Amino inhibitor for drilling fluid as well as preparation method and application thereof

Abstract

The invention belongs to the field of treating agents for oil field drilling fluid, and particularly relates to an amino inhibitor for drilling fluid as well as a preparation method and application of the amino inhibitor. The amino inhibitor for the drilling fluid provided by the invention contains a compound with a structure as shown in a formula (I), in the formula (I), R is C1-C10 alkyl, n is an integer between 1 and 10, and m is an integer between 5 and 200. The inhibitor provided by the invention contains the compound with the structure as shown in the formula (I), amino groups in the compound with the structure as shown in the formula (I) are distributed on a molecular main chain, and the temperature resistance is high; the compound with the structure as shown in the formula (I) contains a large amount of amido and hydroxyl, and can be adsorbed on the surface of shale or enter crystal lattices to tighten a crystal layer, reduce hydration and dispersion of the shale and keep the well wall stable in the drilling process. In addition, during synthesis and preparation of the inhibitor, reaction conditions are mild and easy to control, a chain growth terminator does not need to be added, and the product is not prone to cross-linking and good in quality stability. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of treating agents for oilfield drilling fluids, and in particular relates to an amine-based inhibitor for drilling fluids, a preparation method and application thereof. Background Art

[0002] During the drilling process, wellbore instability is the main factor causing downhole complexity, especially in strata containing large sections of shale. Due to the hydration and dispersion of shale, wellbore collapse is very frequent. According to statistics, wellbore instability caused by hydration and dispersion of shale accounts for more than 90% of the incidence of wellbore instability. Inhibitors are a common treatment agent for drilling fluids that can inhibit the hydration and dispersion of shale and maintain the stability of the wellbore. Common drilling fluid inhibitors mainly include asphalt, polymers and inorganic salts. However, asphalt is not conducive to environmental protection, silicates will make it difficult to control the rheology of drilling fluids, potassium salts are used in large quantities, and polyethylene glycols have relatively poor inhibition performance. Amine inhibitors are currently the best inhibitor variety in field applications, with advantages such as low dosage and strong inhibition performance.

[0003] Chinese patent application number 201510534350.0 discloses a polyamine inhibitor and a preparation method thereof, which is obtained by reacting a polyamine compound with epichlorohydrin; Chinese patent application number 201110313847.1 discloses a polyamine inhibitor and a preparation method thereof, which is obtained by reacting a terminal diamine, a cyclic ether and epichlorohydrin. The amine compounds used in the above two schemes mainly contain primary amines and secondary amines, which are prone to severe crosslinking when reacting with epichlorohydrin, the reaction conditions are difficult to control, and the product quality stability is poor. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an amine inhibitor for drilling fluid and a preparation method and application thereof. The inhibitor provided by the present invention has strong inhibitory performance, good compatibility with drilling fluid, amine groups are distributed on the main chain of the molecule, and has good temperature resistance, and is very suitable for application in high-temperature resistant water-based drilling fluid systems; and the preparation conditions of the inhibitor are mild and easy to control, without the need to add a chain growth terminator, the product is not easy to cross-link, and has good quality stability.

[0005] The present invention provides an amine-based inhibitor for drilling fluid, wherein the amine-based inhibitor for drilling fluid contains a compound having a structural formula (I):

[0006]

[0007] In formula (I), R is C 1 ~C 10 wherein n is an integer between 1 and 10, and m is an integer between 5 and 200.

[0008] Preferably, the R is -CH3 or -CH 2 CH 3 .

[0009] Preferably, n is an integer between 2 and 4.

[0010] Preferably, m is an integer between 5 and 100.

[0011] Preferably, the amine-based inhibitor for drilling fluid further contains a liquid medium; the solid content of the amine-based inhibitor for drilling fluid is 10 to 50 wt%.

[0012] The present invention provides a method for preparing the amine-based inhibitor for drilling fluid described in the above technical solution, comprising the following steps:

[0013] The amino compound of formula (i) is mixed with epichlorohydrin in a liquid medium to react to obtain an amine inhibitor for drilling fluid;

[0014]

[0015] In formula (i), R is C 1 ~C 10 wherein n is an integer between 1 and 10.

