Compound emulsifier as well as preparation method and application thereof

Abstract

The invention relates to the technical field of drilling fluid, in particular to a compound emulsifier as well as a preparation method and application thereof. The invention provides a compound emulsifier which comprises the following raw materials in parts by weight: 10-30 parts of an oleophylic component A, 15-30 parts of a hydrophilic component B, 10-30 parts of a wetting component C, 10-35 parts of a flow pattern adjusting component D and 35-50 parts of a cosolvent, the oleophylic component A is synthesized from organic acid I, organic amine and polybasic acid I; the hydrophilic component B is synthesized from the oleophylic component A, polybasic acid II and oxide; the wetting component C is synthesized by organic acid II and polyether polyamine; the flow pattern adjusting component D is generated by carrying out amidation reaction on tall oil containing abietic acid and branched polyethyleneimine. The composite emulsifier provided by the invention is an integrated emulsifier, and has the characteristics of emulsion stability, high demulsification voltage, good wettability and high temperature resistance.

Description

Technical Field

[0001] The invention relates to the technical field of drilling fluid, and in particular to a composite emulsifier and a preparation method and application thereof. Background Art

[0002] As the scale of shale oil and gas development expands, many problems have been found in the field application of oil-based / synthetic drilling fluids, such as large emulsifier loss, aggravated solid phase precipitation in drilling fluids due to untimely replenishment, and reduced emulsifier effectiveness due to temperature. The core of these problems is the temperature resistance of emulsifiers. Especially under high temperature and high density conditions, the problems of poor temperature resistance and aging resistance, difficult rheological adjustment, and large dosage are becoming more and more prominent, becoming a bottleneck for expanding the application of oil-based / synthetic drilling fluids and improving their benefits.

[0003] A lot of research has been conducted at home and abroad on oil-based drilling fluid emulsifiers, and great progress has been made. However, there are still many problems, such as harsh production conditions, changes in raw material components, high-temperature reactions, long time consumption, and complex processes, which lead to high costs and unstable performance. In terms of temperature resistance, it cannot fully meet the use of various complex working conditions, the replenishment amount is large, and the stabilization time is short, resulting in more complex situations underground. It is urgent to develop and produce cost-effective and stable temperature-resistant composite emulsifiers.

[0004] Patent CN104388062B discloses an emulsified wetting agent for high temperature resistant oil-based drilling fluid, its preparation method and application, which is mainly composed of fatty acid, N,N-bis(2-hydroxyethyl)ethylenediamine, alkylphenol polyoxyethylene ether and white oil. It solves the problems of reduced emulsification stability, abnormal rheology and barite precipitation of the drilling fluid system caused by high temperature decomposition of the emulsified wetting agent during drilling deep wells and ultra-deep wells. However, the group temperature resistance of alkylphenol polyoxyethylene ether is poor.

[0005] Patent CN103980869B discloses a method for preparing a solid emulsifier for oil-based drilling fluid, wherein an organic acid, diethylenetriamine, dicyclohexylcarbodiimide, and anhydride are reacted to generate a brown solid, which is crushed by a pulverizer to obtain a product. However, the process is relatively complicated and the raw materials are expensive.

[0006] Patent US6620770B1 uses fatty acids and rosin acid to react with diene affinity to prepare emulsifiers. Carboxylic acids, polycarboxylic acids, anhydrides, or mixed products thereof can be used. If maleic anhydride is used, fatty acid maleic anhydride modified products or rosin acid maleic anhydride modified products can be obtained. Unreacted fatty acids can be added to the added fatty acids to reduce their viscosity. Solid rosin acid adducts can be dissolved in fatty acids under heating. The addition degree of fatty acids and / or rosin acid is at least 40%. Polyamide carboxylic acids and modified fatty acids / rosin acids can be made into saponified products with lime, quicklime, or calcium chloride. However, due to the complex raw material components, the performance of batch products is unstable and cannot be used in occasions with demanding performance requirements. Summary of the invention

[0007] In order to solve the above problems in the prior art, the purpose of the present invention is to provide a composite emulsifier and its preparation method and application. The composite emulsifier in the present invention is a surfactant with multiple surface active groups that is artificially synthesized through molecular structure design, which can simultaneously play the role of emulsification and wetting in oil-based drilling fluid, and has stable performance and good temperature resistance, thereby improving the stability and temperature resistance of the entire oil-based drilling fluid system, simplifying the formula of the oil-based drilling fluid system, saving costs, and improving the benefits of exploration and development.

