Composition for near-oil-based drilling fluid, application of composition and preparation method of near-oil-based drilling fluid base fluid

Abstract

The invention relates to the technical field of drilling fluids, and discloses a composition for a near-oil-based drilling fluid, an application of the composition, the near-oil-based drilling fluid and a preparation method of the near-oil-based drilling fluid. According to the composition for the near-oil-based drilling fluid, the composition contains silamino alkyl glycoside and cationic chitosan, the extreme pressure lubrication coefficient of the composition is 0.001 to 0.05, and the compression index of the composition is 1.3 to 5. The composition for the near-oil-based drilling fluid, provided by the invention, simultaneously contains the silamino alkyl glycoside and the cationic chitosan, and the silamino alkyl glycoside and the cationic chitosan have a relatively good synergistic effect, so that the obtained base fluid and the drilling fluid have good properties such as collapse inhibition and prevention, wall fixation and cementation, lubrication and blockage prevention, plugging and filtration loss reduction and the like, and can meet the performance requirements of preparing the near-oil-based drilling fluid.

Description

Technical Field

[0001] The invention relates to the technical field of drilling fluids, and in particular to a composition for near-oil-based drilling fluids and an application thereof, and a method for preparing a near-oil-based drilling fluid base fluid. Background Art

[0002] During oil and gas drilling, when drilling in highly active shale and mudstone-containing formations prone to collapse with high clay mineral content, conventional water-based drilling fluids cannot effectively inhibit the hydration, expansion and dispersion of highly active shale and other formations prone to collapse; although strong inhibition water-based drilling fluids have better inhibition and anti-collapse effects, and are low in cost and environmentally friendly, their performance has not yet reached the same level as oil-based drilling fluids; when drilling in highly active shale and other formations prone to collapse, there are still many shortcomings when using oil-based drilling fluids for drilling, specifically manifested in high preparation costs, interference with logging operations, serious losses during well leakage, and high pressure of post-processing of drill cuttings. These shortcomings limit the larger-scale application of oil-based drilling fluids. Therefore, under this situation, seeking a near-oil-based drilling fluid with a mechanism similar to that of oil-based drilling fluids, equivalent performance to that of oil-based drilling fluids, and environmentally friendly has become an urgent need for field technology. Near-oil-based drilling fluid is a green, safe and efficient water-based drilling fluid with performance comparable to that of oil-based drilling fluid. It belongs to the category of water-based drilling fluid, not an oil-based drilling fluid.

[0003] For near-oil-based drilling fluids, the most critical thing is the base fluid used to prepare near-oil-based drilling fluids. The base fluid used to prepare near-oil-based drilling fluids is required to have good performance in inhibiting collapse, consolidating walls, lubricating and preventing sticking, plugging and reducing filtration, and is green and environmentally friendly, and can meet the performance requirements of preparing near-oil-based drilling fluids. The research and development of base fluid products used to prepare near-oil-based drilling fluids will play a good role in promoting the research and application of near-oil-based drilling fluids, achieving green, safe, and efficient drilling of highly active shale and shale-containing formations prone to collapse, and achieving the technical goal of "water replacing oil". Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art and to provide a base fluid for preparing near-oil-based drilling fluid and a preparation method thereof. The base fluid for preparing near-oil-based drilling fluid provided by the present invention has good properties of inhibiting collapse, wall solidification, lubrication and anti-sticking, plugging and reducing filtration loss, is green and environmentally friendly, and can meet the performance requirements for preparing near-oil-based drilling fluid.

[0005] To achieve the above object, according to a first aspect of the present invention, a composition for near-oil-based drilling fluid is provided, the composition contains silanol amino alkyl glycoside and cationic chitosan, and the extreme pressure lubrication coefficient of the composition is 0.001-0.05 and the compression index is 1.3-5.

[0006] According to a second aspect of the present invention, the present invention provides use of the above composition in near-oil-based drilling fluid.

[0007] According to a third aspect of the present invention, the present invention provides a near-oil-based drilling fluid composition.

[0008] According to a fourth aspect of the present invention, the present invention provides a method for preparing a near-oil-based drilling fluid base fluid, the method comprising:

[0009] In parts by mass, 0-15 parts, preferably 3-12 parts of multi-branched polyetheramine, 0-45 parts, preferably 10-40 parts of aminocyclodextrin, 1-10 parts, preferably 3-7 parts of cationic chitosan, 40-60 parts, preferably 42-58 parts of silanylamino alkyl glycoside, and 0-30 parts, preferably 18-24 parts of sulfonylamino glyceryl glycoside are stirred and mixed uniformly at 60-85° C. under the protection of inert gas.

[0010] The composition for near-oil-based drilling fluid provided by the present invention contains both silanol amino alkyl glycoside and cationic chitosan, which have good synergistic effects, so that the obtained base fluid and drilling fluid have good performances such as anti-collapse inhibition, wall solidification, lubrication and anti-sticking, plugging and reducing filtration loss, etc., which can meet the performance requirements of preparing near-oil-based drilling fluid. According to a preferred embodiment of the present invention, when the base fluid contains a certain ratio of multi-branched polyetheramine, aminocyclodextrin, cationic chitosan, silanol amino alkyl glycoside, and sulfonylamino glyceryl glycoside, the performance of the obtained base fluid and drilling fluid in inhibiting anti-collapse, wall solidification, lubrication and anti-sticking, plugging and reducing filtration loss is further improved. Moreover, the above-mentioned base fluid is green and environmentally friendly, and has strong compatibility, which can meet the performance requirements of preparing near-oil-based drilling fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figures 1 to 5 They are the infrared spectra of multi-branched polyetheramine, aminocyclodextrin, cationic chitosan, silanylaminoalkyl glycoside and sulfonylglycerol glycoside respectively.