[0016] Preferably, the amino compound is N,N-dimethylethylenediamine, N,N-dimethylpropylenediamine, N,N-dimethylbutylenediamine, N,N-diethylethylenediamine, N,N-diethylpropylenediamine or N,N-diethylbutylenediamine.

[0017] Preferably, the molar ratio of the amino compound to epichlorohydrin is 1:(0.5-1).

[0018] Preferably, the temperature of the mixed reaction is 40-70° C.; the time of the mixed reaction is 0.5-2 h.

[0019] The present invention provides a drilling fluid, wherein the drilling fluid contains the amine inhibitor for drilling fluid described in the above technical solution or the amine inhibitor for drilling fluid prepared by the preparation method described in the above technical solution.

[0020] Compared with the prior art, the present invention provides an amine inhibitor for drilling fluid and a preparation method and application thereof. The amine inhibitor for drilling fluid provided by the present invention contains a compound of formula (I), wherein R is C 1 ~C 10alkyl, n is an integer between 1 and 10, and m is an integer between 5 and 200. The inhibitor provided by the present invention contains a compound of the structure of formula (I), has strong inhibitory performance, and good compatibility with drilling fluid; the amine groups in the compound of the structure of formula (I) are distributed on the main chain of the molecule, and have strong temperature resistance; the compound of the structure of formula (I) contains a large number of amine groups and hydroxyl groups, which can be adsorbed on the surface of shale or enter the interior of the crystal lattice, tighten the crystal layer, reduce the hydration and dispersion of shale, and maintain the stability of the well wall during drilling. In addition, the inhibitor provided by the present invention has mild reaction conditions during synthesis and preparation, is easy to control, does not need to add chain growth terminator, is not easy to cross-link, and has good quality stability. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention provides an amine-based inhibitor for drilling fluid, wherein the inhibitor contains a compound having a structure of formula (I):

[0023]

[0024] In formula (I), R is C 1 ~C 10 wherein n is an integer between 1 and 10, and m is an integer between 5 and 200.

[0025] In the amine-based inhibitor for drilling fluid provided by the present invention, in the compound of formula (I), R can be specifically C 1 Alkyl (i.e., -CH 3 ), C 2 Alkyl (i.e., -CH 2 CH 3 ), C 3 Alkyl, C 4 Alkyl, C 5 Alkyl, C 6 Alkyl, C 7 Alkyl, C 8 Alkyl, C 9 Alkyl or C 10 Alkyl, preferably -CH 3 or -CH 2 CH 3 .

[0026] In the amine inhibitor for drilling fluid provided by the present invention, in the compound of formula (I), n can be specifically 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, preferably an integer between 2 and 4.

[0027] In the amine inhibitor for drilling fluid provided by the present invention, in the compound of formula (I), m can be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200, preferably an integer between 5 and 100.

[0028] In the amine-based inhibitor for drilling fluid provided by the present invention, in order to facilitate the addition and use of the inhibitor in the drilling fluid, the amine-based inhibitor for drilling fluid preferably also contains a liquid medium, and the liquid medium includes but is not limited to water; the solid content of the amine-based inhibitor for drilling fluid is preferably 10 to 50wt%, specifically 10wt%, 12wt%, 15wt%, 17wt%, 20wt%, 23wt%, 25wt%, 27wt%, 30wt%, 32wt%, 35wt%, 37wt%, 40wt%, 42wt%, 45wt%, 47wt% or 50wt%.

[0029] The amine inhibitor for drilling fluid provided by the present invention contains a compound of the structure of formula (I), has strong inhibitory performance, and good compatibility with drilling fluid; the amine groups in the compound of the structure of formula (I) are distributed on the main chain of the molecule, and have strong temperature resistance; the compound of the structure of formula (I) contains a large number of amine groups and hydroxyl groups, which can be adsorbed on the surface of shale or enter the interior of the crystal lattice, tighten the crystal layer, reduce the hydration and dispersion of shale, and keep the well wall stable during drilling.

[0030] The present invention also provides a method for preparing the amine inhibitor for drilling fluid described in the above technical solution, comprising the following steps:

[0031] The amino compound of formula (i) is mixed with epichlorohydrin in a liquid medium to react to obtain an amine inhibitor for drilling fluid;

[0032]

[0033] In formula (i), R is C 1 ~C 10 wherein n is an integer between 1 and 10.