[0008] In a first aspect, the present invention provides a composite emulsifier, comprising the following raw materials by weight: 10 to 30 parts of a lipophilic component A, 15 to 30 parts of a hydrophilic component B, 10 to 30 parts of a wetting component C, 10 to 35 parts of a flow pattern regulating component D and 35 to 50 parts of a cosolvent;

[0009] The lipophilic component A is synthesized from organic acid I, organic amine and polyacid I;

[0010] The hydrophilic component B is synthesized from the lipophilic component A, polyacid II and oxide;

[0011] The wetting component C is synthesized from organic acid II and polyether polyamine;

[0012] The flow pattern regulating component D is prepared by amidation reaction of tall oil containing rosin acid and branched polyethyleneimine.

[0013] As a specific embodiment of the present invention, the synthesis step of oil component A includes:

[0014] The organic acid and the organic amine are mixed and vacuum dehydrated to obtain a mixture a, and then the polyacid I is added to the mixture a to synthesize the lipophilic component A.

[0015] Preferably, the conditions of vacuum dehydration I include: temperature of 150-200° C., time of 4-6 h;

[0016] Preferably, after the mixture a is cooled to 100-150° C., the polyacid I is added to the mixture a for reaction to synthesize the lipophilic component A.

[0017] Preferably, the reaction conditions of the mixture a and the polyacid I include: the reaction time is 2 to 4 hours.

[0018] As a specific embodiment of the present invention, the conditions for preparing component A include: the mass ratio of organic acid I, organic amine and polyacid I is (100-120):(10-50):(5-40).

[0019] As a specific embodiment of the present invention, the synthesis steps of the hydrophilic component B include: the lipophilic component A reacts with the polyacid II and the oxide to generate the hydrophilic component B;

[0020] Preferably, the reaction conditions of the lipophilic component A with the polyacid II and the oxide include: a temperature of 100 to 160° C. and a reaction time of 3 to 4 hours.

[0021] Preferably, the oxide is selected from one or more of calcium oxide, silicon dioxide, ferric oxide, aluminum oxide, magnesium oxide, copper oxide, and barium oxide.

[0022] As a specific embodiment of the present invention, the oxide is ordinary Portland cement. GB175-2007 stipulates that the hydraulic cementitious material made by grinding Portland cement clinker, 5% to 20% of mixed materials and an appropriate amount of gypsum is called ordinary Portland cement.

[0023] As a specific embodiment of the present invention, the conditions for preparing component B include: the mass ratio of lipophilic component A, polyacid II, and oxide is (100-140):(20-50):(20-50).

[0024] As a specific embodiment of the present invention, the wetting component C is prepared by mixing an organic acid II and a polyether polyamine and then vacuum dehydrating II.

[0025] Preferably, the conditions of vacuum dehydration II include: temperature of 150-200° C. and time of 6 to 8 hours.

[0026] Preferably, the mass ratio of organic acid II to polyether polyamine is (100-200):(150-40).

[0027] Specifically, the polyether polyamine in the present invention is prepared by amination of polyols, and the polyols include one or more of polyethylene glycol, polypropylene glycol and copolymers of ethylene glycol and propylene glycol.

[0028] Preferably, the polyether polyamine has a molecular weight of 230 to 5000.

