Additives for oil recovery from reservoirs
AssigneeENI S.p.A.
InventorsLucilla Del Gaudio, Thomas Paul Lockhart, Emanuele Vignati
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Abstract
The invention relates to the use of quaternary polyamines having formula (I) for the recovery of oil from reservoirs formula (I), wherein n>=1 R1 represents H, CH3, CH2CH3, CnH2n+1 R2 represents H2CHOHCH2, CH2, CH2CH═CH2 R3 represents CH3, CH2CH3, CnH2n+1 R4 represents CH2, CH2CH═CH2 when R2 and R4 are allyl group, they can jointly form aliphatic cyclic structures, the ratio between the carbon atoms and nitrogen atoms (C/N) ranges from 2 to 30.
Claims25
A method for increasing oil recovery from carbonate reservoirs having low permeability, comprising:
- preparing a solution and subsequently injecting the solution into a well comprising crude oil where the crude oil has an interfacial tension >10 mN/m and an acid number higher than 0.25to modify a wettability of a rock from an oil-wet condition to a water-wet condition without lowering a water-oil interfacial tension,
- wherein the solution comprises one or more quaternary polyamines having formula (I)
- wherein n >=1
- R1 represents H, CH3, CH2CH3, CnH2n+1
- R2 represents H2CHOHCH2, CH2, CH2CH═CH2
- R3 represents CH3, CH2CH3, CnH2n+1
- R4 represents CH2, CH2CH═CH2
- wherein when R2 and R4 are allyl group, they optionally jointly form aliphatic cyclic structures, wherein a ratio between the carbon atoms and nitrogen atoms (C/N) ranges from 2 to 30, and
- wherein the solution comprises the one or more quaternary polyamines at a concentration in a range of from 0.01% to 20% by weight with respect to the total weight of the solution, and wherein the one or more quaternary polyamines in the solution complex one or more acid components present in the crude oil absorbed on rock forming the carbonate reservoir thereby removing the acid components from the rock.
A method for increasing oil recovery from a carbonate reservoir having low permeability, comprising:
- injecting a solution into a well present in the carbonate reservoir, wherein the carbonate reservoir comprises a crude oil having an interfacial tension of >10mN/m and an acid value higher than 0.25,
- wherein the solution comprises one or more quaternary polyamines having formula (I)
- wherein n >=1
- R1 represents H, CH3, CH2CH3, CnH2n+1
- R2 represents H2CHOHCH2, CH2, CH2CH═CH2
- R3 represents CH3, CH2CH3, CnH2n+1
- R4 represents CH2, CH2CH═CH2
- wherein when R2 and R4 are allyl group, they optionally jointly form aliphatic cyclic structures,
- wherein a ratio between the carbon atoms and nitrogen atoms (C/N) ranges from 2 to 30, and
- wherein the solution comprises the one or more quaternary polyamines at a concentration in a range of from 0.01% to 20% by weight with respect to the total weight of the solution, and wherein the one or more quaternary polyamines in the solution complex one or more acid components present in the crude oil absorbed on rock forming the carbonate reservoir thereby removing the acid components from the rock.
Dependencies are inferred from the claim text.