Ultrahigh-temperature salt-invasion-resistant composition for drilling fluid containing alkyl ketone derivative and preparation method of ultrahigh-temperature salt-invasion-resistant composition

Abstract

The invention discloses an ultra-high-temperature salt-invasion-resistant composition for drilling fluid containing an alkyl ketone derivative and a preparation method of the ultra-high-temperature salt-invasion-resistant composition, belongs to the technical field of drilling fluid, and solves the problem that the recognition selectivity of a treating agent of the existing drilling fluid is invalid under the ultra-high-temperature multi-ion mixed working condition. The composition comprises a functional alkane ketone recognition agent, a high-temperature-resistant multi-site complex polymer, an anti-interference ion regulator and a rheological filtration stabilizer, the functionalized alkyl ketone recognition agent contains oximido, sulfonic acid group and phosphonic acid group, and the high-temperature-resistant polymer is a quadripolymer. The preparation method comprises the following steps: preparing the functional alkyl ketone recognition agent and the high-temperature-resistant polymer, and mixing, pre-dispersing, curing and drying the components. The method can preferentially recognize and combine harmful divalent ions at the ultrahigh temperature of 200 DEG C or above, resists interference ion shielding, gives consideration to salt invasion resistance and rheological property, is controllable in process, is suitable for complex working conditions such as ultra-deep wells and the like, and has good industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of drilling fluid technology, specifically relating to an ultra-high temperature salt erosion resistant composition for drilling fluid containing alkane derivatives and its preparation method. Background Technology

[0002] As oil and gas exploration and development extend to extreme areas such as ultra-deep wells, ultra-deep water, complex fault blocks, and geothermal wells, the severity of drilling conditions continues to escalate. The synergistic effect of ultra-high temperatures and high salt intrusion has become a core bottleneck restricting the stability of drilling fluid performance and ensuring drilling safety. Currently, ultra-deep wells generally exceed 6000m in depth, with downhole temperatures reaching over 200℃, and some geothermal wells and hot dry rock wells even reaching 250℃. Simultaneously, complex formations often experience multi-type formation fluid cross-flow and formation mineral dissolution, leading to salt intrusion problems involving a mixture of various ions in the drilling fluid system, posing extremely high technical challenges to the salt resistance of drilling fluids.

[0003] Drilling fluid, as the "blood" of drilling engineering, directly determines drilling efficiency, wellbore stability, and reservoir protection effectiveness. Salt penetration resistance is one of the core indicators of drilling fluids in ultra-high temperature and complex formations. Salt penetration mainly originates from the contact between formation fluids and drilling fluids. When drilling fluid penetrates different lithological formations during drilling, it simultaneously comes into contact with multiple formation fluids. Specific scenarios include: in ultra-deep pre-salt carbonate reservoirs, the drilling fluid simultaneously comes into contact with high-concentration NaCl formation brine, CaCl2 / MgCl2 dissolved from gypsum salts, and HCO3 dissolved from carbonate rocks. - / CO3 2- And dissolved CO2; in complex fault-block oil and gas fields, due to fault connections, shallow freshwater in the upper part, brine in the middle salt layer, and sulfur-containing / CO2-containing formation fluids in the lower part are simultaneously returned, making the drilling fluid a multi-ion mixed system; in geothermal wells and hot dry rock drilling, geothermal fluids carry NaCl, Ca 2+ F - B4O7 2- Multiple anions and multiple cations coexist; in ultra-long horizontal sections of shale gas drilling, drilling fluid will simultaneously mix with formation water, fracturing flowback fluid and crude oil organic acids, forming a complex system with dual interference from small organic molecules and inorganic ions.

[0004] Under the aforementioned conditions of ultra-high temperature and mixed ions, drilling fluid treatment agents (such as filtration reducers, inhibitors, and chelating agents) generally suffer from selective failure due to ion-molecule specific recognition. Existing drilling fluid treatment agent molecules are all designed with specific binding sites, and their core design intention is to preferentially chelate or repel divalent ions (such as Ca2+) that are detrimental to drilling fluid performance. 2 + Mg 2+This avoids problems such as sudden changes in drilling fluid viscosity and shear, increased filtration loss, and deterioration of mud cake quality caused by these ions, while also being tolerant to monovalent ions (such as Na+). + K + The erosion of Ca. However, in ultra-high temperature environments (above 200℃), the binding sites of the treatment agent molecules will exhibit recognition confusion, specifically manifested as: [the text abruptly ends here, likely due to an incomplete sentence or missing information]. 2+ Mg 2+ Its specific binding ability is significantly reduced, and it preferentially binds to harmless or low-harm monovalent ions; some interfering ions (such as HCO3-) - CO3 2- Organic acid radicals can encapsulate the target harmful ions or shield the recognition sites of the treatment agent, preventing the treatment agent from effectively capturing Ca. 2+ Mg 2+ This ultimately leads to the failure of the drilling fluid's resistance to salt penetration, resulting in serious drilling accidents such as wellbore collapse, stuck pipe, and reservoir damage.

[0005] Currently, existing ultra-high temperature salt-resistant drilling fluid treatment agents in the industry mainly include sulfonated polymers (such as sulfonated phenolic resins and sulfonated lignite), polyacrylamide derivatives, and organophosphorus compounds. The design of these agents focuses on improving tolerance to single salts (such as NaCl and CaCl2), only addressing performance degradation caused by single-ion erosion, completely neglecting the issue of selective failure due to ion-molecule specific recognition in the presence of multiple ions. Under complex conditions of ultra-high temperature and multiple ion mixtures, these treatment agents generally suffer from the following defects: First, insufficient high-temperature stability; molecular chain breakage and hydrolysis easily occur above 200℃, leading to a sharp decline in salt resistance. Second, lack of selective ion recognition capability; they cannot preferentially bind to harmful divalent ions, nor can they repel harmless monovalent ions, making them unsuitable for salt invasion scenarios with multiple ions. Third, they are easily shielded by interfering ions; the treatment agent's recognition sites are easily blocked by HCO3-. - The following are some of the issues: 1) Blockage by organic acid radicals, which prevents the treatment agent from playing an effective role; 2) Poor compatibility with drilling fluid systems, with some treatment agents causing abnormal viscosity and shearing of the drilling fluid, affecting the rheological control of the drilling fluid.

[0006] Alkyl ketone derivatives have been attempted to be used in drilling fluid temperature and salt resistance fields in recent years due to their good high-temperature stability, hydrophobic and oleophilic balance and certain coordination ability. However, in the current technology, alkyl ketone derivatives are only used as conventional salt-resistant components. Their molecular structure has not been specifically designed and lacks the function of specifically recognizing harmful ions. They cannot solve the problem of selective failure under the coexistence of multiple ions. Under ultra-high temperature and multi-ion salt invasion conditions, performance degradation and failure will still occur, which is difficult to meet the drilling needs of ultra-deep wells and complex formations.

[0007] In summary, the current challenges in drilling in ultra-high temperature and complex formations, including the problems of multi-ion salt intrusion and selective failure of treatment agents based on ion-molecule specific recognition, represent a gap in the industry that cannot be addressed by existing technologies. Developing a ketone-containing derivative composition that can effectively solve the selective failure of recognition under multi-ion coexistence conditions in ultra-high temperature environments above 200℃, possesses excellent salt intrusion resistance, and exhibits good compatibility with drilling fluid systems is the core technical problem this invention aims to solve. Summary of the Invention

[0008] The purpose of this invention is to provide an ultra-high temperature salt erosion resistant composition for drilling fluid containing alkane derivatives and its preparation method, so as to solve the technical problems of multi-ion mixed salt erosion and selective failure of treatment agents in ultra-high temperature and complex formation drilling.

[0009] In a first aspect, the present invention provides an ultra-high temperature salt-resistant composition for drilling fluids containing alkane derivatives, comprising 25-40 parts of a functionalized alkane identifier, 18-30 parts of a high-temperature resistant multi-site complexing polymer, 6-15 parts of an anti-interference ion modifier, and 12-25 parts of a rheology filtration stabilizer; wherein the functionalized alkane identifier has the structural formula: HO-N=C(R2)-CH(R1)-CO-C6H3(SO3M1)(CH2PO(OM2)2), wherein R1 is H or CH3, R2 is H, CH3 or CH2COOH, and M1 and M2 are independently H, Na, and K, respectively. Or NH4; the high-temperature resistant multi-site complex polymer is a quaternary copolymer formed by copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and itaconic acid, whose repeating structural units include: [-CH2-CH(CONH2)-], [-CH2-C(CH3)(CONH-CH2-C(CH3)2-SO3M3)-], [-CH2-CH(N-vinylpyrrolidone)-], [-CH2-C(COOH)(CH2COOH)-]; wherein M3 is H, Na, K or NH4.

