US-12624278-B2 - Downhole methods and compositions used in such

US12624278B2US 12624278 B2US12624278 B2US 12624278B2US-12624278-B2

Abstract

A method of the invention prepares a hydrocarbon-bearing formation for stimulation. A bottom hole assembly comprising a plug and a perforation tool connected to a wireline is lowered into the wellbore. Acid is injected into the wellbore such that the acid is in direct contact with the perforation tool, wireline and casing of the wellbore. The plug is positioned downhole beyond a location where a first perforation area is to be made in the casing. The perforation tool is activated creating the first perforation area. The acid then contacts the first perforation area and cementitious debris generated from the casing being perforated. The perforation tool is next moved up-hole to a second location and the casing is again perforated to create a second perforation area. The acid also contacts the second perforated area and cementitious debris generated from the perforated casing. The perforation tool is lastly removed from the wellbore.

Inventors

Tom McLoughlin
Steven Scott Mann
Clay PURDY
Markus WEISSENBERGER

Assignees

DORF KETAL CHEMICALS FZE

Dates

Publication Date: 20260512
Application Date: 20240924
Priority Date: 20180511

Claims (14)

1 . A method to prepare a hydrocarbon-bearing formation for a stimulation operation, said method comprising the following steps: step a) providing a wellbore having a casing; step b) assessing at least a first location and a second location for perforation of said casing; step c) inserting a bottom hole assembly into said wellbore; said bottom hole assembly comprising a plug and a perforation tool and said bottom hole assembly being connected to a wireline; step d) injecting a spacer fluid into said wellbore; step e) injecting an acidic composition into said wellbore; wherein said acidic composition is in direct contact with said perforation tool, said wireline and said casing; step f) positioning and setting said plug in the wellbore at a position downhole but proximate to said first location: step g) positioning said perforation tool at said first location; step h) perforating said casing at said first location with the perforation tool thereby creating a first perforated area and a first cementitious debris; step i) causing said acidic composition to come into contact with said first perforated area and said first cementitious debris for a predetermined period of time to prepare the formation for said stimulation operation; step j) moving the perforation tool uphole to said second location; step k) perforating said casing at said second location with the perforation tool thereby creating a second perforated area and a second cementitious debris; step l) causing said acidic composition to come into contact with the second perforated area and said second cementitious debris for a predetermined period of time to prepare said formation for said stimulation operation; step m) removing the perforation tool from the wellbore; wherein said acid composition comprises an acid and a corrosion inhibitor package, said corrosion inhibitor package comprising at least two compounds selected from: Group D; Group E; Group F; Group G, where the at least two compounds are selected from different groups and wherein: Group D comprises compounds encompassed within the following general chemical description: sulfur-containing compounds; mercapto-compounds; organosulfur compounds reaction products of thiourea; thiodiglycol alkoxylates; Group E comprises compounds encompassed within the following general chemical description: nitrogen-containing surfactant; and non-ionic surfactant; Group F comprises compounds encompassed within the following general chemical description: morpholine; aminoalkyl imidazolines; sarcosine; two linked cyclic molecules with at least one nitrogen heterocycle including quinoline+benzyl, benzyl quinolinium chloride and derivatives thereof; imidazoline; and alkyl pyridine; Group G comprises compounds encompassed within the following general chemical description: aromatic ketone; amide; and phenyl ketone.
2 . The method according to claim 1 wherein the acid is selected from the group consisting of: mineral acids; organic acids; modified acids; synthetic acids; and combinations thereof.
3 . The method according to claim 1 wherein the acid is selected from the group consisting of: HCl; methanesulfonic acid; sulfamic acid; toluenesulfonic acid; HCl-alkanolamine; HCl-amino acid, including lysine.
4 . The method according to claim 1 wherein the Group D compound is selected from the group consisting of: thioglycolic acid; alkali metal thiosulfates; alkali metal thiosulfate hydrates; derivatives thereof and combinations thereof.
5 . The method according to claim 1 wherein the Group D compound is present in an amount in the range of from about 1% to about 20% by weight of the corrosion inhibitor package.
6 . The method according to claim 1 wherein the Group D compound is present in a corrosion-inhibiting additive of the present invention in an amount of about 5-10% by weight of the corrosion inhibitor package.
7 . The method according to claim 1 where the Group E compounds comprise nitrogen-containing surfactants selected from the group consisting of: alkyl amide surfactants, amine oxide surfactants, derivatives thereof, and combinations thereof.
8 . The method according to claim 1 wherein the Group F compound is selected from the group consisting of: amines having from 1 to 24 carbon atoms in each alkyl moiety.
9 . The method according to claim 8 wherein the Group F compound amine is selected from the group consisting of: ethylamine; diethylamine; trimethylamine; propylamine; dipropylamine; tripropylamine; mono-, di- and tripentylamine; mono-, di- and trihexylamine.
10 . The method according to claim 8 wherein the Group Famine is selected from the group consisting of: alkyl pyridines having from one to five nuclear alkyl substituents per pyridine moiety, such alkyl substituents having from one to 12 carbon atoms.
11 . The method according to claim 1 wherein the Group G compound is selected from the groups consisting of: acetophenone, mesityl oxide, 1-acetonaphthone, p-methoxyacetophenone, propiophenone, p-chloroacetophenone, isophorone, tetrolophenone, 2,4-pentanedione, a mixture of phenethyl alcohol and acetophenone, 2-acetylcyclohexanone, 2-acetonaphthone, 2-thienylketone, methyl isobutylketone, n-butyrophenone, acetone, 3,4-dihydro-1-(2H)-naphthalenone, 2-heptanone, diacetone alcohol, undecanone-2, and mixtures thereof; formaldehyde, benzaldehyde, heptanal, propanal, hexanal, octanal, decanal, hexadecanal, cinnamaldehyde; and rendered animal fat, octanoic acid, myristic acid, pelargonic acid, abietic acid, lauric acid, oleic acid, caprylic acid, tall oil acid, ethoxylated coco, fatty acid, ethoxylated oleic acid, ethoxylated rosin fatty acid, tall oil reacted with propylene oxide and ethylene oxide, 2-methyl pyridine, 4-methyl pyridine, 2-methyl quinoline, 4-methyl quinoline, and mixtures thereof.
12 . The method according to claim 1 wherein: the corrosion inhibition package can be selected from the following combinations of group where reactions occur between compounds of said groups: a compound of Group F reacted with a compound of Group G.
13 . The method according to claim 1 wherein: the order of step h) and step i) is reversed.
14 . The method according to claim 1 wherein: step i), step j), and step k) are repeated at least once.