[0012] Figure 6 This is a scanning electron microscope photo of the medium-pressure filter cake of 4wt% sodium bentonite-based slurry.

[0013] Figure 7 Scanning electron microscope photograph of medium pressure filter cake after adding 2% sample of Example 1 to 4wt% sodium bentonite-based slurry. DETAILED DESCRIPTION

[0014] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0015] The composition for near-oil-based drilling fluid provided by the present invention contains silanol amino alkyl glycoside and cationic chitosan, and the extreme pressure lubrication coefficient of the composition is 0.001-0.05, and the compression index is 1.3-5. Preferably, the extreme pressure lubrication coefficient of the composition is 0.005-0.025, and the compression index is 1.5-3.

[0016] The near-oil-based drilling fluid composition provided by the present invention contains both silanol amino alkyl glycoside and cationic chitosan, has a low extreme pressure lubrication coefficient, good lubrication and anti-sticking properties, good plugging and filtration loss reduction properties, and a compression index in the range of 1.3-5, preferably 1.5-3, so it has good compression resistance.

[0017] The infrared spectrum can be used to prove that the composition contains silanol amino alkyl glycoside and cationic chitosan. For example, there is a 2830-2950cm -1 The stretching vibration peak of the CH bond in the methyl and methylene groups is 3380 cm -1 Nearby is the stretching vibration peak of the OH bond, 1164 cm -1 Nearby is the stretching vibration peak of COC, which can confirm the presence of glycoside structure; 1419cm -1 Nearby is the absorption peak of CN bond, 1196cm -1 Nearby is the bending vibration peak of the CN bond, which can determine the structure containing amine groups; 1689cm -1 Nearby, 1280cm -1 Nearby is the characteristic peak of amide group; 1093cm -1 It is the characteristic peak of Si-O. It indicates that the amino group, amide group and siloxane group have been introduced into the molecular structure of glycoside, that is, the composition contains silanol amino alkyl glycoside. -1 Nearby is the chitosan NH bending vibration absorption peak, 1214 cm -1 The COC stretching vibration absorption peak is nearby, indicating that the modified chitosan has introduced ether bonds through condensation reaction, 1405cm -1 The vicinity is the CN stretching vibration absorption peak, indicating that the modified chitosan has introduced a quaternary ammonium group. In the present invention, the vicinity refers to the instrument and operation error acceptable to those skilled in the art, for example, ±10 cm -1 .

[0018] In the present invention, the compressive index refers to the ratio of the compressive strength of the core before and after immersion. Compression index = P1 / P0. The core column is placed on a compressive strength meter, and the load is increased at a rate of 0.5-0.8 MPa per second until the pressure at which the core column is destroyed is the compressive strength, wherein the compressive strength of the original core without immersion is recorded as P0, and the compressive strength of the core column measured after immersion in a sample of a near-oil-based drilling fluid composition with a mass concentration of 2.0% at 210°C for 16 hours is recorded as P1.

[0019] The extreme pressure lubrication coefficient calculation formula is:

[0020]

[0021] In the above formula: K is the extreme pressure lubrication coefficient; X and Y are obtained by the following test methods: immerse the slider in the extreme pressure lubrication instrument into a 2.0% base fluid sample to be tested for preparing near-oil base drilling fluid, adjust the torque wrench value to 16.95 N / m, and the value displayed on the instrument when the instrument is operated for 5 minutes is X; immerse the slider in the instrument into clean water, adjust the torque wrench value to 16.95 N / m, and the instrument is operated for 5 minutes, and the value displayed on the instrument when the slider is immersed in clean water is Y.

[0022] In the present invention, the silanol amino alkyl glycoside refers to a product in which the hydrogen in one or more hydroxyl groups on the alkyl glycoside structure is replaced by a group containing an amine group (primary amine group, secondary amine group, tertiary amine group) and a siloxane (trialkoxysilane) group.

[0023] According to a preferred embodiment of the present invention, in the present invention, the silanol amino alkyl glycoside has a structure shown in the following formula I:

[0024]

[0025] In formula I, R1 is a C1-C14 alkyl group, m is 1-16, and relative to the total amount of silanol amino alkyl glycoside, the content of X is 25-60 mass %, preferably 35-55 mass %, the content of Y is 30-55 mass %, preferably 40-50 mass %, and the content of Z is 0.2-60 mass %, preferably 0.2-55 mass %;

[0026] X, Y, and Z are each at least one of H, an unsaturated amide residue, an unsaturated siloxane residue, a polyether group, and a polyene polyamine residue, and X, Y, and Z are different;

[0027] Preferably, X, Y, and Z are each at least one of H, a group represented by the following formula I-1), a group represented by the following formula I-2), and a group represented by the following formula I-3, and X, Y, and Z are different;

[0028] Preferably, Y comprises an unsaturated amide residue and an unsaturated siloxane residue;

[0029]

[0030] In formula I-1), R2 is a C1-C3 alkyl group, n is 1-2, and o is 0-4;

[0031]

[0032] In formula I-2), R3 is H or C1-C4 alkyl, and p is 1-30;

[0033] In formula I-3), R4 is a C1-C4 alkyl group, and q is 1-20;

[0034] Preferably, Y includes a group represented by the above formula I-2) and a group represented by the above formula I-3).

