RU2336291C1 - Emulsifing and stabilising agent for invert emulsions and method of preparation of invert emulsion drill mud on its basis - Google Patents

Abstract

FIELD: oil and gas production industry.

SUBSTANCE: inventions are related to area of oil and gas well drilling. Emulsifing and stabilising agent of invert emulsions contain the following wt %: derivative of tallow oil on the basis of higher fatty acids 6.2-22.0; potassic alkaline agent 4.2-13.5; water 4.5-14.6; dissolvent - non-aromatic claroline - other. Method of preparation of invert emulsion drill mud that includes preparation of pleofil-based mud by introduction of emulsifing and stabilising agent to hydrocarbon reactant at weight ratio (1.5-9):1 correspondingly preparation of water-based mud as mixture of water solution of calcium chloride that ensures minimum concentration of calcium ions in water phase of resulted emulsion 11.6 g/l and water solution of caustic magnesite with concentration 16-120 g/l, their mixture by introducing water-based mud to oleofil-based mud at the following ratio of ingredients, wt %: emulsifier 5-20; hydrocarbon reactant 20-88; calcium chloride 2-3; caustic magnesite 1-3; fresh or salt water - other. Invention is developed in subclaims.

EFFECT: maintenance of pay bed reservoir properties.

9 cl, 4 tbl

Description

The invention relates to the field of drilling oil and gas wells, in particular to emulsifiers of invert emulsion drilling fluids, as well as to a method for preparing with its use an invert emulsion drilling fluid used primarily for drilling oil and gas wells with a very curved wellbore, wells with large laying and horizontal wells, as well as for opening productive formations and killing wells.

The configuration of the wellbore of highly curved and horizontal wells contributes to the deposition of drill cuttings particles on the bottom wall of the well. In this regard, the rheological properties of the used drilling fluids, which ensure the retention and removal of cuttings from the well bore, are of particular importance when drilling this type of well.

When drilling highly curved and horizontal wells, higher demands are placed on tribological, inhibitory and filtration performance of drilling fluids.

The type of these solutions for drilling highly curved wells is selected on the basis of the need to solve the problem associated with overcoming the frictional forces, which increase as the angle of inclination increases. The choice of hydrocarbon-based drilling fluids for drilling highly curved and horizontal wells is primarily due to the fact that they provide a significant reduction in the friction forces of the tool on the well walls compared to water-based fluids.

At the same time, the low efficiency of many currently developed hydrocarbon-based drilling fluids for drilling highly curved wells is due to their insufficiently high rheological properties at low shear rates.

Particular requirements for the development and use of invert emulsion drilling fluids are imposed on the emulsifying base of these fluids, which is responsible for the process of emulsification of two immiscible fluids and imparting properties of “true” hydrocarbon fluids to such systems. Traditionally, the improvement of the quality of invert emulsion drilling fluids is achieved by the use of a large number of special reagents: emulsifiers, stabilizers, water repellents, filtration reducers, because most industrial reagents designed for emulsification of water in an oleophilic liquid do not have the whole range of necessary qualities. This reduces the manufacturability of the preparation of invert solutions, complicates the composition and management of their properties.

Known emulsifier of invert emulsion drilling fluids "Emultal", which is a product of the interaction of fatty acids - oleic, linoleic, linolenic and resin acids that are part of tall oil, with polyhydric alcohol triethanolamine (Tolkunov V.I., Kheifets IB Hydrophobno -emulsion drilling fluids. M: Nedra. - 1983. - 167 p.). The specified emulsifier is obtained by heating the mixture at a temperature of 155-165 ° C for 16 hours and normal pressure. As a result of the interaction of mainly unsaturated normal fatty acids of the C ₈ -C ₂₄ fraction included in the composition of tall oil with triethanolamine, an esterification reaction proceeds with the formation of a mixture of tall oil fatty acid triethanolamine esters.

The disadvantages of Emultal include its low emulsifying and stabilizing ability with respect to hydrophobic liquids with a low content of aromatic hydrocarbons, including oils of vegetable and animal origin and synthetic liquids based on polyalphaolefins, polyalkylene glycols, etc., which are currently the basis "Oil" phase of environmentally friendly invert emulsion drilling fluids.

Also obtained on its basis invert emulsions have high values of the index filtration (40 cm ^3/30 min at a pressure drop of 0.1 MPa), unsatisfactory for drilling horizontal wells and sloping rheological parameters, insufficient aggregative and sedimentation stability.

In addition, the heterogeneity and inconstancy of the Emulsifier emulsifier associated with the nature of the feedstock (tall oil of deciduous or coniferous species) adversely affects the performance of both the emulsifier itself and the properties of invert emulsions based on it.