[0029] As a specific embodiment of the present invention, the flow pattern regulating component D is prepared by amidation reaction of tall oil containing rosin acid and branched polyethyleneimine;

[0030] Preferably, the reaction conditions of the amidation reaction include: mixing tall oil containing rosin acid and branched polyethyleneimine, and vacuum dehydrating III to obtain;

[0031] Preferably, the conditions of vacuum dehydration III include: temperature of 100-180°C, time of 6-7h;

[0032] Preferably, the content of rosin acid in the tall oil is 20wt% to 40wt% of the mass of the tall oil;

[0033] Preferably, the molecular weight of the branched polyethyleneimine is 600 to 30,000;

[0034] Preferably, the mass ratio of the tall oil containing rosin acid to the polyethyleneimine is (100-120):(10-40).

[0035] As a specific embodiment of the present invention, the organic acid I is selected from one or more of tall oil acid, stearic acid, lauric acid, capric acid, palmitic acid, rosin acid, dodecylbenzenesulfonic acid, behenic acid, linolenic acid and adipic acid.

[0036] As a specific embodiment of the present invention, the organic acid II is selected from one or more of tall oil acid, stearic acid, lauric acid, capric acid, palmitic acid, rosin acid, dodecylbenzenesulfonic acid, behenic acid, linolenic acid and adipic acid.

[0037] As a specific embodiment of the present invention, the organic amine is selected from one or more of polyethylene polyamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine;

[0038] As a specific embodiment of the present invention, the polyacid I is selected from one or more of glutaric acid, adipic acid, lactic acid, citric acid, and maleic anhydride.

[0039] As a specific embodiment of the present invention, the polyacid II is selected from one or more of glutaric acid, adipic acid, lactic acid, citric acid, and maleic anhydride.

[0040] As a specific embodiment of the present invention, the co-solvent is selected from one or more of N-methylpyrrolidone, diethylene glycol butyl ether, hexamethylphosphinate triamide, hexaethylphosphinate triamide, and No. 3 white oil.

[0041] In a second aspect, the present invention provides a method for preparing a composite emulsifier provided in the first aspect of the present invention, comprising: mixing a lipophilic component A, a hydrophilic component B, a wetting component C and a flow pattern regulating component D to obtain a mixture b, and adding a co-solvent to the mixture b to prepare a composite emulsifier.

[0042] Preferably, after the mixture b is heated to 100-120° C., a cosolvent is added to the mixture b, and the mixture is cooled to room temperature to obtain a composite emulsifier.

[0043] In a third aspect, the present invention provides use of the composite emulsifier provided in the first aspect of the present invention and the composite emulsifier prepared by the preparation method provided in the second aspect of the present invention in drilling fluid.

[0044] As a specific embodiment of the present invention, the volume ratio of the composite emulsifier to the drilling fluid is 5% to 12%, preferably 6% to 8%. Specifically, the volume of the drilling fluid is calculated as the sum of the volume of the base oil and the volume of the calcium chloride aqueous solution.

[0045] Compared with the prior art, the present invention has the following beneficial effects.

[0046] (1) The composite emulsifier provided by the present invention is an integrated emulsifier. Due to the introduction of polyether polyamine and branched polyethyleneimine, the molecular weight of the emulsifier is increased, and the polyacid further makes the emulsifier molecules moderately cross-linked. The excess polyacid increases the wettability of the emulsifier and cooperates with the lipophilic group to facilitate the emulsifier to form a film with higher strength at the oil-water interface. The emulsifier has higher stability and temperature resistance.

[0047] (2) The composite emulsifier for oil-based drilling fluid provided by the present invention has the properties of both lipophilic emulsifier and hydrophilic emulsifier, thus overcoming the defect that the previous emulsifier products must be used in combination with a main emulsifier and an auxiliary emulsifier, and can reduce the number of times and amount of emulsifier added to the drilling fluid, thereby reducing the cost of the drilling fluid.

[0048] (3) The composite emulsifier for the oil-based drilling fluid provided by the present invention contains a carboxylic acid group and a relatively high molecular weight, so that the emulsifier has a wetting and shearing effect, and there is no need to use an additional wetting agent in the oil-based drilling fluid.

[0049] (4) The composite emulsifier for oil-based drilling fluid provided by the present invention has a simple preparation process, convenient operation, low cost and stable product quality. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with specific embodiments, but they do not constitute any limitation to the present invention.