[0010] Furthermore, in the high-temperature resistant multi-site complex polymer, the molar percentage of each monomer is as follows: acrylamide: 30-45 mol%; 2-acrylamido-2-methylpropanesulfonic acid: 22-35 mol%; N-vinylpyrrolidone: 12-22 mol%; itaconic acid: 6-15 mol%.

[0011] Furthermore, the anti-interference ion modifier is one or two of hydroxyethylidene diphosphonic acid, aminotrimethylphosphonic acid, polyaspartic acid, or sodium citrate.

[0012] Furthermore, the rheology filtration stabilizer is a mixture of sulfonated lignite, sulfonated phenolic resin, and nano-silica, wherein the sulfonated lignite comprises 10-18 parts, the sulfonated phenolic resin comprises 2-6 parts, and the nano-silica comprises 0.5-3 parts.

[0013] Secondly, the present invention also provides a method for preparing an ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives, comprising the following steps: S1, preparing the functionalized alkane identifier; S2, preparing the high temperature resistant multi-site complex polymer; S3, mixing and pre-dispersing the components; S4, re-curing and drying to obtain the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

[0014] Furthermore, step S1 specifically includes the following steps:

[0015] S1.1, Sulfonation reaction:

[0016] Take 100 parts by weight of acetophenone and 200-400 parts by weight of solvent and add them to the reactor. The solvent is one of glacial acetic acid, dichloroethane, chloroform, and N,N-dimethylformamide. Cool to 0-10℃ and slowly add 80-140 parts by weight of sulfonating agent, which is one of chlorosulfonic acid, fuming sulfuric acid, and concentrated sulfuric acid. After the addition is complete, raise the temperature to 35-60℃ and react for 2-5 hours to obtain sulfonated acetophenone reaction solution.

[0017] S1.2, Phosphonic acid methylation reaction:

[0018] The sulfonated acetophenone reaction solution obtained in step S1.1 is cooled to 20-35℃, 50-120 parts by mass of formaldehyde solution and 60-130 parts by mass of phosphorous acid are added, the pH is adjusted to 1.0-3.0, the temperature is raised to 70-100℃ and reacted for 3-8 hours to introduce phosphonic acid methyl groups and obtain phosphonic acid intermediate reaction solution.

[0019] S1.3, Oxime reaction:

[0020] Add 80-150 parts by weight of hydroxylamine salt and alkaline solution to the phosphonate intermediate reaction solution obtained in step S1.2, adjust the pH to 4.5-7.0, heat to 50-85℃ and react for 2-6 hours to introduce oxime group and obtain crude reaction solution of functionalized alkane ketone recognizer.

[0021] S1.4, Neutralization, Purification and Drying:

[0022] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 is cooled to 20-30℃, the pH is adjusted to 6.5-8.5, and after filtering to remove insoluble matter, it is concentrated under reduced pressure. Anhydrous ethanol, isopropanol or acetone, 3-8 times its volume, are added to the concentrate for precipitation, and the solid is obtained by filtration. The obtained solid is washed with anhydrous ethanol 2-4 times and then vacuum dried at 50-80℃ and -0.06-(-0.09) MPa for 6-18 hours to obtain the functionalized alkane ketone identifier.

[0023] Further, in step S1.1, the molar ratio of acetophenone to sulfonating agent is 1:0.8-1:1.5; in step S1.2, the molar ratio of sulfonated acetophenone, formaldehyde, and phosphorous acid is 1:1.0-2.5:1.0-2.5, and the phosphorous acid can be replaced by a phosphite; the mass concentration of the formaldehyde solution is 30-40 wt%; in step S1.3, the hydroxylamine salt is hydroxylamine hydrochloride or hydroxylamine sulfate; the molar ratio of the phosphonate intermediate to the hydroxylamine salt is 1:1.0-2.0; and the alkaline solution is one of sodium hydroxide solution, potassium hydroxide solution, or ammonia water.

[0024] Further, step S2 specifically includes the following steps: S2.1, adding acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and itaconic acid to deionized water and adjusting the pH to 6-8; S2.2, adding a free radical initiator under nitrogen protection and polymerizing at 55-75℃ for 4-8 hours to obtain a high-temperature resistant multi-site complex polymer solution; S2.3, subjecting the polymer solution to precipitation, washing and drying to obtain the high-temperature resistant multi-site complex polymer.

[0025] Further, S3 specifically includes the following steps: S3.1, adding the functionalized alkane-ketone recognition agent, high-temperature resistant multi-site complexing polymer, anti-interference ion regulator and rheological filtration stabilizer into a mixing device according to the formula; S3.2, stirring at 40-70℃ for 0.5-2h to obtain the pre-dispersed compound material.

[0026] Further, S4 specifically includes the following steps: S4.1, maturing the pre-dispersed compound material at 50-80℃ for 1-4 hours; S4.2, spray drying or vacuum drying the maturated material; S4.3, pulverizing and sieving the dried material to obtain the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

[0027] The beneficial effects of this invention are as follows:

[0028] 1. This invention significantly improves the structural stability and ion recognition stability of the composition under ultra-high temperature conditions by introducing a functionalized alkane-ketone recognizer with a specific structure. The functionalized alkane-ketone recognizer molecule used in this invention simultaneously contains oxime, sulfonic acid, and phosphonic acid groups. The alkane-ketone skeleton has good thermal stability and can maintain a relatively stable molecular structure at high temperatures above 200°C. The sulfonic acid group endows it with good hydration and dispersibility and salt resistance. The phosphonic acid and oxime groups together provide multi-site recognition and complexation capabilities, thereby avoiding the problems of binding site instability and recognition confusion that occur in existing treatment agents under ultra-high temperature conditions.

[0029] 2. This invention can effectively improve the preferential recognition and stabilization of drilling fluids for harmful divalent ions under multi-ion mixed salt invasion conditions, reducing the risk of selective failure of ion-molecule specific recognition. The functionalized alkane-ketone recognizer of this invention has a high affinity for Ca... 2+ Mg 2+ Harmful divalent ions have a strong preferential action ability and can act on Na+. + K + Monovalent ions and HCO3-, CO32- 2- Even with the coexistence of interfering components such as organic acid radicals, it still maintains high recognition and binding efficiency, thereby effectively alleviating the problem of selective failure of recognition sites caused by the coexistence of multiple ions in existing technologies.

[0030] 3. This invention significantly enhances the system's resistance to salt intrusion by synergistically combining a functionalized alkane-ketone recognizer with a high-temperature resistant multi-site complexing polymer to form a multi-site complex and stable network structure. In this invention, the functionalized alkane-ketone recognizer provides rapid recognition and preferential capture of small molecules, while the high-temperature resistant multi-site complexing polymer further synergistically complexes and stably disperses target ions through various functional groups such as amide, sulfonic acid, lactam, and carboxyl groups. Together, they construct a multi-site synergistic network that effectively inhibits flocculation, thickening, water separation, and filtration deterioration caused by salt intrusion.

[0031] 4. This invention can effectively reduce the shielding effect of interfering anions on recognition sites, improving the pollution resistance performance under complex formation fluid conditions. By incorporating an anti-interference ion modifier, this invention can effectively control HCO3-. - CO3 2- It also has a regulatory effect on interfering ions such as organic acid radicals, reducing their encapsulation effect on target divalent ions and their competitive occupation of recognition sites, thereby increasing the probability of effective action of functionalized alkane-ketone recognition agents and high-temperature resistant multi-site complex polymers on harmful ions, and enhancing the stability of the composition under complex formation fluid pollution conditions.

[0032] 5. This invention can improve salt resistance while maintaining good rheological and filtration properties of drilling fluid. The rheological filtration stabilizer in this invention works synergistically with the aforementioned identification agent and complexing polymer to stabilize the dispersion of solid particles in drilling fluid under high temperature and high salinity conditions, optimize the mud cake structure, reduce filtration loss, and avoid the problems of abnormal drilling fluid viscosity and rheological deterioration caused by insufficient compatibility of some existing salt-resistant treatment agents. Thus, it balances salt resistance and rheological regulation performance.