[0035] In the present invention, the silanol amino alkyl glycoside can be prepared by referring to the method disclosed in CN111320657A, and specifically, the method may include the following steps: 1) reacting an alkyl glycoside with an epoxy halogenated (such as chlorinated) alkane compound under the action of an acidic catalyst to obtain a haloalcohol alkyl glycoside; 2) reacting the haloalcohol alkyl glycoside with an organic amine to obtain an amino alkyl glycoside; 3) reacting the amino alkyl glycoside with an acrylamide compound and a vinyltrialkoxysilane under the action of an initiator to obtain a silanol amino alkyl glycoside.

[0036] Wherein, the alkyl glycoside can be one or more of methyl glycoside, ethyl glycoside, propyl glycoside, hexyl glycoside, octyl glycoside, decyl glycoside, dodecyl glycoside and tetradecyl glycoside. That is, corresponding to the above formula I, R1 can be a C1-C14 alkyl group such as methyl, ethyl, propyl, hexyl, octyl, decyl, dodecyl and tetradecyl.

[0037] The epoxyhalogenated (such as chloro) alkane compound may be, for example, one or more of epichlorohydrin, epichlorobutane, and epichloropentane.

[0038] The acrylamide compound may be, for example, acrylamide or methacrylamide.

[0039] The vinyltrialkoxysilane may be, for example, one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, and vinyltributoxysilane.

[0040] The acidic catalyst may be, for example, one or more of hydrofluoric acid, hydrochloric acid, sulfuric acid, phosphoric acid, tartaric acid, oxalic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and aminosulfonic acid.

[0041] The initiator may be a redox initiator or an azo initiator, for example, may be selected from ammonium persulfate, potassium persulfate, cerium ammonium nitrate, azobisisobutyronitrile, dimethyl azobisisobutyrate, and azobisisobutylamidine hydrochloride.

[0042] The infrared spectrum of the obtained product can confirm that the obtained polymer is the target polymer. -1 The stretching vibration peak of the CH bond in the methyl and methylene groups is 3380 cm-1 Nearby is the stretching vibration peak of OH bond, 1164cm -1 Nearby is the stretching vibration peak of COC, which can confirm the presence of glycoside structure; 1419cm -1 Nearby is the absorption peak of CN bond, 1196cm -1 The bending vibration peak of the CN bond can be used to determine the structure containing an amine group; 1689cm -1 Nearby, 1280cm -1 Nearby is the characteristic peak of amide group; 1093cm -1 Nearby is the characteristic peak of Si-O, which indicates that the amino group, amide group and siloxane group have been introduced into the molecular structure of glycoside.

[0043] In the present invention, the cationic chitosan refers to chitosan in which one or more hydroxyl groups are replaced by residues containing cationic groups, and the cationic groups are preferably quaternary ammonium cations, and the anions that match the quaternary ammonium cations can be chloride ions, bromide ions, iodide ions, and nitrate ions. According to a preferred embodiment of the present invention, in the present invention, the cationic chitosan has a structure shown in the following formula II

[0044]

[0045] In formula II, R is an alkyl group having 1 to 3 carbon atoms, m is 1200 to 3100, and n is 1 to 2.

[0046] In the present invention, cationic chitosan can be prepared by referring to the method disclosed in CN106432537A. Specifically, the method can include the following steps: 1) reacting a mixture containing chitosan, a cosolvent such as a urea compound, an alkaline compound and water with an epoxyhalogenated (such as chloro) alkane compound to obtain an intermediate product; 2) reacting the intermediate product with an alkaline compound and a tertiary amine hydrochloride to obtain cationic chitosan.

[0047] The epoxyhalogenated (such as chloro) alkane compound may be one or more of epichlorohydrin, 1,2-epoxychlorobutane, and epichloropentane.

[0048] The alkaline compound may be, for example, sodium hydroxide and / or potassium hydroxide.

[0049] The tertiary amine hydrochloride may be, for example, one or more of trimethylamine hydrochloride, triethylamine hydrochloride, and tripropylamine hydrochloride.

[0050] The urea compound may be, for example, one or more of urea, thiourea, and urea phosphate.

[0051] The infrared spectrum of the obtained product can confirm that the obtained polymer is the target polymer.-1 Nearby is the chitosan NH bending vibration absorption peak, 1214 cm -1 The COC stretching vibration absorption peak is nearby, indicating that the modified chitosan has introduced ether bonds through condensation reaction, 1405cm -1 Nearby is the CN stretching vibration absorption peak, indicating that quaternary ammonium groups have been introduced into the modified chitosan.

[0052] According to a preferred embodiment of the present invention, the composition further contains multi-branched polyetheramine and sulfonylaminoglyceryl glycoside. The composition of this preferred embodiment can further improve the inhibition and lubricity of the drilling fluid.

[0053] Preferably, based on the total amount of the composition, the content of the multi-branched polyetheramine is 1-15% by mass, preferably 3-12% by mass, the content of the silanylaminoalkyl glycoside is 40-90% by mass, preferably 40-58% by mass, the content of the sulfonylaminoglyceryl glycoside is 5-30% by mass, preferably 15-25% by mass, and the content of the cationic chitosan is 1-11% by mass, preferably 3-7% by mass.