[0051] Example 1

[0052] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by mass, includes 10g of oleophilic component A, 20g of hydrophilic component B, 25g of wetting component C, 10g of flow pattern regulating component D and 35g of cosolvent. The four components A, B, C and D are mixed and heated to 100°C to melt, and then stirred, 35g of cosolvent is added dropwise, stirred for 5 minutes, and cooled to room temperature to obtain 100g of dark brown composite emulsifier 1.

[0053] Among them, the preparation of component A: first add 120g of tall oil acid to a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, start stirring, then drop 20g of tetraethylenepentamine, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 4 hours, and generate about 5mL of water. After stopping the vacuum, wait until it cools to 100°C, and add 10g of citric acid in batches under stirring. After all the citric acid is added, heat the reaction container to 140°C, maintain the vacuum reaction for 3 hours, generate about 2.2mL of water, and cool to room temperature to obtain about 140g of component A.

[0054] Preparation of component B: Use the same reaction container as the preparation process of component A, take 70g of component A, put it in the reaction container, start stirring, drop 10g of lactic acid, slowly raise the temperature to 150°C, sprinkle 10g of calcium oxide powder, stir and maintain the temperature, generate about 2mL of water, vacuum react for 4 hours, and obtain about 85g of component B.

[0055] Preparation of component C: Using the same reaction vessel as component A, add 100 g of tall oil acid and 50 g of polyether polyamine (molecular weight 240) into the reaction vessel, slowly raise the temperature to 180°C, evacuate the condenser, maintain the reaction for 7 hours, generate about 4 mL of water, and cool to room temperature to obtain component C.

[0056] Preparation of component D: Using the same reaction vessel as component A, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 600) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.5 mL of water, and cool to room temperature to obtain component D.

[0057] The co-solvent is No. 3 white oil.

[0058] Example 2

[0059] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by mass, includes 20g of oleophilic component A, 15g of hydrophilic component B, 20g of wetting component C, 10g of flow pattern regulating component D and 35g of cosolvent. After the four components A, B, C and D are mixed and heated to 100°C to melt, stirring is started, 35g of cosolvent is added dropwise, stirred for 5 minutes, and cooled to room temperature to obtain 100g of dark brown composite emulsifier 2.

[0060] Among them, the preparation of component A: In a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, first add 120g of palmitic acid, start stirring, then drop 25g of polyethylene polyamine, slowly heat to 190°C, evacuate from the condenser, maintain the reaction for 5 hours, and generate about 8mL of water. After stopping the vacuum, wait to cool to 100°C, and add 10g of maleic anhydride in batches under stirring. After all the maleic anhydride is added, heat to 140°C, maintain vacuum reaction for 3 hours, generate about 0.5mL of water, and cool to room temperature to obtain about 145g of component A.

[0061] Preparation of component B: Use the same reaction container as component A, take 70 g of component A, place it in the reaction container, start stirring, sprinkle 12 g of maleic anhydride in portions, slowly raise the temperature to 150°C, sprinkle 15 g of ferric oxide powder, stir and maintain the temperature, generate about 1 mL of water, evacuate the reaction for 4 hours, and obtain about 95 g of component B.

[0062] Preparation of component C: Use the same reaction container as component A in the preparation process, add 100 g of palmitic acid and 50 g of polyether polyamine (molecular weight 3500) into the reaction container, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 6 hours, generate about 6 mL of water, and cool to room temperature to obtain component C.

[0063] Preparation of component D: Using the same reaction vessel as component A, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 4300) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.6 mL of water, and cool to room temperature to obtain component D.

[0064] The cosolvent is N-methylpyrrolidone.

[0065] Example 3

[0066] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by mass, includes 10g of oleophilic component A, 30g of hydrophilic component B, 10g of wetting component C, 10g of flow pattern regulating component D and 40g of cosolvent. After the four components A, B, C and D are mixed and heated to 100°C to melt, stirring is started, 40g of cosolvent is dripped in, stirred for 5 minutes, and cooled to room temperature to obtain 100g of dark brown composite emulsifier 3.