[0033] 6. The preparation method of this invention has a clear process route, a wide range of raw material sources, and controllable reaction conditions, making it feasible for industrial implementation. This invention uses a combination of sulfonation, phosphonic acid methylation, and oxime conversion to prepare functionalized alkane-ketone recognition agents. The process steps are clear, and the reaction temperature, pH, and feed ratio ranges are well-defined, facilitating the control of the target product structure. Simultaneously, the preparation of the high-temperature resistant multi-site complex polymer employs a conventional free radical polymerization method, a mature process suitable for scale-up production and industrial application.

[0034] 7. This invention is particularly suitable for complex working conditions such as ultra-deep wells, geothermal wells, hot dry rock wells, and complex fault-block formations, exhibiting strong engineering applicability. Designed to address the challenges of ultra-high temperatures (200-250℃) and multi-ion mixed salt intrusion—conditions that existing technologies struggle to effectively handle—this invention meets the comprehensive requirements of drilling fluids in complex formations for high-temperature stability, salt resistance, contamination resistance, and compatibility. It plays a positive role in ensuring wellbore stability, reducing the risk of stuck pipe, and improving drilling safety.

[0035] 8. Compared with existing single salt-resistant or single temperature-resistant treatment agents, this invention has the comprehensive advantages of high temperature resistance, resistance to complex salt invasion, anti-interference ion shielding, and good system compatibility. Existing technologies mostly focus on solving performance problems under single salt or single temperature conditions, while this invention adopts a synergistic design from four aspects: functionalized small molecule recognition, polymer multi-site complexation, interference ion regulation, and rheological filtration stability, which can more comprehensively solve the multiple technical problems existing in the treatment of drilling fluids in ultra-high temperature complex formations. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein:

[0037] Figure 1 This is an image of the drilling fluid in experimental group A of test example 1 of the present invention;

[0038] Figure 2This is an image of the drilling fluid in control group B in Experiment Example 1 of this invention;

[0039] Figure 3 This is an image of the drilling fluid in control group C in Experiment Example 1 of this invention;

[0040] Figure 4 This is an image of the drilling fluid in control group D in Experiment Example 1 of this invention;

[0041] Figure 5 This is an image of the mud cake from Example 3 of Test Example 3 of the present invention;

[0042] Figure 6 This is an image of the mud cake from Comparative Example 1 in Experimental Example 3 of the present invention.

[0043] Figure 7 This is an image of the mud cake from Comparative Example 2 in Experimental Example 3 of the present invention.

[0044] Figure 8 This is an image of the mud cake from Comparative Example 3 in Experimental Example 3 of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0047] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0049] Example 1

[0050] This embodiment provides an ultra-high temperature salt erosion resistant composition for drilling fluids containing alkane derivatives, the composition of which is as follows:

[0051] Functionalized ketone recognition agent: 25 kg

[0052] High-temperature resistant multi-site complex polymer: 18 kg

[0053] Anti-interference ion regulator: 6 kg

[0054] Rheology filtration stabilizer: 12.5 kg

[0055] The rheology filtration stabilizer is composed of the following components:

[0056] Sulfonated lignite: 10 kg

[0057] Sulfonated phenolic resin: 2 kg

[0058] Nano-silica: 0.5 kg

[0059] The anti-interference ion regulator is hydroxyethylidene diphosphonic acid.

[0060] (I) Preparation of Functionalized Alkylketone Recognizers

[0061] S1.1 Sulfonation reaction:

[0062] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 200 kg of glacial acetic acid as a solvent and cool it to 0°C under stirring. Then slowly add 80 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 2 h. During the dropwise addition, the temperature of the reaction system should not exceed 10°C. After the dropwise addition is completed, heat the system to 35°C and keep it at that temperature for 2 h to obtain the sulfonated acetophenone reaction solution.

[0063] S1.2 Phosphonic acid methylation reaction:

[0064] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 20°C, and 50 kg of formaldehyde solution with a mass concentration of 30 wt% and 60 kg of phosphorous acid were added to adjust the pH of the system to 1.0. Then the temperature was raised to 70°C and kept at that temperature for 3 h to introduce phosphonic acid methyl groups and obtain the phosphonic acid intermediate reaction solution.

[0065] S1.3 Oxime reaction:

[0066] Add 80 kg of hydroxylamine hydrochloride to the phosphonate intermediate reaction solution obtained in step S1.2, and add sodium hydroxide solution to adjust the pH of the system to 4.5; then heat to 50℃ and keep the reaction at that temperature for 2 h to introduce the oxime group and obtain the crude reaction solution of the functionalized alkane ketone recognizer.

[0067] S1.4 Neutralization, purification, and drying:

[0068] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 was cooled to 20°C, and the pH of the system was adjusted to 6.5 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Anhydrous ethanol with a volume of 3 times its volume was added to the concentrate for precipitation, and the solid was obtained by filtration. The solid was then washed twice with anhydrous ethanol. Finally, the solid was dried under vacuum at 50°C and -0.06 MPa for 6 hours to obtain 25 kg of the functionalized alkane ketone identifier product.

[0069] (II) Preparation of high-temperature resistant multi-site complex polymers

[0070] In this embodiment, the molar percentage of each monomer in the high-temperature resistant multi-site complex polymer is as follows:

[0071] Acrylamide: 30 mol%

[0072] 2-Acrylamido-2-methylpropanesulfonic acid: 22 mol%

[0073] N-Vinylpyrrolidone: 12 mol%

[0074] Itaconic acid: 6 mol%

[0075] S2.1 Preparation of monomer solution:

[0076] Weigh 30 kg of acrylamide, 22 kg of 2-acrylamido-2-methylpropanesulfonic acid, 12 kg of N-vinylpyrrolidone, and 6 kg of itaconic acid, and add them to a reaction vessel; add 120 kg of deionized water, stir to dissolve, and adjust the pH of the system to 6.

[0077] S2.2 Polymerization reaction:

[0078] Nitrogen gas was introduced into the above system for protection for 30 min, followed by the addition of a free radical initiator, and the reaction was carried out at 55 °C for 4 h to obtain a high-temperature resistant multi-site complex polymer solution.

[0079] S2.3 Precipitation, washing and drying:

[0080] The obtained polymer solution was slowly added to 3 times its volume of anhydrous ethanol for precipitation, and the solid was obtained by filtration. The solid was then washed twice with anhydrous ethanol and dried under vacuum at 55°C for 8 h to obtain 18 kg of high-temperature resistant multi-site complex polymer product.

[0081] (III) Preparation of the composition

[0082] S3.1 Mixing and pre-dispersion:

[0083] Weigh out 25 kg of functionalized alkane ketone recognition agent, 18 kg of high-temperature resistant multi-site complexing polymer, 6 kg of hydroxyethylidene diphosphonic acid, 10 kg of sulfonated lignite, 2 kg of sulfonated phenolic resin, and 0.5 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0084] S3.2 Pre-dispersion:

[0085] The above materials were stirred at 40°C for 0.5 h to obtain a pre-dispersed compound material.

[0086] S4.1 Maturation:

[0087] The pre-dispersed compound material is transferred into a maturation device and matured at 50°C for 1 hour.

[0088] S4.2 Drying:

[0089] The matured material is then vacuum dried.

[0090] S4.3 Crushing and sieving:

[0091] The dried material is crushed and passed through a 100-mesh sieve to obtain the finished product of an ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

[0092] Example 2

[0093] This embodiment provides an ultra-high temperature salt erosion resistant composition for drilling fluids containing alkane derivatives, the composition of which is as follows:

[0094] Functionalized ketone recognition agent: 40 kg

[0095] High-temperature resistant multi-site complex polymer: 30 kg

[0096] Anti-interference ion regulator: 15 kg

[0097] Rheology filtration stabilizer: 27 kg

[0098] The rheology filtration stabilizer is composed of the following components:

[0099] Sulfonated lignite: 18 kg

[0100] Sulfonated phenolic resin: 6 kg

[0101] Nano-silica: 3 kg

[0102] The anti-interference ion regulator is aminotrimethylphosphonic acid.

[0103] (I) Preparation of Functionalized Alkylketone Recognizers

[0104] S1.1 Sulfonation reaction:

[0105] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 400 kg of glacial acetic acid as a solvent and cool it to 10°C under stirring. Then slowly add 140 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 3 h. During the dropwise addition, the temperature of the reaction system should not exceed 15°C. After the dropwise addition is completed, heat the system to 60°C and keep it at that temperature for 5 h to obtain the sulfonated acetophenone reaction solution.