[0054] In the present invention, the multi-branched polyetheramine refers to a molecule containing multiple amine groups (primary amine groups, secondary amine groups, tertiary amine groups), and preferably some or all of the multiple amine groups (primary amine groups, secondary amine groups, tertiary amine groups) are distributed in a comb-like shape. Preferably, at least two hydroxyl groups in glycerol are replaced by amine-containing groups such as amine-containing segments with 2 to 30 carbon atoms. Preferably, the multi-branched polyetheramine has a structure shown in Formula III,

[0055]

[0056] Preferably, in formula III, m is 1-16, n is 1-2, and o is 0-4.

[0057] The multi-branched polyetheramine can be prepared by referring to the method disclosed in CN106432708A. For example, glycerol, a glycol compound, water and an acidic catalyst are reacted (preferably under stirring conditions) to obtain an intermediate product, wherein the glycol compound includes ethylene glycol or polyethylene glycol; the intermediate product is reacted with a chloroepoxide, an alkaline compound and an organic amine to obtain a multi-branched polyetheramine; the chloroepoxide includes epichlorohydrin or 1,2-epoxychlorobutane, and the organic amine includes ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine. Preferably, the temperature of the reaction of glycerol, glycol compound, water and acidic catalyst is 90°C-140°C, preferably 100°C-120°C; the time is 2 hours-4 hours, preferably 2.5 hours-3.5 hours. In an embodiment of the present invention, glycerol, glycol compound, water and acidic catalyst can be reacted under stirring conditions. After obtaining the intermediate product, the present invention reacts the intermediate product with chloroepoxide, alkaline compound and organic amine to obtain a multi-branched polyetheramine. In an embodiment of the present invention, the temperature of the reaction of the intermediate product with chloroepoxide, alkaline compound and organic amine is 40°C-60°C, preferably 45°C-55°C; the reaction time is 0.5 hour-2 hours, preferably 1 hour-1.5 hours.

[0058] Preferably, the number average molecular weight of the polyethylene glycol is 400-800, preferably 500-700, and further preferably 550-650.

[0059] Preferably, the acidic catalyst may be hydrochloric acid, sulfuric acid, phosphoric acid, tartaric acid, oxalic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, aminosulfonic acid or phosphotungstic acid.

[0060] Preferably, the chlorinated epoxide is epichlorohydrin or 1,2-epoxychlorobutane.

[0061] Preferably, the alkaline compound is one or more of sodium hydroxide, potassium hydroxide and barium hydroxide.

[0062] Preferably, the organic amine includes ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine.

[0063] Preferably, the mass ratio of the glycerol, glycol compound, water, acidic catalyst, chloroepoxide, alkaline compound and organic amine is 10:(8-14):(30-60):(0.8-1.5):(5-15):(0.8-1.2):(10-20), further preferably 10:(9-12):(40-50):(1-1.4):(8-12):(0.9-1.1):(12-18), and even more preferably 10:(10-11):(42-48):(1.1-1.3):(10-11):1:(14-16).

[0064] In the present invention, the sulfonylaminoglyceryl glycoside refers to one or more hydroxyl groups of glyceryl glycoside replaced by polyetheramine groups and sulfonated castor oil residues, wherein the polyetheramine group refers to a group containing an amine group (primary amine, secondary amine or tertiary amine) connected in the middle or at the end of a polyether group. The sulfonated castor oil residue refers to a group corresponding to the esterification reaction between sulfonated castor oil and the hydroxyl group of glyceryl glycoside. Preferably, the sulfonylaminoglyceryl glycoside has a structure shown in the following formula IV

[0065]

[0066] In formula IV, m is 1-3, and the content of X is 30-70 mass %, preferably 35-55 mass %, and the content of Y is 20-50 mass %, preferably 25-40 mass % relative to the total amount of sulfonylaminoglyceryl glycoside;

[0067] X and Y are each a group represented by the following formula IV-1) or a group represented by the following formula IV-2), and X and Y are different;

[0068]

[0069] In formula IV-1), R1 and R2 are each independently selected from an alkyl group having 1 to 3 carbon atoms, n is 1 to 10, o is 1 to 10, and p is 0 to 4.

[0070] Sulfonamidoglyceryl glycoside can be prepared by referring to the method disclosed in CN111320659A.

[0071] According to a preferred embodiment of the present invention, the composition further contains aminocyclodextrin, preferably, based on the total amount of the composition, the content of aminocyclodextrin is 2-45% by mass, more preferably 10-40% by mass. The composition of this preferred embodiment can further improve the inhibition, fluid loss reduction and lubricity of the drilling fluid.

[0072] In the present invention, the aminocyclodextrin refers to one or more amino groups on the cyclodextrin substituted with amine groups, preferably substituted with polyene polyamine groups such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine. Preferably, the aminocyclodextrin has a structure shown in the following formula V

[0073]

[0074] In formula V, based on the total amount of aminocyclodextrin, the content of R is 30-70 mass %, preferably 40-55 mass %, and R has the structure shown in the following structural formula i

[0075]

[0076] In formula i, m is 1-2, and n is 0-4.

[0077] Aminocyclodextrin can be prepared by referring to the method disclosed in CN106432550A.

[0078] The invention also provides application of the composition in near-oil-based drilling fluid.

[0079] The present invention also provides near-oil-based drilling fluid containing the composition.

[0080] Preferably, based on the total amount of the near-oil-based drilling fluid, the content of the composition is 20-60% by mass.