[0034] In the preparation method provided by the present invention, the chemical reaction process involved is specifically as follows:

[0035]

[0036] In the preparation method provided by the present invention, in the amino compound of formula (i), R can be specifically C 1 Alkyl (i.e., -CH 3 ), C 2 Alkyl (i.e., -CH 2 CH 3 ), C 3 Alkyl, C 4 Alkyl, C 5 Alkyl, C 6 Alkyl, C 7 Alkyl, C 8 Alkyl, C 9 Alkyl or C 10 Alkyl, preferably -CH 3 or -CH 2 CH 3 ; The n can specifically be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, preferably an integer between 2 and 4.

[0037] In the preparation method provided by the present invention, the amino compound can be more specifically selected from N,N-dimethylethylenediamine, N,N-dimethylpropylenediamine, N,N-dimethylbutylenediamine, N,N-diethylethylenediamine, N,N-diethylpropylenediamine or N,N-diethylbutylenediamine.

[0038] In the preparation method provided by the present invention, the molar ratio of the amino compound to epichlorohydrin is preferably 1:(0.5-1), specifically 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1.

[0039] In the preparation method provided by the present invention, the liquid medium includes but is not limited to water; the amount of the liquid medium is determined according to the solid content of the amine-based inhibitor for drilling fluid to be prepared, and the solid content is the percentage of the total mass of the amino compound and epichlorohydrin to the total mass of the amino compound, epichlorohydrin and the liquid medium.

[0040] In the preparation method provided by the present invention, the temperature of the mixed reaction is preferably 40-70°C, specifically 40°C, 42°C, 45°C, 47°C, 50°C, 52°C, 55°C, 57°C, 60°C, 62°C, 65°C, 67°C or 70°C; the time of the mixed reaction is preferably 0.5-2h, specifically 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h.

[0041] In the preparation method provided by the present invention, the specific process of the mixed reaction is preferably: first dissolving the amino compound in a liquid medium to obtain an amino compound solution; then slowly adding epichlorohydrin to the amino compound solution under stirring conditions; after the addition of epichlorohydrin, heating to the reaction temperature for reaction; after the reaction is completed, cooling to obtain an amine-based inhibitor for drilling fluid with a certain solid content. The reaction temperature corresponds to the temperature of the mixed reaction described above; the time for the reaction after heating to the reaction temperature corresponds to the time of the mixed reaction described above.

[0042] The preparation method of the amine-based inhibitor for drilling fluid provided by the present invention has mild reaction conditions, is easy to control, does not need to add a chain growth terminator, and the inhibitor product is not easy to cross-link and has good quality stability.

[0043] The present invention also provides a drilling fluid, comprising a drilling fluid base slurry and an inhibitor, wherein the inhibitor is the amine-based inhibitor for drilling fluid described in the above technical solution or the amine-based inhibitor for drilling fluid prepared by the preparation method described in the above technical solution.

[0044] In the drilling fluid provided by the present invention, the drilling fluid base slurry contains water and bentonite; the drilling fluid base slurry also preferably contains other functional components, including but not limited to one or more of temperature-resistant and salt-resistant polymer filtrate reducer (MMT), low-viscosity sodium carboxymethyl cellulose (Lv-cmc), sulfonated phenolic resin (SMP) and sulfonated lignite (SMC).

[0045] In the drilling fluid provided by the present invention, the added content of the inhibitor is preferably 0.1-5wt%, more preferably 0.5-2wt%, specifically 0.5wt%, 1wt%, 1.5wt% or 2wt%.

[0046] For the purpose of greater clarity, the invention is described in detail through the following examples.

[0047] Example 1

[0048] 1 mol of N,N-dimethylethylenediamine was dissolved in 574 g of deionized water, mixed evenly and added to a reaction container, 0.6 mol of epichlorohydrin was slowly added under stirring at room temperature, and after the epichlorohydrin was added, the temperature in the reaction container was controlled at 50° C. to react for 1 hour, and cooled to room temperature to obtain an amine inhibitor for drilling fluid with a solid content of 20%, the chemical structure of which is shown in the following formula:

[0049]

[0050] Among them, m=30.