[0106] S1.2 Phosphonic acid methylation reaction:

[0107] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 35°C, and 120 kg of formaldehyde solution with a mass concentration of 40 wt% and 130 kg of phosphorous acid were added to adjust the pH of the system to 3.0. Then the temperature was raised to 100°C and kept at that temperature for 8 h to introduce phosphonic acid methyl groups and obtain the phosphonic acid intermediate reaction solution.

[0108] S1.3 Oxime reaction:

[0109] 150 kg of hydroxylamine sulfate was added to the phosphonate intermediate reaction solution obtained in step S1.2, and sodium hydroxide solution was added to adjust the pH of the system to 7.0; then the temperature was raised to 85°C and kept at that temperature for 6 h to introduce the oxime group and obtain the crude reaction solution of the functionalized alkane ketone recognizer.

[0110] S1.4 Neutralization, purification, and drying:

[0111] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 was cooled to 30°C, and the pH of the system was adjusted to 8.5 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Anhydrous ethanol, eight times its volume, was added to the concentrate for precipitation, and the solid was obtained by filtration. The solid was then washed four times with anhydrous ethanol. Finally, the solid was dried under vacuum at 80°C and -0.09 MPa for 18 hours to obtain 40 kg of the functionalized alkane ketone identifier product.

[0112] (II) Preparation of high-temperature resistant multi-site complex polymers

[0113] In this embodiment, the molar percentage of each monomer in the high-temperature resistant multi-site complex polymer is as follows:

[0114] Acrylamide: 45 mol%

[0115] 2-Acrylamido-2-methylpropanesulfonic acid: 35 mol%

[0116] N-Vinylpyrrolidone: 22 mol%

[0117] Itaconic acid: 15 mol%

[0118] S2.1 Preparation of monomer solution:

[0119] Weigh 45 kg of acrylamide, 35 kg of 2-acrylamido-2-methylpropanesulfonic acid, 22 kg of N-vinylpyrrolidone, and 15 kg of itaconic acid, and add them to the reaction vessel; add 180 kg of deionized water, stir to dissolve, and adjust the pH of the system to 8.

[0120] S2.2 Polymerization reaction:

[0121] Nitrogen gas was introduced into the above system for protection for 45 min, followed by the addition of a free radical initiator, and the reaction was carried out at 75 °C for 8 h to obtain a high-temperature resistant multi-site complex polymer solution.

[0122] S2.3 Precipitation, washing and drying:

[0123] The obtained polymer solution was slowly added to 4 times its volume of anhydrous ethanol for precipitation, and the solid was obtained by filtration. The solid was then washed 4 times with anhydrous ethanol and dried under vacuum at 75°C for 12 h to obtain 30 kg of high-temperature resistant multi-site complex polymer product.

[0124] (III) Preparation of the composition

[0125] S3.1 Mixing and pre-dispersion:

[0126] Weigh out 40 kg of functionalized alkane-ketone recognition agent, 30 kg of high-temperature resistant multi-site complexing polymer, 15 kg of aminotrimethylphosphonic acid, 18 kg of sulfonated lignite, 6 kg of sulfonated phenolic resin, and 3 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0127] S3.2 Pre-dispersion:

[0128] The above materials were stirred at 70°C for 2 hours to obtain a pre-dispersed compound material.

[0129] S4.1 Maturation:

[0130] The pre-dispersed compound material is transferred into a maturation device and matured at 80°C for 4 hours.

[0131] S4.2 Drying:

[0132] The matured material is then spray-dried.

[0133] S4.3 Crushing and sieving:

[0134] The dried material is crushed and passed through an 80-mesh sieve to obtain the finished product of an ultra-high temperature salt resistant composition for drilling fluid containing ketone derivatives.

[0135] Example 3

[0136] This embodiment provides an ultra-high temperature salt erosion resistant composition for drilling fluids containing alkane derivatives, the composition of which is as follows:

[0137] Functionalized alkane-ketone recognition agent: 32.5 kg

[0138] High-temperature resistant multi-site complex polymer: 24 kg

[0139] Anti-interference ion regulator: 10.5 kg

[0140] Rheology filtration stabilizer: 19.75 kg

[0141] The rheology filtration stabilizer is composed of the following components:

[0142] Sulfonated lignite: 14 kg

[0143] Sulfonated phenolic resin: 4 kg

[0144] Nano-silica: 1.75 kg

[0145] The anti-interference ion regulator is selected from hydroxyethylidene diphosphonic acid and polyaspartic acid in a mass ratio of 1:1.

[0146] (I) Preparation of Functionalized Alkylketone Recognizers

[0147] S1.1 Sulfonation reaction:

[0148] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 300 kg of glacial acetic acid as a solvent and cool it to 5°C under stirring. Then slowly add 110 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 2.5 h. During the dropwise addition, the temperature of the reaction system should not exceed 12°C. After the dropwise addition is completed, heat the system to 47.5°C and keep it at this temperature for 3.5 h to obtain the sulfonated acetophenone reaction solution.

[0149] S1.2 Phosphonic acid methylation reaction:

[0150] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 27.5℃, and 85 kg of formaldehyde solution with a mass concentration of 35 wt% and 95 kg of phosphorous acid were added to adjust the pH of the system to 2.0. Then the temperature was raised to 85℃ and kept at that temperature for 5.5 h to introduce phosphonic acid methyl groups and obtain the phosphonic acid intermediate reaction solution.

[0151] S1.3 Oxime reaction:

[0152] 115 kg of hydroxylamine hydrochloride was added to the phosphonate intermediate reaction solution obtained in step S1.2, and sodium hydroxide solution was added to adjust the pH of the system to 5.75; then the temperature was raised to 67.5℃ and kept at the temperature for 4 h to introduce the oxime group and obtain the crude reaction solution of the functionalized alkane ketone recognizer.

[0153] S1.4 Neutralization, purification, and drying:

[0154] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 was cooled to 25°C, and the pH of the system was adjusted to 7.5 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Anhydrous ethanol, 5.5 times its volume, was added to the concentrate for precipitation. The solid was obtained by filtration and washed three times with anhydrous ethanol. Finally, the solution was vacuum dried at 65°C and -0.075 MPa for 12 h to obtain 32.5 kg of the functionalized alkane ketone identifier product.

[0155] (II) Preparation of high-temperature resistant multi-site complex polymers

[0156] In this embodiment, the molar percentage of each monomer in the high-temperature resistant multi-site complex polymer is as follows:

[0157] Acrylamide: 37.5 mol%

[0158] 2-Acrylamido-2-methylpropanesulfonic acid: 28.5 mol%

[0159] N-Vinylpyrrolidone: 17 mol%

[0160] Itaconic acid: 10.5 mol%

[0161] S2.1 Preparation of monomer solution:

[0162] Weigh 37.5 kg of acrylamide, 28.5 kg of 2-acrylamido-2-methylpropanesulfonic acid, 17 kg of N-vinylpyrrolidone, and 10.5 kg of itaconic acid, and add them to the reaction vessel; add 150 kg of deionized water, stir to dissolve, and adjust the pH of the system to 7.

[0163] S2.2 Polymerization reaction:

[0164] Nitrogen gas was introduced into the above system for protection for 35 min, followed by the addition of a free radical initiator, and the reaction was carried out at 65 °C for 6 h to obtain a high-temperature resistant multi-site complex polymer solution.

[0165] S2.3 Precipitation, washing and drying:

[0166] The obtained polymer solution was slowly added to 3.5 times its volume of anhydrous ethanol for precipitation, and the solid was obtained by filtration. The solid was then washed three times with anhydrous ethanol and dried under vacuum at 65°C for 10 h to obtain 24 kg of high-temperature resistant multi-site complex polymer product.

[0167] (III) Preparation of the composition

[0168] S3.1 Mixing and pre-dispersion:

[0169] Weigh out 32.5 kg of functionalized alkane-ketone recognition agent, 24 kg of high-temperature resistant multi-site complexing polymer, 10.5 kg of anti-interference ion regulator (5.25 kg of hydroxyethylidene diphosphonic acid + 5.25 kg of polyaspartic acid), 14 kg of sulfonated lignite, 4 kg of sulfonated phenolic resin, and 1.75 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0170] S3.2 Pre-dispersion:

[0171] The above materials were stirred at 55°C for 1.25 h to obtain a pre-dispersed compound material.