[0067] Among them, the preparation of component A: In a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, first add 120g of palmitic acid, start stirring, then drop 25g of polyethylene polyamine, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 5 hours, and generate about 8.1mL of water. After stopping the vacuum, wait until it cools to 100°C, and add 12g of maleic anhydride in batches under stirring. After all the maleic anhydride is added, heat to 150°C, maintain the vacuum reaction for 3 hours, generate about 0.5mL of water, and cool to room temperature to obtain about 146g of component A.

[0068] Preparation of component B: Use the same reaction container as component A in the preparation process, take 70g of component A, place it in the reaction container, start stirring, add 12g of maleic anhydride in portions, slowly heat to 150°C, sprinkle in 15g of ordinary Portland cement, stir and maintain the temperature, generate about 1mL of water, vacuum react for 3 hours, and obtain about 90g of component B.

[0069] Preparation of component C: Use the same reaction container as component A in the preparation process, add 100 g of palmitic acid and 40 g of polyether polyamine (molecular weight 3500) into the reaction container, slowly heat to 190°C, evacuate from the condenser, maintain the reaction for 7 hours, generate about 6 mL of water, and cool to room temperature to obtain component C.

[0070] Preparation of component D: Using the same reaction vessel as component A, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 4300) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.6 mL of water, and cool to room temperature to obtain component D.

[0071] The co-solvent is No. 3 white oil.

[0072] Comparative Example 1

[0073] A composite emulsifier for temperature-resistant oil-based drilling fluid includes, by weight, 30 g of a hydrophilic component B, 10 g of a wetting component C, 10 g of a flow pattern regulating component D, and 40 g of a cosolvent. After the three components B, C, and D are mixed and heated to 100° C. to melt, stirring is started, 40 g of the cosolvent is dripped in, stirred for 5 minutes, and cooled to room temperature to obtain a comparative composite emulsifier 1.

[0074] Among them, the preparation of component B: use a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, take 70g of component A, put it in the reaction container, start stirring, add 12g of maleic anhydride in portions, slowly heat to 150°C, sprinkle in 15g of ordinary Portland cement, stir and maintain the temperature, generate about 1mL of water, vacuum react for 3 hours, and obtain about 90g of component B.

[0075] Preparation of component C: Use the same reaction container as component B in the preparation process, add 100 g of palmitic acid and 40 g of polyether polyamine (molecular weight 3500) into the reaction container, slowly heat to 190°C, evacuate from the condenser, maintain the reaction for 7 hours, generate about 6 mL of water, and cool to room temperature to obtain component C.

[0076] Preparation of component D: Using the same reaction vessel as component B, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 4300) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.6 mL of water, and cool to room temperature to obtain component D.

[0077] The co-solvent is No. 3 white oil.

[0078] Comparative Example 2

[0079] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by weight, includes 10g of oleophilic component A, 10g of wetting component C, 10g of flow pattern regulating component D and 40g of cosolvent. After the three components A, C and D are mixed and heated to 100°C to melt, stirring is started, 40g of cosolvent is dripped into it, stirred for 5 minutes, and cooled to room temperature to obtain comparative composite emulsifier 2.

[0080] Among them, the preparation of component A: In a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, first add 120g of palmitic acid, start stirring, then drop 25g of polyethylene polyamine, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 5 hours, and generate about 8.1mL of water. After stopping the vacuum, wait until it cools to 100°C, and add 12g of maleic anhydride in batches under stirring. After all the maleic anhydride is added, heat to 150°C, maintain the vacuum reaction for 3 hours, generate about 0.5mL of water, and cool to room temperature to obtain about 146g of component A.

[0081] Preparation of component C: Use the same reaction vessel as component A, add 100 g of palmitic acid and 40 g of polyether polyamine (molecular weight 3500) into the reaction vessel, slowly heat to 190°C, evacuate the condenser, maintain the reaction for 7 hours, generate about 6 mL of water, and cool to room temperature to obtain component C.

[0082] Preparation of component D: Using the same reaction vessel as component A, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 4300) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.6 mL of water, and cool to room temperature to obtain component D.