[0051] Example 2

[0052] 1 mol of N,N-dimethylbutylene diamine was dissolved in 313 g of deionized water, mixed evenly and added to a reaction container, 1 mol of epichlorohydrin was slowly added under stirring at room temperature, after the epichlorohydrin was added, the temperature in the reaction container was controlled at 40° C. to react for 2 h, and cooled to room temperature to obtain an amine inhibitor for drilling fluid with a solid content of 40%, the chemical structure of which is shown in the following formula:

[0053]

[0054] Wherein, m=100.

[0055] Example 3

[0056] 1 mol of N,N-diethylpropylenediamine was dissolved in 1586 g of deionized water, mixed evenly and added to a reaction container, 0.5 mol of epichlorohydrin was slowly added under stirring at room temperature, after the epichlorohydrin was added, the temperature in the reaction container was controlled at 70° C. to react for 0.5 h, and cooled to room temperature to obtain an amine inhibitor for drilling fluid with a solid content of 10%, the chemical structure of which is shown in the following formula:

[0057]

[0058] Among them, m=5.

[0059] Embodiments 4 to 6

[0060] The steps are the same as those in Example 1, and the reaction substances and their amounts are shown in Table 1:

[0061] Table 1 Reaction substances and dosage

[0062] Example Amine compounds Epichlorohydrin Solid content 4 1molN,N-dimethylpropylenediamine 0.8mol 50％ 5 1molN,N-diethylethylenediamine 0.9mol 25％ 6 1molN,N-diethylbutanediamine 0.7mol 35％

[0063] Performance Evaluation

[0064] The performance of the amine inhibitors synthesized in Examples 1 to 6 was evaluated, and the specific evaluation contents are as follows:

[0065] (1) Relative inhibition rate

[0066] 50 g (accurate to 0.01 g) of sodium carbonate and 1000 g (accurate to 0.01 g) of bentonite for drilling fluid were added to 10 L of distilled water, stirred at high speed for 2 h, and placed at room temperature for curing for 24 h to obtain a 10% fresh water base slurry; 7 portions of 400 mL of 10% fresh water base slurry were taken, and 4 g (accurate to 0.01 g) of the amine inhibitor synthesized in Examples 1 to 6 were added to 6 portions of the 7 portions of the sample, stirred at 10000 r / min for 20 min using a high-speed stirrer, then hot rolled at 150° C. for 16 h, stirred at 10000 r / min for 5 min after cooling, and the rheological parameters of the base slurry were measured using a six-speed rotation viscometer at room temperature, and the relative inhibition rate of the inhibitor was calculated. The calculation formula of the relative inhibition rate is as follows:

[0067]

[0068] Among them, (φ 100 ) 0 It is the reading of the six-speed rotary viscometer of the base slurry at 100r / min when no inhibitor is added; (φ 100 ) 1 It is the reading of a six-speed rotation viscometer at 100 r / min after adding the inhibitor.

[0069] The calculation results are shown in Table 2:

[0070] Table 2 Evaluation of the inhibition performance of amine inhibitors

[0071]

[0072]

[0073] 4 g (accurate to 0.01 g) of the amine inhibitor synthesized in Example 4 was added to 400 mL of 10% fresh water slurry, and the slurry was heated for 16 h at different temperatures. The rheological parameters of the slurry were measured using a six-speed rotary viscometer at room temperature, and the relative inhibition rate of the inhibitor was calculated. The calculation results are shown in Table 3:

[0074] Table 3 Evaluation of temperature resistance of amine inhibitors

[0075] Temperature / ℃ Relative inhibition rate, % 120 94.2 150 96.3 180 97.6 200 98.4

[0076] (2) Shale recovery rate

[0077] Take 2.0-3.8 mm shale and dry it at 105±3°C to constant weight, then cool it to room temperature; prepare 350 mL of 1% aqueous solution with the amine inhibitor synthesized in Examples 1-6, weigh 10 g shale (G 0) were placed in clean water and 1% amine inhibitor aqueous solution, rolled at 150℃ for 16h, taken out after cooling, and the core was recovered with a 0.42mm sieve, dried at 105±3℃ to constant weight, cooled to room temperature and weighed. 1 ), and the shale recovery rate is calculated using the following formula:

