Method to improve matrix acidizing in carbonates
AssigneeMobil Oil Corporation
InventorsAlfred R. Jennings, Jr., Lloyd G. Jones
Life of this patent
Estimating the term…
Abstract
A process for improved acidizing in carbonate formations, where controlled pulse fracturing (CPF) is utilized in combination with a retarded acid. The retarded acid comprises hydrochloric, formic, acetic acid or mixtures thereof which is placed in a wellbore adjacent the area to be treated. Said acid can contain retarders and corrosion inhibitors sufficient to make said acid stable in the wellbore. At least one CPF device is placed in said acid near the interval to be treated. Upon detonation of said device, acid is forced into the desired interval, thereby enhancing the acidizing treatment.
Claims16
A method for increasing the permeability of a formation which formation has at least one zone of lesser permeability and one zone of greater permeability where high energy impulse fracturing is used in combination with an inhibited acid comprising:
- (a) directing into a wellbore within said formation a pumpable solidifiable gel into the zone of the formation having the zone of greater permeability under conditions to selectively close pores in said greater permeability zone;
- (b) allowing said pumpable gel to solidify and form a gel plug within said wellbore which plug is sufficient to support a desired volume of acid;
- (c) placing an inhibited acid into said wellbore above said gel plug adjacent to said zone of lesser permeability;
- (d) suspending a canister containing a propellant into the wellbore substantially near said zone of lesser permeability;
- and
- (e) igniting said propellant which releases energy sufficient to form more than two simultaneous radial fractures in said zone of lesser permeability which also causes said acid to enter said fractures and thereafter react within said fractures, thereby increasing the permeability of said zone of lesser permeability.
A method for increasing the permeability of a formation, where high energy impulse fracturing is used in combination with an inhibited acid comprising:
- (a) placing an inhibited acid into a wellbore adjacent to the interval of the formation desired to be treated which acid is of strength sufficient to react with said formation;
- (b) suspending a canister containing a propellant into the wellbore substantially near said interval;
- and
- (c) igniting said propellant which releases energy sufficient to form more than two simultaneous radial fractures which also causes said acid to enter said fractures and thereafter react within said fractures, thereby increasing the permeability of said interval.
Dependencies are inferred from the claim text.