Description

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation in part of U.S. application Ser. No. 18/614,191 filed on Mar. 22, 2024, which is a continuation in part of U.S. Ser. No. 18/583,037 filed on Feb. 21, 2024; which is a continuation of U.S. application Ser. No. 18/069,091, filed Dec. 20, 2022, now U.S. Pat. No. 12,018,210 issued on Jun. 25, 2024; which is a Continuation of U.S. application Ser. No. 17/054,439, filed Nov. 10, 2020, now U.S. Pat. No. 11,591,511, issued on Feb. 28, 2023; which is a national stage application under 35 U.S.C. 371 of PCT Application No. PCT/CA2019/000067 having an international filing date of May 10, 2019, which designated the United States, which PCT application claimed the benefit of Canadian Application Serial No. 3,004,675, filed May 11, 2018. The entire specifications and figures of the above-referenced applications are hereby incorporated in their entireties by reference. FIELD OF THE INVENTION This invention relates to method for performing downhole processes in the oil and gas industry, more specifically to various corrosion inhibitor compositions and processes to enhance well productivity for substantially reducing stimulation time and water use during hydraulic fracturing operations. BACKGROUND OF THE INVENTION In the oil & gas industry, stimulation with an acid is performed on a well to increase or restore production. In some instances, a well initially exhibits low permeability, and stimulation is employed to commence production from the reservoir. In other instances, stimulation or remediation is used to further encourage permeability and flow from an already existing well that has become under-productive due to scaling issues or formation depletion. Acidizing is a type of stimulation treatment which is performed above or below the reservoir fracture pressure in an effort to initiate, restore or increase the natural permeability of the reservoir. Acidizing is achieved by pumping acid, predominantly hydrochloric acid, into the well to dissolve typically limestone, dolomite and calcite cement between the acid insoluble sediment grains of the reservoir rocks or to treat scale accumulation. There are three major types of acid applications: matrix acidizing, fracture acidizing, and breakdown acidizing (pumped prior to a fracturing pad or cement operation in order to assist with formation breakdown (reduce fracture pressures, increased feed rates), as well as clean up left over cement in the well bore or perforations. A matrix acid treatment is performed when acid is pumped into the well and into the pores of the reservoir formation below the fracture pressure. In this form of acidization, the acids dissolve the sediments formation and/or mud solids that are inhibiting the permeability of the rock, enlarging the natural pores of the reservoir (wormholing) and stimulating the flow of hydrocarbons to the wellbore for recovery. While matrix acidizing is done at a low enough pressure to keep from fracturing the reservoir rock, fracture acidizing involves pumping acid into the well at a very high pressure, physically fracturing the reservoir rock and etching the permeability inhibitive sediments. This type of acid treatment forms channels or fractures through which the hydrocarbons can flow, in addition to forming a series of wormholes. In some instances, a proppant is introduced into the fluid which assists in propping open the fractures, further enhancing the flow of hydrocarbons into the wellbore. There are many different mineral and organic acids used to perform an acid treatment on wells. The most common type of acid employed on wells to stimulate production is hydrochloric acid (HCl), which is useful in stimulating carbonate reservoirs. It has been estimated that fracking can improve the production of a well by at least 10-20%. Also, as is well known to the person of ordinary skill in the art, a well can be fracked multiple times during its production life. The process of hydraulic fracturing or fracking requires the following steps. Once the determination of the wellbore's integrity has been assessed, the location of the perforations is determined. Subsequently, after a cement liner is in place, one must clear out the debris, and pump a plug and perforating guns to a desired depth and location. The plug is set slightly beyond the desired location to be stimulated and then the cemented liner in that zone is perforated by using perforating guns, creating a path for fracking fluid to be forced into the shale formation. The final stage prior to fracking requires the use of perforating guns, typically a string of shaped charges lowered to a predetermined location within the wellbore. Once in position, the perforating gun is discharged and perforates the casing. According to the conventional process, after perforation stage is completed, the tools are removed from the well. A ball is pumped down to isolate the zones below the plug. This process applies to