[0083] The co-solvent is No. 3 white oil.

[0084] Comparative Example 3

[0085] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by weight, includes 10g of oleophilic component A, 30g of hydrophilic component B, 10g of flow pattern regulating component D and 40g of cosolvent. After the three components A, B and D are mixed and heated to 100°C to melt, stirring is started, 40g of cosolvent is dripped in, stirred for 5 minutes, and cooled to room temperature, to obtain comparative composite emulsifier 3.

[0086] Among them, the preparation of component A: In a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, first add 120g of palmitic acid, start stirring, then drop 25g of polyethylene polyamine, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 5 hours, and generate about 8.1mL of water. After stopping the vacuum, wait until it cools to 100°C, and add 12g of maleic anhydride in batches under stirring. After all the maleic anhydride is added, heat to 150°C, maintain the vacuum reaction for 3 hours, generate about 0.5mL of water, and cool to room temperature to obtain about 146g of component A.

[0087] Preparation of component B: Use the same reaction container as component A in the preparation process, take 70 g of component A, place it in the reactor, start stirring, add 12 g of maleic anhydride in portions, slowly heat to 150°C, sprinkle in 15 g of ordinary Portland cement, stir and maintain the temperature, generate about 1 mL of water, vacuum react for 3 hours, and obtain about 90 g of component B.

[0088] Preparation of component D: Using the same reaction vessel as component A, add 100 g of refined tall oil (containing 40 wt% of rosin acid) and 40 g of branched polyethyleneimine (molecular weight 4300) into the reaction vessel, slowly heat to 170° C., maintain the reaction for 6 hours, generate about 3.6 mL of water, and cool to room temperature to obtain component D.

[0089] The co-solvent is No. 3 white oil.

[0090] Comparative Example 4

[0091] A composite emulsifier for temperature-resistant oil-based drilling fluid, calculated by weight, includes 10g of oleophilic component A, 30g of hydrophilic component B, 10g of wetting component C and 40g of cosolvent. After the three components A, B and C are mixed and heated to 100°C to melt, stirring is started, 40g of cosolvent is dripped in, stirred for 5 minutes, and cooled to room temperature, to obtain comparative composite emulsifier 4.

[0092] Among them, the preparation of component A: In a three-necked flask reaction container equipped with a stirrer, a reflux condenser and a dropping funnel, first add 120g of palmitic acid, start stirring, then drop 25g of polyethylene polyamine, slowly heat to 180°C, evacuate from the condenser, maintain the reaction for 5 hours, and generate about 8.1mL of water. After stopping the vacuum, wait until it cools to 100°C, and add 12g of maleic anhydride in batches under stirring. After all the maleic anhydride is added, heat to 150°C, maintain the vacuum reaction for 3 hours, generate about 0.5mL of water, and cool to room temperature to obtain about 146g of component A.

[0093] Preparation of component B: Use the same reaction container as component A in the preparation process, take 70 g of component A, place it in the reactor, start stirring, add 12 g of maleic anhydride in portions, slowly heat to 150°C, sprinkle in 15 g of ordinary Portland cement, stir and maintain the temperature, generate about 1 mL of water, vacuum react for 3 hours, and obtain about 90 g of component B.

[0094] Preparation of component C: Use the same reaction container as component A to add 100 g of palmitic acid and 40 g of polyether polyamine (molecular weight 3500) into the reaction container, slowly heat to 190°C, evacuate the condenser, maintain the reaction for 7 hours, generate about 6 mL of water, and cool to room temperature to obtain component C.

[0095] The co-solvent is No. 3 white oil.

[0096] Comparative Example 5

[0097] The emulsifier in Comparative Example 5 includes a primary emulsifier, an auxiliary emulsifier and a wetting agent. The primary emulsifier is SMEMUL-1, the auxiliary emulsifier is SMEMUL-2, and the wetting agent is TC-WET.

[0098] Performance Testing

[0099] The performance of the composite emulsifier prepared in each embodiment and comparative example was tested.