[0078]

[0079] The calculation results are shown in Table 4:

[0080] Table 4 Shale recovery rate of amine inhibitors

[0081]

[0082]

[0083] The amine inhibitor synthesized in Example 4 was used to prepare 350 mL of a 1% aqueous solution, and 10 g of shale (G 0 ) were placed in clean water and 1% amine inhibitor aqueous solution, respectively, and rolled at different temperatures for 16 hours. After cooling, the cores were taken out and recovered using a 0.42 mm sieve. The cores were dried at 105±3°C to constant weight, and the shale recovery rate was calculated. The calculation results are shown in Table 5:

[0084] Table 5 Evaluation of temperature resistance of amine inhibitors

[0085]

[0086] (3) Compatibility

[0087] The amine inhibitor synthesized in Example 4 was added to the prepared drilling fluid base slurry, and the effect of the synthesized inhibitor on the base slurry performance was investigated after aging at 120°C for 16 hours; the drilling fluid base slurry formula: 4wt% bentonite slurry + 2wt% MMT + 2wt% Lv-cmc + 2wt% SMP + 2wt% SMC, wherein the temperature-resistant and salt-resistant polymer fluid loss reducer MMT was produced by the Drilling Engineering Technology Research Institute of Zhongyuan Petroleum Engineering Company, the low-viscosity sodium carboxymethyl cellulose Lv-cmc was produced by Puyang Jintai Chemical Co., Ltd., the sulfonated phenolic resin SMP was produced by Shandong Juxinda Chemical Technology Co., Ltd., and the sulfonated lignite SMC was produced by Shandong Juxinda Chemical Technology Co., Ltd.; the experimental results are shown in Table 6:

[0088] Table 6 Effect of inhibitor dosage on base slurry properties

[0089]

[0090]

[0091] Performance evaluation shows that the amine inhibitor synthesized in the present invention has good inhibition and temperature resistance, can still maintain good inhibition at 200°C, can be used in high-temperature resistant drilling fluid systems, has good compatibility with drilling fluids, and has little effect on the rheology and filtration loss of drilling fluids.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An amine inhibitor for drilling fluid, It is characterized in that The drilling fluid amine inhibitor contains a compound having a structure of formula (I): In formula (I), R is C 1 ~C 10 wherein n is an integer between 1 and 10, and m is an integer between 5 and 200.

2. The amine-based inhibitor for drilling fluid according to claim 1, It is characterized in that The R is -CH 3 or -CH 2 CH 3 .

3. The amine-based inhibitor for drilling fluid according to claim 1, It is characterized in that The n is an integer between 2 and 4.

4. The amine-based inhibitor for drilling fluid according to claim 1, It is characterized in that The m is an integer between 5 and 100.

5. The amine-based inhibitor for drilling fluid according to claim 1, It is characterized in that The amine-based inhibitor for drilling fluid also contains a liquid medium; the solid content of the amine-based inhibitor for drilling fluid is 10-50wt%.

6. A method for preparing the amine-based inhibitor for drilling fluid according to any one of claims 1 to 5, It is characterized in that The following steps are involved: The amino compound of formula (i) is mixed with epichlorohydrin in a liquid medium to react to obtain an amine inhibitor for drilling fluid; In formula (i), R is C 1 ~C 10 wherein n is an integer between 1 and 10.

7. The preparation method according to claim 6, It is characterized in that The amino compound is N,N-dimethylethylenediamine, N,N-dimethylpropylenediamine, N,N-dimethylbutylenediamine, N,N-diethylethylenediamine, N,N-diethylpropylenediamine or N,N-diethylbutylenediamine.

8. The preparation method according to claim 6, It is characterized in that The molar ratio of the amino compound to epichlorohydrin is 1:(0.5-1).

9. The preparation method according to claim 6, It is characterized in that The temperature of the mixed reaction is 40-70° C.; the time of the mixed reaction is 0.5-2 h.

10. A drilling fluid, It is characterized in that The drilling fluid contains the amine inhibitor for drilling fluid according to any one of claims 1 to 5 or the amine inhibitor for drilling fluid prepared by the preparation method according to any one of claims 6 to 9.

Images