[0081] The present invention also provides a method for preparing a near-oil-based drilling fluid base fluid, the method comprising:

[0082] In parts by mass, 0-15 parts, preferably 3-12 parts of multi-branched polyetheramine, 0-45 parts, preferably 10-40 parts of aminocyclodextrin, 1-10 parts, preferably 3-7 parts of cationic chitosan, 40-60 parts, preferably 42-58 parts of silanylamino alkyl glycoside, and 0-30 parts, preferably 18-24 parts of sulfonylamino glyceryl glycoside are stirred and mixed uniformly at 60-85° C. under the protection of inert gas, and the preferred time is 2-4 hours.

[0083] Preferably, the inert gas is nitrogen and / or helium.

[0084] In the following examples, the multi-branched polyetheramine was prepared by referring to the method disclosed in CN106432708A, the aminocyclodextrin was prepared by referring to the method disclosed in CN106432550A, the cationic chitosan was prepared by referring to the method disclosed in CN106432537A, the silanolamino alkyl glycoside was prepared by referring to the method disclosed in CN111320657A, and the sulfonylamino glyceryl glycoside was prepared by referring to the method disclosed in CN111320659A. The infrared spectra of the polymers used in Example 1 are as follows: Figure 1-5 As shown. Figure 1 As shown, 1151cm -1 is the stretching vibration peak of COC, 1050~1100cm -1 The peak of stretching vibration of CO bond in hydroxyl group can be confirmed to contain polyether structure; 1419cm -1 is the absorption peak of CN bond, 1196cm -1 is the bending vibration peak of the CN bond, 3380cm -1 The absorption peak of NH can be used to determine the structure containing amines. Based on the above results, the molecular structure of the multi-branched polyetheramine product contains characteristic structures such as hydroxyl, ether bond, CN bond, and amine group.

[0085] The infrared spectrum of aminocyclodextrin is as follows Figure 2 As shown, 3357cm -1 Shows stretching vibrations of -OH and primary amine -NH, 2930 cm -1 The antisymmetric stretching vibration absorption peak of -CH2 is 1458cm -1 The absorption peaks are the deformation vibration of -CH2 and the antisymmetric deformation vibration of -CH3, while 1154cm -1 The CO stretching vibration absorption peak of β-CD and the polymer cavity and the COC stretching vibration absorption peak are 707 cm -1 It shows the in-plane rocking vibration absorption peak of -CH2.

[0086] The infrared spectrum of cationic chitosan is as follows Figure 3 As shown, at 1602cm -1 The chitosan NH bending vibration absorption peak is 1214 cm -1 The COC stretching vibration absorption peak is at 1405cm -1 The CN stretching vibration absorption peak is at , indicating that quaternary ammonium groups are introduced into the modified chitosan.

[0087] The infrared spectrum of silanol amino alkyl glycoside is as follows Figure 4 As shown, 2830~2950cm -1 The stretching vibration peak of the CH bond in the methyl and methylene groups is 3380 cm -1 is the stretching vibration peak of OH bond, 1164cm -1 The stretching vibration peak of COC indicates the presence of a glycoside structure; 1419 cm -1 is the absorption peak of CN bond, 1196cm -1 The bending vibration peak of the CN bond can be used to determine the structure containing an amine group; 1689cm -1 、1280cm -1 is the characteristic peak of amide group; 1093cm-1 It is the characteristic peak of Si-O, which indicates that the amino group, amide group and siloxane group have been introduced into the molecular structure of glycoside.

[0088] The infrared spectrum of sulfaminylglycerol glycoside is as follows Figure 5 As shown, 3380cm -1 The stretching vibration peak of the OH bond is 2830-2950cm -1 1151cm is the stretching vibration peak of the CH bond in the methyl and methylene groups, which can be used to determine the presence of glycoside structure; -1 is the stretching vibration peak of COC, 1050~1100cm -1 The peak of the stretching vibration of the CO bond in the hydroxyl group can be used to determine the presence of a glyceryl structure; 1419 cm -1 is the absorption peak of CN bond, 1196cm -1 It is the bending vibration peak of the CN bond, which can determine the structure containing amine; wave number 1170cm -1 , 1000cm -1 It is the characteristic peak of sulfonic acid group, which indicates that glyceryl group, amino group and sulfonic acid group have been introduced into the molecular structure of glycoside.

[0089] Example 1

[0090] 3 g of multi-branched polyetheramine (prepared according to the method of Example 1 of CN106432708A), 10 g of aminocyclodextrin (prepared according to the method of Example 1 of CN106432550A), 3 g of cationic chitosan (prepared according to the method of Example 1 of CN106432537A), 42 g of silanylaminoalkyl glycoside (prepared according to the method of Example 1 of CN111320657A), and 18 g of sulfonylaminoglyceryl glycoside (prepared according to the method of Example 1 of CN111320659A) were mixed uniformly, and stirred at 60°C for 2 h under nitrogen protection to obtain a base fluid for preparing near-oil-based drilling fluid.

[0091] Example 2

[0092] 7 g of multi-branched polyetheramine (prepared according to the method of Example 2 of CN106432708A), 20 g of aminocyclodextrin (prepared according to the method of Example 2 of CN106432550A), 5 g of cationic chitosan (prepared according to the method of Example 2 of CN106432537A), 48 g of silanylaminoalkyl glycoside (prepared according to the method of Example 1 of CN111320657A), and 20 g of sulfonylaminoglyceryl glycoside (prepared according to the method of Example 2 of CN111320659A) were mixed uniformly, and stirred at 70°C for 3 h under helium protection to obtain a base liquid for preparing near-oil-based drilling fluid.