[0100] Drilling fluid formula: 240mL base oil (No. 5 white oil) + 4% primary emulsifier + 4% auxiliary emulsifier + 4% wetting agent + 2.5% organic soil + 3% calcium oxide + 5% oxidized asphalt + 60mL calcium chloride aqueous solution (the mass volume ratio of calcium chloride in the calcium chloride aqueous solution is 25%) + 600g barite (the formula density is 1.90g / cm 3 ). The percentage of the primary emulsifier, auxiliary emulsifier, wetting agent, organic soil, calcium oxide and oxidized asphalt added to the drilling fluid formula is the mass volume ratio, and the volume of the drilling fluid is based on 300mL. For example, 4% of the primary emulsifier is the percentage of the mass of the primary emulsifier to the volume of the drilling fluid (300mL).

[0101] In Table 1, the emulsifiers in the composite emulsifiers 1-3, comparative composite emulsifiers 1-4, and comparative example 5 replace 4% of the primary emulsifier, 4% of the auxiliary emulsifier, and 4% of the wetting agent in the drilling fluid formula; the addition amount of the composite emulsifiers 1-3 and comparative composite emulsifiers 1-4 is a mass volume ratio, and the volume is based on 300 mL. For example, 12% of the composite emulsifier 1 means that 4% of the primary emulsifier, 4% of the auxiliary emulsifier, and 4% of the wetting agent in the drilling fluid formula are replaced by 12% of the composite emulsifier 1.

[0102] The samples to be tested were aged by rolling at 200℃ for 16h. At 65℃, the demulsification voltage before and after aging was measured using an electric stability meter, the plastic viscosity, dynamic shear force and static shear force before and after aging were measured using a six-speed viscometer, and the settlement after aging was tested using a steel ruler sedimentation instrument. The test results are shown in Table 1.

[0103] Table 1 Test data of oil-based drilling fluid emulsifiers in Examples and Comparative Examples

[0104]

[0105]

[0106] As shown in Table 1, compared with Comparative Example 5, with the addition of 12% emulsifier, the demulsification voltage before and after aging in Example 1 and Example 2 is higher than that in Comparative Example 5. Compared with the emulsifier in Comparative Example 5, the composite emulsifier prepared by Example 2 and Example 3 has the characteristics of low total dosage under the corresponding temperature and density conditions. When the total amount of composite emulsifier is 8%, the performance of the commercial emulsifier (emulsifier in Comparative Example 5) at 12% dosage can be achieved. In particular, the composite emulsifier formed in Example 3 is synthesized by replacing oxides with ordinary noble cement, and has a lower dosage. Under the condition of 6% emulsifier addition, the demulsification voltage of Example 3 before and after aging is higher than that of Comparative Example 5. Therefore, the composite emulsifier of the present invention can significantly reduce the total dosage of the treatment agent, reduce the cost of drilling fluid, reduce the number of agents, and simplify the construction process.

[0107] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A composite emulsifier, characterized in that: The invention comprises the following raw materials in weight fractions: 10 to 30 parts of lipophilic component A, 15 to 30 parts of hydrophilic component B, 10 to 30 parts of wetting component C, 10 to 35 parts of flow pattern regulating component D and 35 to 50 parts of cosolvent; The lipophilic component A is synthesized from an organic acid I, an organic amine and a polyacid I; The hydrophilic component B is synthesized from the lipophilic component A, polyacid II and oxide; The wetting component C is synthesized from organic acid II and polyether polyamine; The flow pattern regulating component D is produced by amidation reaction of tall oil containing rosin acid and branched polyethyleneimine.

2. The composite emulsifier according to claim 1, characterized in that The synthesis steps of the lipophilic component A include: The organic acid and the organic amine are mixed and then vacuum-dehydrated to obtain a mixture a, and a polyacid I is added to the mixture a to synthesize a lipophilic component A; Preferably, the conditions of vacuum dehydration I include: temperature of 150-200° C., time of 4-6 h; Preferably, after the mixture a is cooled to 100-150° C., a polyacid I is added to the mixture a to react and synthesize a lipophilic component A; Preferably, the reaction conditions of the mixture a and the polyacid I include: the reaction time is 2 to 4 hours.