[0172] S4.1 Maturation:

[0173] The pre-dispersed compound material is transferred into a maturation device and maturated at 65°C for 2.5 h.

[0174] S4.2 Drying:

[0175] The matured material is then spray-dried.

[0176] S4.3 Crushing and sieving:

[0177] The dried material is crushed and passed through a 100-mesh sieve to obtain the finished product of an ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

[0178] Example 4

[0179] This embodiment provides an ultra-high temperature salt erosion resistant composition for drilling fluids containing alkane derivatives, the composition of which is as follows:

[0180] Functionalized ketone recognition agent: 29 kg

[0181] High-temperature resistant multi-site complex polymer: 21 kg

[0182] Anti-interference ion regulator: 8 kg

[0183] Rheology filtration stabilizer: 16.2 kg

[0184] The rheology filtration stabilizer is composed of the following components:

[0185] Sulfonated lignite: 12 kg

[0186] Sulfonated phenolic resin: 3 kg

[0187] Nano-silica: 1.2 kg

[0188] The anti-interference ion regulator is selected from hydroxyethylidene diphosphonic acid and sodium citrate in a mass ratio of 3:1.

[0189] (I) Preparation of Functionalized Alkylketone Recognizers

[0190] S1.1 Sulfonation reaction:

[0191] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 260 kg of glacial acetic acid as a solvent and cool it to 4°C under stirring. Then slowly add 95 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 2.2 h. During the dropwise addition, the temperature of the reaction system should not exceed 10°C. After the dropwise addition is completed, heat the system to 42°C and keep it at that temperature for 3 h to obtain the sulfonated acetophenone reaction solution.

[0192] S1.2 Phosphonic acid methylation reaction:

[0193] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 24°C, and 70 kg of formaldehyde solution with a mass concentration of 33 wt% and 80 kg of sodium phosphite were added to adjust the pH of the system to 1.6. Then the temperature was raised to 78°C and kept at that temperature for 4.5 h to introduce phosphonic acid methyl groups and obtain the phosphonic acid intermediate reaction solution.

[0194] S1.3 Oxime reaction:

[0195] 100 kg of hydroxylamine hydrochloride was added to the phosphonate intermediate reaction solution obtained in step S1.2, and sodium hydroxide solution was added to adjust the pH of the system to 5.2; then the temperature was raised to 60°C and kept at that temperature for 3.5 h to introduce the oxime group and obtain the crude reaction solution of the functionalized alkane ketone recognizer.

[0196] S1.4 Neutralization, purification, and drying:

[0197] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 was cooled to 23°C, and the pH of the system was adjusted to 7.0 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Anhydrous ethanol, 4.5 times its volume, was added to the concentrate for precipitation. The solid was obtained by filtration and washed three times with anhydrous ethanol. Finally, the solution was vacuum dried at 60°C and -0.07 MPa for 10 h to obtain 29 kg of the functionalized alkane ketone identifier product.

[0198] (II) Preparation of high-temperature resistant multi-site complex polymers

[0199] In this embodiment, the molar percentage of each monomer in the high-temperature resistant multi-site complex polymer is as follows:

[0200] Acrylamide: 34 mol%

[0201] 2-Acrylamido-2-methylpropanesulfonic acid: 25 mol%

[0202] N-Vinylpyrrolidone: 14 mol%

[0203] Itaconic acid: 8 mol%

[0204] S2.1 Preparation of monomer solution:

[0205] Weigh out 34 kg of acrylamide, 25 kg of 2-acrylamido-2-methylpropanesulfonic acid, 14 kg of N-vinylpyrrolidone, and 8 kg of itaconic acid, and add them to the reaction vessel; add 135 kg of deionized water, stir to dissolve, and adjust the pH of the system to 6.5.

[0206] S2.2 Polymerization reaction:

[0207] Nitrogen gas was introduced into the above system for protection for 32 min, followed by the addition of a free radical initiator, and the reaction was carried out at 60 °C for 5 h to obtain a high-temperature resistant multi-site complex polymer solution.

[0208] S2.3 Precipitation, washing and drying:

[0209] The obtained polymer solution was slowly added to 3.2 times its volume of anhydrous ethanol for precipitation, and the solid was obtained by filtration. The solid was then washed three times with anhydrous ethanol and dried under vacuum at 60°C for 9 h to obtain 21 kg of high-temperature resistant multi-site complex polymer product.

[0210] (III) Preparation of the composition

[0211] S3.1 Mixing and pre-dispersion:

[0212] Weigh out 29 kg of functionalized alkane-ketone recognition agent, 21 kg of high-temperature resistant multi-site complexing polymer, 8 kg of anti-interference ion regulator (6 kg of hydroxyethylidene diphosphonic acid + 2 kg of sodium citrate), 12 kg of sulfonated lignite, 3 kg of sulfonated phenolic resin, and 1.2 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0213] S3.2 Pre-dispersion:

[0214] The above materials were stirred at 48°C for 0.9 h to obtain a pre-dispersed compound material.

[0215] S4.1 Maturation:

[0216] The pre-dispersed compound material was transferred into a maturation device and matured at 58°C for 1.8 h.

[0217] S4.2 Drying:

[0218] The matured material is then vacuum dried.

[0219] S4.3 Crushing and sieving:

[0220] The dried material is crushed and passed through a 100-mesh sieve to obtain the finished product of an ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

[0221] Example 5

[0222] This embodiment provides an ultra-high temperature salt erosion resistant composition for drilling fluids containing alkane derivatives, the composition of which is as follows:

[0223] Functionalized ketone recognition agent: 36 kg

[0224] High-temperature resistant multi-site complex polymer: 27 kg

[0225] Anti-interference ion regulator: 13 kg

[0226] Rheology filtration stabilizer: 23.4 kg

[0227] The rheology filtration stabilizer is composed of the following components:

[0228] Sulfonated lignite: 16 kg

[0229] Sulfonated phenolic resin: 5 kg

[0230] Nano-silica: 2.4 kg

[0231] The anti-interference ion regulator is selected from hydroxyethylidene diphosphonic acid and aminotrimethylphosphonic acid in a mass ratio of 2:1.

[0232] (I) Preparation of Functionalized Alkylketone Recognizers

[0233] S1.1 Sulfonation reaction:

[0234] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 350 kg of glacial acetic acid as a solvent and cool it to 8°C under stirring. Then slowly add 125 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 2.8 h. During the dropwise addition, the temperature of the reaction system should not exceed 13°C. After the dropwise addition is completed, heat the system to 55°C and keep it at that temperature for 4.5 h to obtain the sulfonated acetophenone reaction solution.

[0235] S1.2 Phosphonic acid methylation reaction:

[0236] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 32°C, and 105 kg of formaldehyde solution with a mass concentration of 38 wt% and 115 kg of potassium phosphite were added to adjust the pH of the system to 2.6. Then the temperature was raised to 95°C and kept at that temperature for 7 h to introduce phosphonic acid methyl groups and obtain the phosphonic acid intermediate reaction solution.

[0237] S1.3 Oxime reaction:

[0238] 135 kg of hydroxylamine sulfate was added to the phosphonate intermediate reaction solution obtained in step S1.2, and sodium hydroxide solution was added to adjust the pH of the system to 6.6; then the temperature was raised to 80°C and kept at that temperature for 5.5 h to introduce the oxime group and obtain the crude reaction solution of the functionalized alkane ketone recognizer.

[0239] S1.4 Neutralization, purification, and drying:

[0240] The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 was cooled to 28°C, and the pH of the system was adjusted to 8.2 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Seven times its volume of anhydrous ethanol was added to the concentrate for precipitation, and the solid was obtained by filtration. The solid was then washed four times with anhydrous ethanol. Finally, the solution was vacuum dried at 75°C and -0.085 MPa for 16 h to obtain 36 kg of the functionalized alkane ketone identifier product.

[0241] (II) Preparation of high-temperature resistant multi-site complex polymers

[0242] In this embodiment, the molar percentage of each monomer in the high-temperature resistant multi-site complex polymer is as follows:

[0243] Acrylamide: 41 mol%

[0244] 2-Acrylamido-2-methylpropanesulfonic acid: 32 mol%

[0245] N-Vinylpyrrolidone: 20 mol%

[0246] Itaconic acid: 13 mol%

[0247] S2.1 Preparation of monomer solution:

[0248] Weigh 41 kg of acrylamide, 32 kg of 2-acrylamido-2-methylpropanesulfonic acid, 20 kg of N-vinylpyrrolidone, and 13 kg of itaconic acid, and add them to the reaction vessel; add 165 kg of deionized water, stir to dissolve, and adjust the pH of the system to 7.6.