[0093] Example 3

[0094] 9 g of multi-branched polyetheramine (prepared according to the method of Example 3 of CN106432708A), 30 g of aminocyclodextrin (prepared according to the method of Example 3 of CN106432550A), 6 g of cationic chitosan (prepared according to the method of Example 3 of CN106432537A), 54 g of silanylaminoalkyl glycoside (prepared according to the method of Example 1 of CN111320657A), and 22 g of sulfonylaminoglyceryl glycoside (prepared according to the method of Example 3 of CN111320659A) were mixed uniformly, and stirred at 80°C for 4 h under nitrogen protection to obtain a base liquid for preparing near-oil-based drilling fluid.

[0095] Example 4

[0096] 12g of multi-branched polyetheramine (prepared according to the method of Example 4 of CN106432708A), 40g of aminocyclodextrin (prepared according to the method of Example 4 of CN106432550A), 7g of cationic chitosan (prepared according to the method of Example 4 of CN106432537A), 58g of silanylaminoalkyl glycoside (prepared according to the method of Example 1 of CN111320657A), and 24g of sulfonylaminoglyceryl glycoside (prepared according to the method of Example 4 of CN111320659A) were mixed uniformly, and stirred at 85°C for 4h under nitrogen protection to obtain a base liquid for preparing near-oil-based drilling fluid.

[0097] Example 5

[0098] The base fluid of the near-oil-based drilling fluid was prepared according to the method of Example 4, except that the multi-branched polyetheramine, aminocyclodextrin and sulfonylaminoglycerol glycoside were not added, and the proportions of other substances remained unchanged, thereby obtaining the base fluid for preparing the near-oil-based drilling fluid.

[0099] Example 6

[0100] The base fluid of the near-oil-based drilling fluid was prepared according to the method of Example 4, except that aminocyclodextrin and sulfonylaminoglyceryl glycoside were not added, and the proportions of other substances remained unchanged, thereby obtaining the base fluid for preparing the near-oil-based drilling fluid.

[0101] Example 7

[0102] The base fluid of the near-oil-based drilling fluid was prepared according to the method of Example 4, except that the multi-branched polyetheramine and aminocyclodextrin were not added, and the proportions of other substances remained unchanged, thereby obtaining the base fluid for preparing the near-oil-based drilling fluid.

[0103] Comparative Example 1

[0104] The base fluid of near-oil-based drilling fluid was prepared according to the method of Example 4, except that the above materials were stirred at room temperature for 4 hours in an air environment to obtain a comparative example sample.

[0105] Comparative Example 2

[0106] The base liquid of the near-oil-based drilling fluid was prepared according to the method of Example 4, except that cationic chitosan was not added, and the ratios of other substances remained unchanged. The above materials were stirred at room temperature in an air environment for 4 hours to obtain the base liquid for preparing the near-oil-based drilling fluid.

[0107] Comparative Example 3

[0108] The base liquid of the near-oil-based drilling fluid was prepared according to the method of Example 4, except that silanol alkyl glycoside was not added, and the proportions of other substances remained unchanged. The above materials were stirred at room temperature in an air environment for 4 hours to obtain the base liquid for preparing the near-oil-based drilling fluid.

[0109] Performance Testing

[0110] The base fluid prepared in the embodiment of the present invention for preparing near-oil-based drilling fluid was tested for its performance in inhibiting collapse, consolidating walls, lubricating and preventing sticking, plugging and reducing filtration loss, and biological toxicity.

[0111] 1) Inhibitory

[0112] ① Shale recovery rate

[0113] The near-oil-based base fluid provided by the present invention is prepared into a near-oil-based base fluid aqueous solution with a mass concentration of 2%, and rolled at a high temperature of 210° C. for 16 hours. The shale primary recovery rate and shale relative recovery rate are tested according to the following method:

[0114] The above-mentioned 2% near-oil-based base liquid aqueous solution was stirred at a high speed of 7000 rpm for 5 minutes, and then poured into an aging tank for use; 2.0mm-5.0mm rock chips were taken and dried at 103°C for 4 hours, and cooled to room temperature; G0g of rock chips were weighed and put into an aging tank and rolled with the above-mentioned 2% near-oil-based base liquid aqueous solution at 210°C for 16 hours, and then taken out after cooling, and the rock chips were recovered with a 0.42mm sieve, dried at 103°C for 4 hours, cooled to room temperature, and the mass of the recovered rock chips was weighed and recorded as G1; then the weighed recovered rock chips were put into clean water and rolled at 210°C for 16 hours, and then taken out after cooling, and the rock chips were recovered with a 0.42mm sieve, dried at 103°C for 4 hours, cooled to room temperature, and the mass of the recovered rock chips was weighed and recorded as G2; the primary recovery rate of shale, the secondary recovery rate of shale and the relative recovery rate of shale were calculated according to the following formula:

[0115] Shale primary recovery rate = G1 / G0×100%;

[0116] Secondary recovery rate of shale = G2 / G0×100%;

[0117] Shale relative recovery rate = shale secondary recovery rate / shale primary recovery rate × 100%;

