forces said tubular passageway means to move said valve member to said open position and allow fluid from said inlet area to exit the tool via said exit passage, thereby causing a drop in fluid pressure in both said tubular passageway means and said reservoir chamber, thereby causing said sliding piston to move downhole in said reservoir chamber and allowing said valve member to move to a closed position.