[0249] S2.2 Polymerization reaction:

[0250] Nitrogen gas was introduced into the above system for protection for 40 min, followed by the addition of a free radical initiator, and the reaction was carried out at 70 °C for 7 h to obtain a high-temperature resistant multi-site complex polymer solution.

[0251] S2.3 Precipitation, washing and drying:

[0252] The obtained polymer solution was slowly added to 3.8 times its volume of anhydrous ethanol for precipitation, and the solid was filtered off. The solid was then washed four times with anhydrous ethanol and dried under vacuum at 70°C for 11 h to obtain 27 kg of high-temperature resistant multi-site complex polymer product.

[0253] (III) Preparation of the composition

[0254] S3.1 Mixing and pre-dispersion:

[0255] Weigh out 36 kg of functionalized alkane-ketone recognition agent, 27 kg of high-temperature resistant multi-site complexing polymer, 13 kg of anti-interference ion regulator (8.67 kg of hydroxyethylidene diphosphonic acid + 4.33 kg of aminotrimethylphosphonic acid), 16 kg of sulfonated lignite, 5 kg of sulfonated phenolic resin, and 2.4 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0256] S3.2 Pre-dispersion:

[0257] The above materials were stirred at 62°C for 1.6 h to obtain a pre-dispersed compound material.

[0258] S4.1 Maturation:

[0259] The pre-dispersed compound material was transferred into a maturation device and matured at 72°C for 3.2 h.

[0260] S4.2 Drying:

[0261] The matured material is then spray-dried.

[0262] S4.3 Crushing and sieving:

[0263] The dried material is crushed and passed through an 80-mesh sieve to obtain the finished product of an ultra-high temperature salt resistant composition for drilling fluid containing ketone derivatives.

[0264] Comparative Example 1

[0265] This comparative example provides a basic drilling fluid system that does not include the ultra-high temperature salt erosion resistant drilling fluid composition containing ketone derivatives as described in this invention, but only uses a conventional drilling fluid formulation.

[0266] Basic drilling fluid formulation

[0267] Bentonite: 40 kg

[0268] Soda ash (Na2CO3): 3 kg

[0269] Sodium carboxymethyl cellulose (CMC-HV): 8 kg

[0270] Sulfonated phenolic resin (SMP-2): 15 kg

[0271] Sulfonated lignite (SMC): 15 kg

[0272] Deionized water: 1000 kg

[0273] Preparation steps:

[0274] S1 Basic Slurry Preparation:

[0275] Add 1000 kg of deionized water to a mixing tank, add 3 kg of soda ash, and stir to dissolve; then add 40 kg of bentonite and stir at high speed for 30 min to fully hydrate and disperse the bentonite, thus obtaining a bentonite-based slurry.

[0276] S2 treatment agent added:

[0277] Add 8 kg of CMC-HV, 15 kg of sulfonated phenolic resin, and 15 kg of sulfonated lignite to the above base slurry in sequence. Stir for 15 min after each addition of a treatment agent to ensure that the solution is fully dissolved and dispersed to obtain the base drilling fluid.

[0278] S3 Salt Intrusion Simulation Treatment:

[0279] Add 100 kg NaCl, 30 kg CaCl2, 10 kg MgCl2, 10 kg NaHCO3, and 5 kg sodium acetate to the above-mentioned basic drilling fluid, stir evenly, and simulate the salt invasion condition of multi-ion mixed salt invasion to obtain the salt-invaded basic drilling fluid.

[0280] S4 High Temperature Aging:

[0281] The salt-treated base drilling fluid was placed in a high-temperature, high-pressure aging tank and aged at 200°C for 16 hours. After being removed and cooled to room temperature, the drilling fluid performance was tested.

[0282] Comparative Example 2

[0283] This comparative example provides a drilling fluid composition containing a common alkane derivative, in which a non-functionalized common acetophenone derivative (containing only a single sulfonic acid group, without phosphonic acid groups and oxime groups) is used to replace the functionalized alkane ketone identifier in this invention. The remaining components and amounts are consistent with those in Example 3, which is used to verify the necessity of the synergistic design of multifunctional groups in the functionalized alkane ketone identifier.

[0284] Composition Formulation

[0285] Common sulfonated acetophenone derivative: 32.5 kg

[0286] High-temperature resistant multi-site complex polymer: 24 kg

[0287] Anti-interference ion regulator: 10.5 kg (5.25 kg of hydroxyethylidene diphosphonic acid + 5.25 kg of polyaspartic acid)

[0288] Rheology filtration stabilizer: 19.75 kg (14 kg sulfonated lignite + 4 kg sulfonated phenolic resin + 1.75 kg nano silica)

[0289] Preparation of common sulfonated acetophenone derivatives

[0290] S1.1 Sulfonation reaction:

[0291] Take 100 kg of acetophenone and add it to the reaction vessel. Then add 300 kg of glacial acetic acid as a solvent and cool it to 5°C under stirring. Then slowly add 110 kg of chlorosulfonic acid dropwise, controlling the dropwise addition time to 2.5 h. During the dropwise addition, the temperature of the reaction system should not exceed 12°C. After the dropwise addition is completed, heat the system to 47.5°C and keep it at this temperature for 3.5 h to obtain the sulfonated acetophenone reaction solution.

[0292] S1.2 Neutralization, purification, and drying:

[0293] The sulfonated acetophenone reaction solution obtained in step S1.1 was cooled to 25°C, and the pH of the system was adjusted to 7.5 with sodium hydroxide solution. After filtering to remove insoluble matter, the solution was concentrated under reduced pressure. Anhydrous ethanol, five times its volume, was added to the concentrate for precipitation, and the solid was obtained by filtration. The solid was then washed three times with anhydrous ethanol. Finally, the solid was dried under vacuum at 65°C and -0.075 MPa for 12 h to obtain 32.5 kg of the ordinary sulfonated acetophenone derivative product.

[0294] Preparation of high-temperature resistant multi-site complex polymers

[0295] The same steps as in Example 3 (II) for preparing the high-temperature resistant multi-site complex polymer.

[0296] Preparation of the composition:

[0297] S3.1 Mixing and pre-dispersion:

[0298] Weigh out 32.5 kg of ordinary sulfonated acetophenone derivative, 24 kg of high-temperature resistant multi-site complexing polymer, 10.5 kg of anti-interference ion regulator, 14 kg of sulfonated lignite, 4 kg of sulfonated phenolic resin, and 1.75 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0299] S3.2 Pre-dispersion:

[0300] The above materials were stirred at 55°C for 1.25 h to obtain a pre-dispersed compound material.

[0301] S4.1 Maturation:

[0302] The pre-dispersed compound material is transferred into a maturation device and maturated at 65°C for 2.5 h.

[0303] S4.2 Drying:

[0304] The matured material is then spray-dried.

[0305] S4.3 Crushing and sieving:

[0306] The dried material was crushed and passed through a 100-mesh sieve to obtain the finished product of the composition of Comparative Example 2.

[0307] Comparative Example 3

[0308] This comparative example provides a drilling fluid composition without the high-temperature resistant multi-site complexing polymer to verify the necessity of the synergistic effect between the functionalized alkane-ketone identifier and the high-temperature resistant multi-site complexing polymer. In this comparative example, the high-temperature resistant multi-site complexing polymer is removed, while the remaining components and amounts are consistent with Example 3. The amount of the high-temperature resistant multi-site complexing polymer is replaced by an equal amount of sulfonated lignite to maintain a substantially unchanged total solids content.

[0309] Composition Formulation

[0310] Functionalized alkane-ketone recognition agent: 32.5 kg

[0311] High-temperature resistant multi-site complex polymer: 0 kg (without additives)

[0312] Anti-interference ion regulator: 10.5 kg (5.25 kg of hydroxyethylidene diphosphonic acid + 5.25 kg of polyaspartic acid)

[0313] Rheology filtration stabilizer: 43.75 kg (sulfonated lignite 38 kg + sulfonated phenolic resin 4 kg + nano silica 1.75 kg)

[0314] Preparation of Functionalized Alkyl Ketone Recognizers

[0315] The same preparation steps as in Example 3 (I) for the functionalized alkane-ketone recognition agent.