3. The composite emulsifier according to claim 2, characterized in that The conditions for preparing component A include that the mass ratio of organic acid I, organic amine and polyacid I is (100-120):(10-50):(5-40).

4. The composite emulsifier according to claim 3, characterized in that The synthesis step of the hydrophilic component B comprises: the lipophilic component A reacts with the polyacid II and the oxide to generate the hydrophilic component B; Preferably, the reaction conditions of the lipophilic component A, the polyacid II and the oxide include: a temperature of 100 to 160° C., a reaction time of 3 to 4 h; Preferably, the oxide is selected from one or more of calcium oxide, silicon dioxide, ferric oxide, aluminum oxide, magnesium oxide, copper oxide, and barium oxide; And / or, the oxide is ordinary Portland cement.

5. The composite emulsifier according to claim 4, characterized in that The conditions for preparing component B include: the mass ratio of lipophilic component A, polyacid II, and oxide is (100-140):(20-50):(20-50).

6. The composite emulsifier according to claim 5, characterized in that Wetting component C is prepared by mixing organic acid II and polyether polyamine and then vacuum dehydrating II; Preferably, the conditions of vacuum dehydration II include: temperature of 150-200° C., time of 6-8 h; Preferably, the mass ratio of organic acid II to polyether polyamine is (100-200):(150-40); Preferably, the molecular weight of the polyether polyamine is 230-5000.

7. The composite emulsifier according to claim 6, characterized in that The flow pattern regulating component D is prepared by amidation reaction of tall oil containing rosin acid and branched polyethyleneimine; Preferably, the reaction conditions of the amidation reaction include: mixing tall oil containing rosin acid and branched polyethyleneimine, and vacuum dehydrating III to obtain; Preferably, the conditions of vacuum dehydration III include: temperature of 100-180°C, time of 6-7h; Preferably, the content of rosin acid in the tall oil is 20 wt% to 40 wt% of the tall oil; Preferably, the molecular weight of the branched polyethyleneimine is 600 to 30,000; Preferably, the mass ratio of the tall oil containing rosin acid to the polyethyleneimine is (100-120):(10-40).

8. The composite emulsifier according to any one of claims 1 to 7, characterized in that The organic acid I is selected from one or more of tall oil acid, stearic acid, lauric acid, capric acid, palmitic acid, rosin acid, dodecylbenzenesulfonic acid, behenic acid, linolenic acid and adipic acid; and / or, the organic acid II is selected from one or more of tall oil acid, stearic acid, lauric acid, capric acid, palmitic acid, rosin acid, dodecylbenzenesulfonic acid, behenic acid, linolenic acid and adipic acid; And / or, the organic amine is one or more selected from polyethylene polyamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine; And / or, the polyacid I is selected from one or more of glutaric acid, adipic acid, lactic acid, citric acid, and maleic anhydride; And / or, the polyacid II is selected from one or more of glutaric acid, adipic acid, lactic acid, citric acid, and maleic anhydride.

9. The composite emulsifier according to any one of claims 1 to 8, characterized in that The co-solvent is selected from one or more of N-methylpyrrolidone, diethylene glycol butyl ether, hexamethylphosphinyl triamide, hexaethylphosphinyl triamide, and No. 3 white oil.

10. A method for preparing the composite emulsifier according to any one of claims 1 to 9, characterized in that: The lipophilic component A, the hydrophilic component B, the wetting component C and the flow pattern regulating component D are mixed to obtain a mixture b, and a cosolvent is added to the mixture b to prepare the composite emulsifier; Preferably, after the mixture b is heated to 100-120° C., a cosolvent is added to the mixture b, and the mixture is cooled to room temperature to obtain the composite emulsifier.

11. Use of the composite emulsifier according to any one of claims 1 to 9 or the composite emulsifier prepared by the preparation method according to claim 10 in drilling fluid.

12. The use according to claim 11, characterized in that: The volume ratio of the composite emulsifier to the drilling fluid is 5% to 12%, preferably 6% to 8%.

Images