[0118] ②Relative inhibition rate

[0119] The relative inhibition rate is expressed as follows: 350 mL of distilled water is added with 1.75 g of sodium carbonate, and after dissolving, 35 g of calcium bentonite is added and stirred at high speed for 20 minutes to obtain calcium soil-based slurry. After aging at 210°C for 16 hours, the mixture was cooled and taken out, stirred at high speed for 5 minutes, and the 100r / min reading of the drilling fluid was measured by a six-speed rotary viscometer as φ1 (172); 350mL of distilled water was added, 1.75g ​​of sodium carbonate and 2.0% of the base fluid sample for preparing near-oil-based drilling fluid (the mass of the base fluid sample was 2.0% of the mass of distilled water), and after fully dissolved, 35g of calcium bentonite was added, stirred at high speed for 20 minutes, aged at 210°C for 16 hours, cooled and taken out, stirred at high speed for 5 minutes, and the 100r / min reading of the drilling fluid was measured by a six-speed rotary viscometer as φ2. The relative inhibition rate of the base fluid sample for preparing near-oil-based drilling fluid on calcium-soil-based slurry was calculated according to the following formula:

[0120]

[0121] 2) Compression resistance

[0122] The compressive resistance is expressed by compressive strength and compressive coefficient. The core column was soaked with the embodiment of the present invention and the comparative example sample with a mass concentration of 2.0%, and soaked at 210°C for 16 hours, and the compressive strength P1 of the core column was tested. The detection method of the compressive strength of the soaked core column is as follows: the soaked core column is placed on a compressive strength meter, and the load is increased at a rate of 0.5-0.8MPa per second to the pressure when the column is destroyed, which is the compressive strength P1. The compressive strength of the original core without soaking is recorded as P0, which is 6.9MPa. Compression index = P1 / P0.

[0123] 3) Lubricity

[0124] The test method is as follows: immerse the slider in the extreme pressure lubrication instrument into the 2.0% base fluid sample used to prepare the near-oil base drilling fluid to be tested, adjust the torque wrench value to 16.95N / m, run the instrument for 5 minutes, and read the value displayed on the instrument when the slider is immersed in the 2.0% base fluid sample used to prepare the near-oil base drilling fluid as X; immerse the slider in the instrument in clean water, adjust the torque wrench value to 16.95N / m, run the instrument for 5 minutes, and read the value displayed on the instrument when the slider is immersed in clean water as Y. The extreme pressure lubrication coefficient calculation formula is:

[0125]

[0126] In the above formula: K is the extreme pressure lubrication coefficient; X is the value displayed on the instrument when the slider is immersed in a 2.0% base fluid sample used to prepare near-oil base drilling fluid; Y is the value displayed on the extreme pressure lubrication instrument when the slider is immersed in clean water, which is 41.

[0127] 4) Fluid loss reduction

[0128] According to the standard of GB / T 16783.1-2014 "Field Test of Drilling Fluids in Petroleum and Natural Gas Industry Part 1: Water-Based Drilling Fluids", the filtration loss of 4% sodium bentonite-based slurry before and after adding 2% of the embodiment and comparative sample was tested. The filtration loss of 4% sodium bentonite-based slurry before addition was 48 mL, and the test conditions were: high temperature aging at 210°C for 16 hours.

[0129] The preparation method of 4% sodium bentonite-based slurry is as follows: add 2.0 g of anhydrous sodium carbonate and 40 g of sodium bentonite for drilling fluid test into 1 L of water, stir for 20 minutes, and then cure at room temperature for 24 hours to prepare the slurry.

[0130] The scanning electron microscope photos of the medium pressure filter cake before and after adding 2% of the sample of Example 1 to the 4wt% sodium bentonite base slurry are as follows: Figure 6 and Figure 7 As shown. Figure 6 and Figure 7 It can be seen that the medium-pressure filter cake prepared by filter press with 4wt% sodium bentonite slurry has a rough and uneven surface and a large porosity; while the medium-pressure filter cake prepared by filter press with 4wt% sodium bentonite slurry added with 2% sample of Example 1 has a smooth surface, forming a dense adsorption film without voids, which can effectively prevent the filtrate from invading the formation and ensure the wellbore stabilization effect of the formation. At the same time, the presence of the adsorption film can effectively reduce the friction between the drill bit and the wellbore rock, showing a good lubrication and anti-sticking effect.

[0131] 5) Biological toxicity

[0132] Biotoxicity EC 50 The test method of the value is as follows: add the samples of the embodiment and comparative example provided by the present invention into a sodium chloride solution with a mass concentration of 3%, and prepare 0 mg.dm -3 、5000mg.dm -3 、10000mg.dm -3 、25000mg.dm -3 、50000mg.dm -3 、100000mg.dm -310 mL of the sample solution to be tested was added to each sample solution and allowed to stand for 60 min. 10 mg of luminescent bacteria T3 powder was added to the sample solution to be tested and mixed thoroughly. Then, a 3% sodium chloride solution was used as a comparison to determine the biological toxicity EC of the luminescent bacteria after contacting with the sample solution for 15 min. 50 Value. 50 When the value is ≥30000 mg / L, it is considered to be non-biologically toxic and is the allowable emission standard.

[0133] The above test results are shown in Table 1.