[0316] Preparation of the composition:

[0317] S3.1 Mixing and pre-dispersion:

[0318] Weigh out 32.5 kg of functionalized alkane ketone identification agent, 10.5 kg of anti-interference ion regulator, 38 kg of sulfonated lignite, 4 kg of sulfonated phenolic resin, and 1.75 kg of nano-silica according to the formula, and put them into the mixing equipment.

[0319] S3.2 Pre-dispersion:

[0320] The above materials were stirred at 55°C for 1.25 h to obtain a pre-dispersed compound material.

[0321] S4.1 Maturation:

[0322] The pre-dispersed compound material is transferred into a maturation device and maturated at 65°C for 2.5 h.

[0323] S4.2 Drying:

[0324] The matured material is then spray-dried.

[0325] S4.3 Crushing and sieving:

[0326] The dried material was crushed and passed through a 100-mesh sieve to obtain the finished product of the composition of Comparative Example 3.

[0327] Drilling fluid preparation and salt aging test

[0328] The above-mentioned composition of Comparative Example 3 was added to the base drilling fluid at a dosage of 3 wt%. After stirring evenly, the same composite salt immersion solution as that of Comparative Example 1 was added. After aging at 200℃ for 16 h, the drilling fluid performance was tested.

[0329] Experimental Example 1

[0330] Image verification test of the appearance stability of drilling fluid after composite salt intrusion and high-temperature aging

[0331] To verify the effect of the composition of the present invention on improving the stability of drilling fluid system under ultra-high temperature and multi-ion mixed salt invasion conditions, the samples obtained from Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were selected for appearance stability comparison test, and the results were characterized by images.

[0332] 1. Experimental Materials and Grouping

[0333] The basic drilling fluid formula is: 40 kg bentonite, 3 kg soda ash, 8 kg sodium carboxymethyl cellulose, and 1000 kg deionized water.

[0334] The experimental groups are as follows:

[0335] Experimental Group A: The composition obtained in Example 3 was added to the base drilling fluid at an amount of 3 wt% of the total mass of the drilling fluid.

[0336] Control group B: Basic drilling fluid, without the composition of this invention;

[0337] Control group C: The composition obtained in Comparative Example 2 was added to the base drilling fluid at an amount of 3 wt% of the total mass of the drilling fluid.

[0338] Control group D: The composition obtained from Comparative Example 3 was added to the base drilling fluid at an amount of 3 wt% of the total mass of the drilling fluid.

[0339] Subsequently, a composite salt immersion medium was added to each group of samples. The composite salt immersion medium consisted of: 10 wt% NaCl, 3 wt% CaCl2, 1 wt% MgCl2, 1 wt% NaHCO3, and 0.5 wt% sodium acetate.

[0340] 2. Experimental Procedure

[0341] (1) After stirring each group of drilling fluid evenly, put it into a high-temperature aging tank;

[0342] (2) Aging at 200℃ for 16 h;

[0343] (3) After aging is complete, allow it to cool naturally to room temperature;

[0344] (4) Transfer each group of samples to a transparent graduated cylinder and let stand for 2 hours;

[0345] (5) Take photos of the samples after they have been left to stand to obtain comparison pictures of the appearance of the drilling fluid after aging.

[0346] 3. Image Results

[0347] The captured images are used as Figure 1-4 .

[0348] Figure 1 As can be seen in:

[0349] After standing for 2 hours, the drilling fluid sample corresponding to Example 3 in test group A showed that the system was in a uniform fluid state, the liquid column was of consistent color, there was no obvious stratification, no obvious supernatant precipitation was observed, and there was little sedimentation at the bottom, indicating that the system had good dispersion stability.

[0350] Figure 2 As can be seen in:

[0351] The control group B, corresponding to the comparative sample 1, showed obvious stratification, with more clear liquid precipitating in the upper part and obvious sedimentation at the bottom, indicating that the basic drilling fluid had poor stability under the conditions of compound salt invasion and high temperature.

[0352] Figure 3 As can be seen in:

[0353] Although the control group C, corresponding to the comparative sample 2, showed some improvement compared to the control group B, some degree of clear liquid precipitation and local flocculation and aggregation were still observed, indicating that ordinary sulfonated ketone derivatives are difficult to effectively maintain the stability of the system.

[0354] Figure 4 As can be seen in:

[0355] The bottom deposition of the control group D sample (comparative example 3) was significantly greater than that of the experimental group A, and the dispersion uniformity was poor after standing. This indicates that the system's resistance to salt invasion decreases when high-temperature resistant multi-site complexing polymers are lacking.

[0356] 4. Results Analysis

[0357] Depend on Figure 1-4 It can be clearly seen that, after combined salt invasion and aging at 200°C, the drilling fluid system in Example 3 of this invention still maintains good homogeneity and suspension stability, which is significantly better than the blank control and the single-component substitution system. This result indicates that the composition of this invention can effectively mitigate particle aggregation, sedimentation, and stratification caused by multi-ion mixed salt invasion, thereby significantly improving the stability of the drilling fluid system.

[0358] Experimental Example 2

[0359] To quantitatively evaluate the technical effects of the compositions of the present invention, drilling fluid performance tests were conducted using samples obtained in Examples 1-5 and Comparative Examples 1-3, respectively. The test conditions were as follows: 3 wt% of each sample was added to the base drilling fluid, followed by the addition of a composite salt-impregnation medium (NaCl 10 wt%, CaCl2 3 wt%, MgCl2 1 wt%, NaHCO3 1 wt%, sodium acetate 0.5 wt%). After aging at 200℃ for 16 h, apparent viscosity (AV), plastic viscosity (PV), dynamic shear force (YP), and high-temperature high-pressure filtration loss (HTHP FL) were measured.

[0360] The test results are shown in Table 1.

[0361] Table 1 Drilling fluid performance test results

[0362]

[0363] Results Analysis

[0364] As shown in Table 1, the drilling fluid systems corresponding to Examples 1-5 all exhibited superior overall performance compared to Comparative Examples 1-3 under high-temperature and combined salt invasion conditions. In particular, Examples 2, 3, and 5 effectively reduced high-temperature and high-pressure filtration loss while maintaining high rheological parameters, indicating that the composition of the present invention can not only improve the salt invasion resistance of drilling fluids but also take into account rheological properties and filtration loss control performance.

[0365] Among them, Comparative Example 1 had the worst overall performance, indicating that the basic drilling fluid was difficult to maintain stability under ultra-high temperature composite salt invasion conditions; Comparative Example 2 was improved compared to Comparative Example 1, but its performance was still significantly lower than that of the Example Group because the ordinary sulfonated ketone derivative lacked the specific functional groups in this invention; Comparative Example 3 showed some improvement, but there was still a gap compared with the Example Group, indicating that when relying solely on functionalized ketone recognition agents without high temperature resistant multi-site complexing polymers, the overall stability and filtration control capabilities of the system were still insufficient.

[0366] In summary, the composition of the present invention exhibits excellent technical performance under ultra-high temperature and multi-ion mixed salt invasion conditions, verifying its application value in the field of drilling fluids.

[0367] Experimental Example 3

[0368] Image verification test of sludge cake quality after high temperature and high pressure filtration

[0369] To verify the improvement effect of the composition of the present invention on drilling fluid cake quality and filtration loss control performance, samples obtained from Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were selected for high temperature and high pressure filtration loss tests, and the results were characterized using actual images of the cake.

[0370] 1. Experimental Materials and Grouping

[0371] The drilling fluid used in the experiment was prepared in the same way as in Experiment 1, that is, the same concentration of composite salt invasion medium was added to the preparation of the three groups of Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3.

[0372] All samples were aged at 200℃ for 16 h and then cooled to room temperature before undergoing high-temperature and high-pressure filtration loss testing.

[0373] 2. Experimental Procedure

[0374] (1) Each group of aged drilling fluid samples was loaded into a high-temperature and high-pressure filter;

[0375] (2) Conduct a filtration loss test under the specified test pressure and temperature conditions;

[0376] (3) Remove the mud cake from the filter paper after filtration is complete;

[0377] (4) After letting the mud cake sit naturally for 5 minutes, take a picture to obtain a comparison picture of the appearance of the mud cake.

[0378] 3. Image Results

[0379] The captured images are Figure 5-8 .

