| CPC C09K 8/74 (2013.01) [C09K 8/54 (2013.01); E21B 41/02 (2013.01); E21B 43/25 (2013.01); C09K 2208/32 (2013.01)] | 15 Claims |
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1. An acid injection and fracturing method with downhole corrosion inhibition of an oil and gas well in a porous subterranean geological formation, comprising:
injecting an acidic treatment fluid into the oil and gas well at a first pressure through metal tubing into pores of the porous subterranean geological formation to react with and/or dissolve rock of the porous subterranean geological formation and thereby increase a permeability of the porous subterranean geological formation; then
fracturing the rock at a second pressure that is greater than the first pressure;
wherein the acidic treatment fluid is an aqueous solution comprising (i) a corrosion inhibitor composition comprising gelatin and an intensifier selected from the group consisting of CuI, KI, and formic acid, and (ii) 14 to 16 wt. % of HCl, based on a total weight of the acidic treatment fluid,
wherein the gelatin is present in the acidic treatment fluid in a concentration of 0.5 to 2.5 wt. % per total volume of the acidic treatment fluid,
wherein the intensifier is present in the acidic treatment fluid in a concentration in a range of from 0.01 to 0.05 wt. % per total volume of the acidic treatment fluid,
wherein the gelatin has a Bloom number in a range of from 50 to less than 220, and
wherein the gelatin has free carboxyl groups in a range of from 78 to 115 mmol per 100 g of protein.
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