[0134] Table 1 Performance of Examples and Comparative Examples

[0135]

[0136]

[0137] As shown in Table 1, the above-mentioned cationic chitosan, silanol alkyl glycoside, and optional multi-branched polyetheramine, amino cyclodextrin, and sulfonylamino glyceryl glycoside are uniformly mixed, stirred for a certain time at a certain temperature under the protection of inert gas, and the synergistic effect is exerted. The base fluid for preparing near-oil-based drilling fluid, after high-temperature aging at 210°C for 16 hours, has a shale primary recovery rate of ≥96.95% for 2% of the example sample; the relative inhibition rate of 2% of the example sample on calcium soil-based slurry is ≥97.97%, and the relative inhibition rate of 2% of the comparative sample on calcium soil-based slurry is ≥88.95%. It is explained that the base fluid for preparing near-oil-based drilling fluid prepared in the embodiment of the present invention exhibits outstanding performances such as inhibition of collapse, wall consolidation, lubrication and anti-stuck, plugging and reducing filtration loss, is green and environmentally friendly, and can meet the performance requirements for preparing near-oil-based drilling fluid.

[0138] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition for near-oil-based drilling fluid, comprising silanol amino alkyl glycoside and cationic chitosan, and the composition has an extreme pressure lubrication coefficient of 0.001-0.05 and a compression index of 1.3-5.

2. The composition according to claim 1, wherein The extreme pressure lubrication coefficient of the composition is 0.005-0.025 and the compression resistance index is 1.5-3.

3. The composition according to claim 1 or 2, wherein The composition also contains a multi-branched polyetheramine and a sulfonamidoglyceryl glycoside.

4. The composition according to claim 3, wherein Based on the total amount of the composition, the content of the multi-branched polyetheramine is 1-15% by mass, preferably 3-12% by mass, the content of the silanylaminoalkyl glycoside is 40-90% by mass, preferably 40-58% by mass, the content of the sulfonylaminoglyceryl glycoside is 5-30% by mass, preferably 15-25% by mass, and the content of the cationic chitosan is 1-11% by mass, preferably 3-7% by mass.

5. The composition according to claim 3 or 4, wherein The silanol amino alkyl glycoside has a structure shown in the following formula I: In formula I, R1 is a C1-C14 alkyl group, m is 1-16, and relative to the total amount of silanol amino alkyl glycoside, the content of X is 25-60 mass %, preferably 35-55 mass %, the content of Y is 30-55 mass %, preferably 40-50 mass %, and the content of Z is 0.2-60 mass %, preferably 0.2-55 mass %; X, Y, and Z are each at least one of H, an unsaturated amide residue, an unsaturated siloxane residue, a polyether group, and a polyene polyamine residue, and X, Y, and Z are different; Preferably, X, Y, and Z are each at least one of H, a group represented by the following formula I-1), a group represented by the following formula I-2), and a group represented by the following formula I-3, and X, Y, and Z are different; Preferably, Y comprises an unsaturated amide residue and an unsaturated siloxane residue; In formula I-1), R2 is a C1-C3 alkyl group, n is 1-2, and o is 0-4; In formula I-2), R3 is H or C1-C4 alkyl, and p is 1-30; In formula I-3), R4 is a C1-C4 alkyl group, and q is 1-20; Preferably, Y contains a group represented by the above formula I-2) and a group represented by the above formula I-3); The cationic chitosan has a structure shown in the following formula II; In formula II, R is an alkyl group having 1 to 3 carbon atoms, m is 1200 to 3100, and n is 1 to 2.

6. The composition according to claim 3, 4 or 5, wherein The multi-branched polyetheramine has a structure shown in Formula III, In formula III, m is 1-16, n is 1-2, and o is 0-4.

7. The composition according to any one of claims 3 to 6, wherein The sulfonylaminoglyceryl glycoside has a structure shown in the following formula IV: In formula IV, m is 1-3, and the content of X is 30-70 mass %, preferably 35-55 mass %, and the content of Y is 20-50 mass %, preferably 25-40 mass % relative to the total amount of sulfonylaminoglyceryl glycoside; X and Y are each a group represented by the following formula IV-1) or a group represented by the following formula IV-2), and X and Y are different; In formula IV-1), R1 and R2 are each independently selected from an alkyl group having 1 to 3 carbon atoms, n is 1 to 10, o is 1 to 10, and p is 0 to 4.

8. The composition according to any one of claims 1 to 7, wherein The composition further contains aminocyclodextrin. Preferably, based on the total amount of the composition, the content of the aminocyclodextrin is 2-45% by mass, and more preferably 10-40% by mass.

9. The composition according to claim 8, wherein The aminocyclodextrin has a structure shown in the following formula V In formula V, based on the total amount of aminocyclodextrin, the content of R is 30-70 mass %, preferably 40-55 mass %, and R has the structure shown in the following structural formula i In formula i, m is 1-2, and n is 0-4.

10. Use of the composition according to any one of claims 1 to 9 in near-oil-based drilling fluid.

11. A near-oil-based drilling fluid containing the composition according to any one of claims 1 to 9.

12. The near-oil-based drilling fluid according to claim 11, wherein: Based on the total amount of the near-oil-based drilling fluid, the content of the composition is 20-60% by mass.

13. A method for preparing a near-oil-based drilling fluid base fluid, the method comprising: In parts by mass, 0-15 parts, preferably 3-12 parts of multi-branched polyetheramine, 0-45 parts, preferably 10-40 parts of aminocyclodextrin, 1-10 parts, preferably 3-7 parts of cationic chitosan, 40-60 parts, preferably 42-58 parts of silanylamino alkyl glycoside, and 0-30 parts, preferably 18-24 parts of sulfonylamino glyceryl glycoside are stirred and mixed uniformly at 60-85° C. under the protection of inert gas.

14. The preparation method according to claim 13, wherein: The inert gas is nitrogen and / or helium.

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