[0380] Figure 5 As can be seen in:

[0381] Example 3 corresponds to a mud cake with a relatively flat surface, a relatively thin overall structure and a dense structure, intact edges, and no obvious cracks or holes;

[0382] Figure 6 As can be seen in:

[0383] The mud cake in Comparative Example 1 was significantly thicker, with a rough surface, localized looseness, and incomplete edges, indicating poor drilling fluid loss control.

[0384] Figure 7 As can be seen in:

[0385] Although the mud cake corresponding to Comparative Example 2 was slightly improved compared to Comparative Example 1, it still had problems such as uneven surface and local looseness.

[0386] Figure 8 As can be seen in:

[0387] The integrity of the mud cake in Comparative Example 3 was lower than that in Example 3, and the thickness of the mud cake was significantly greater than that in Example 3, indicating that the system's ability to form a dense mud cake was insufficient without the presence of a high-temperature resistant multi-site complexing polymer.

[0388] 4. Results Analysis

[0389] Depend on Figure 5-8 It can be clearly seen that the drilling fluid corresponding to Example 3 of the present invention can form a thinner, denser, and more complete mud cake, indicating that the composition of the present invention still has a good filtration loss control effect under ultra-high temperature and multi-ion mixed salt invasion conditions.

[0390] The comparative results show that ordinary alkane derivatives or systems lacking high-temperature resistant multi-site complexing polymers are difficult to achieve the cake quality level of the composition of this invention, which indirectly proves that there is a significant synergistic effect between the functionalized alkane recognition agent and the high-temperature resistant multi-site complexing polymer in this invention.

[0391] The above experimental results show that the ultra-high temperature salt erosion resistant composition for drilling fluid containing ketone derivatives provided by the present invention can significantly improve the rheological stability, filtration loss control capability and system dispersion stability of drilling fluid under ultra-high temperature and multi-ion mixed salt erosion conditions, and has good engineering application prospects.

[0392] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-temperature salt-resistant composition for drilling fluids containing ketone derivatives, characterized in that, It includes 25-40 parts of functionalized alkane-ketone recognition agent, 18-30 parts of high temperature resistant multi-site complexing polymer, 6-15 parts of anti-interference ion regulator, and 12-25 parts of rheological filtration stabilizer. The functionalized alkane-ketone recognizer has the following structural formula: HO-N=C(R2)-CH(R1)-CO-C6H3(SO3M1)(CH2PO(OM2)2), Where R1 is H or CH3, R2 is H, CH3 or CH2COOH, and M1 and M2 are independently H, Na, K or NH4; The high-temperature resistant multi-site complex polymer is a quaternary copolymer formed by copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, and itaconic acid, and its repeating structural units include: [-CH2-CH(CONH2)-], [-CH2-C(CH3)(CONH-CH2-C(CH3)2-SO3M3)-], [-CH2-CH(N-vinylpyrrolidone)-], and [-CH2-C(COOH)(CH2COOH)-]. M3 is H, Na, K or NH4; The anti-interference ion modifier is one or two of hydroxyethylidene diphosphonic acid, aminotrimethylphosphonic acid, polyaspartic acid, or sodium citrate. The rheology filtration stabilizer is a mixture of sulfonated lignite, sulfonated phenolic resin and nano silica, wherein the sulfonated lignite comprises 10-18 parts, the sulfonated phenolic resin comprises 2-6 parts, and the nano silica comprises 0.5-3 parts.

2. The ultra-high temperature salt resistant composition for drilling fluid containing ketone derivatives according to claim 1, characterized in that, In the high-temperature resistant multi-site complex polymer, the molar percentage of each monomer is as follows: Acrylamide: 30-45 mol% 2-Acrylamido-2-methylpropanesulfonic acid 22-35 mol%, N-vinylpyrrolidone 12-22 mol%, Itaconic acid: 6-15 mol%.

3. A method for preparing an ultra-high temperature salt-resistant drilling fluid composition containing ketone derivatives as described in any one of claims 1 or 2, characterized in that, Includes the following steps: S1. Prepare the functionalized alkane-ketone recognition agent; S2. Prepare the high-temperature resistant multi-site complex polymer; S3. Pre-dispersion of each component; S4. Further aging and drying to obtain the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

4. The method for preparing the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives according to claim 3, characterized in that, S1 specifically includes the following steps: S1.1, Sulfonation reaction: Take 100 parts by weight of acetophenone and 200-400 parts by weight of solvent and add them to the reactor. The solvent is one of glacial acetic acid, dichloroethane, chloroform, and N,N-dimethylformamide. Cool to 0-10℃ and slowly add 80-140 parts by weight of sulfonating agent, which is one of chlorosulfonic acid, fuming sulfuric acid, and concentrated sulfuric acid. After the addition is complete, raise the temperature to 35-60℃ and react for 2-5 hours to obtain sulfonated acetophenone reaction solution. S1.2, Phosphonic acid methylation reaction: The sulfonated acetophenone reaction solution obtained in step S1.1 is cooled to 20-35℃, 50-120 parts by mass of formaldehyde solution and 60-130 parts by mass of phosphorous acid are added, the pH is adjusted to 1.0-3.0, the temperature is raised to 70-100℃ and reacted for 3-8 hours to introduce phosphonic acid methyl groups and obtain phosphonic acid intermediate reaction solution. S1.3, Oxime reaction: Add 80-150 parts by weight of hydroxylamine salt and alkaline solution to the phosphonate intermediate reaction solution obtained in step S1.2, adjust the pH to 4.5-7.0, heat to 50-85℃ and react for 2-6 hours to introduce oxime group and obtain crude reaction solution of functionalized alkane ketone recognizer. S1.4, Neutralization, Purification and Drying: The crude reaction solution of the functionalized alkane ketone identifier obtained in step S1.3 is cooled to 20-30℃, the pH is adjusted to 6.5-8.5, and after filtering to remove insoluble matter, it is concentrated under reduced pressure. Anhydrous ethanol, isopropanol or acetone, 3-8 times its volume, are added to the concentrate for precipitation, and the solid is obtained by filtration. The obtained solid is washed with anhydrous ethanol 2-4 times and then vacuum dried at 50-80℃ and -0.06-(-0.09) MPa for 6-18 hours to obtain the functionalized alkane ketone identifier.

5. The method for preparing the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives according to claim 4, characterized in that, In step S1.1, the molar ratio of acetophenone to sulfonating agent is 1:0.8-1:1.5; In step S1.2, the molar ratio of sulfonated acetophenone, formaldehyde, and phosphorous acid is 1:1.0-2.5:1.0-2.5; the mass concentration of the formaldehyde solution is 30-40 wt%, and the phosphorous acid can be replaced by phosphite. In S1.3, the hydroxylamine salt is hydroxylamine hydrochloride or hydroxylamine sulfate; the molar ratio of the phosphonate intermediate to the hydroxylamine salt is 1:1.0-2.0; and the alkaline solution is one of sodium hydroxide solution, potassium hydroxide solution, or ammonia solution.

6. The method for preparing the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives according to claim 3, characterized in that, S2 specifically includes the following steps: S2.1 Add acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone and itaconic acid to deionized water and adjust the pH to 6-8; S2.

2. Add a free radical initiator under nitrogen protection and polymerize at 55-75℃ for 4-8 hours to obtain a high-temperature resistant multi-site complex polymer solution. S2.3 The polymer solution is subjected to precipitation, washing and drying to obtain the high-temperature resistant multi-site complex polymer.

7. The method for preparing the ultra-high temperature salt resistant composition for drilling fluid containing ketone derivatives according to claim 3, characterized in that, S3 specifically includes the following steps: S3.

1. Add the functionalized alkane-ketone recognition agent, high-temperature resistant multi-site complexing polymer, anti-interference ion modifier and rheology filtration stabilizer into the mixing equipment according to the formula; S3.2 Stir at 40-70℃ for 0.5-2 hours to obtain pre-dispersed compound material.

8. The method for preparing the ultra-high temperature salt resistant composition for drilling fluid containing ketone derivatives according to claim 7, characterized in that, S4 specifically includes the following steps: S4.

1. The pre-dispersed compound material is aged at 50-80℃ for 1-4 hours; S4.

2. The matured material is then spray-dried or vacuum-dried. S4.

3. The dried material is crushed and sieved to obtain the ultra-high temperature salt resistant composition for drilling fluid containing alkane derivatives.

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