Also known is an emulsifier-stabilizer of hydrophobic-emulsion drilling fluids of the following composition: a mixture of bottoms production of fatty acids and triethanolamine - 57.9-85.0; the solvent is 15.0-42.1, moreover, diesel fuel or kerosene is used as the solvent (RF Patent No. 2201950, class C09K 7/06, publ. 04.10.2002). The specified emulsifier has a complex effect, namely, it is emulsifying and stabilizing at the same time, which is expressed in high heat resistance and aggregative stability of hydrophobic-emulsion drilling fluids obtained on its basis

An emulsifier-stabilizer of hydrophobic-emulsion drilling fluids is obtained by heating and mixing at atmospheric pressure of fatty acids mixed with triethanolamine, while the residue of the production of synthetic fatty acids in the ratio with triethanolamine 5: 1 is used as fatty acids, and heating is carried out at a temperature of 120 -150 ° C for 4-8 hours in a solvent environment.

The disadvantages of the known emulsifier-stabilizer include low thixotropic properties of hydrophobic-emulsion drilling fluids obtained on its basis (static shear stress CHC _1/10 is 0.3-7.5 / 0.5-9.2 dPa), high values of the filtration rate F even with a small pressure drop of 0.1 MPa (P = 18-32 cm ^3/30 min), large time required for operations related to heating and dissolving said emulsifier components (the reaction time is 4-8 hours at 120-150 ° C), and, as a consequence, the complexity of these operas tion in fishing conditions.

Closest to the proposed stabilizer emulsifier in technical essence is the invert emulsion emulsifier Neftenol NZ (RF Patent No. 2200056, class C09K 7/06, publ. 03.10.2003), which contains the following ingredients, wt.%: Oil-soluble surface -active substance (Emultal or emulsifier base Neftenol NZ) - 20-40; additives (calcium chloride - 1-3.4; water - 2.0-6.8; modified bentonite - 3.6-10.8); hydrocarbon solvent - up to 100. As an oil-soluble surfactant, the emulsifier contains an ester - the product of the interaction of tall oil fatty acids and triethanolamine (Emultal) or a mixture of tall oil acid esters and triethanolamine with tall oil acid esters and ethoxylated alkylamine (the base of the Neftenol emulsifier NZ). As a hydrocarbon solvent, low-hardening fractions of a petroleum-aromatic base, commodity medium distillate fuels or light oils (arctic diesel fuel, jet fuel, etc.) are used. As additives that improve the stabilizing and emulsifying properties of the emulsions obtained, calcium chloride, organobentonite and water are used.

The disadvantage of this known emulsifier is that the invert emulsion drilling fluids obtained on its basis are characterized by insufficiently high rheological and thixotropic properties, and unsatisfactory filtration indicators, which does not allow their use for drilling shallow wells with a large laying and horizontal wells.

In addition, the specified well-known emulsifier contains a high colloidal solid phase (bentonite), the presence of which in the composition of the emulsion drilling fluid can have a negative (irreversibly colmatizing) effect on the opened reservoir.

In addition, as a hydrocarbon solvent in the known emulsifier, petroleum products processing products containing aromatic compounds are used, which increases the environmental hazard of this reagent.

In addition to the above, it is proposed to use oil and its refined products (diesel fuel), which have a very negative impact on the environment, as the hydrocarbon base of invert emulsions obtained using a well-known emulsifier.

A known method of producing invert emulsion drilling fluid (Auth. Certificate of the USSR No. 1134594, class C09K 7/06, publ. 1980), which consists in the following. In a water-based clay solution containing not more than 10 wt.% Clay, tall pitch, saponified with sodium carbonate (50 wt.% Of the calculated amount) is dissolved with continuous stirring (circulation). Then, diesel fuel is introduced with the remaining part of tall oil pitch dissolved in it. PPF reagent (a by-product of phytosterol production) and finely divided chalk are added to the resulting emulsion.

The disadvantage of this method is the increased consumption of saponified tall oil pitch (10-12 wt.%), Due to the fact that sodium carboxylic acid soaps are stabilizers mainly water-oil emulsions, and, as a result, the water content of the resulting drilling fluid in this method is limited to 23-39 wt. .%.

In addition, the disadvantage of emulsion drilling fluids obtained by the known method is the low values of rheological parameters (plastic viscosity - 14-18 cP, dynamic shear stress CSN - 28-68 dPa), which do not provide complete removal of drill cuttings from shallow and horizontal sections of the wellbore.

Also known is a method of preparing a hydrophobic emulsion drilling fluid (RF Patent No. 2238297, class C09K 7/06, publ. 2000), according to which a uniform feed is carried out with vigorous stirring until the required process parameters are obtained in diesel fuel or polymer clay oil ( as a polymer, carboxymethyl cellulose) and a 20% aqueous solution of carbolignosulfonate, while the supply of the specified solution of carbolignosulfonate pitch and polymer clay water-based solution is lyayut simultaneously. Obtained by a known method invert-emulsion drilling fluid on a mixed water-hydrocarbon basis is designed to ensure complete removal of sludge in sections of the wellbore with an zenith angle of more than 60 degrees and is characterized by the following structural and rheological properties: plastic viscosity 23-36 MPa · s; CSN 155-305 dPa; SNA 66-81 / 84-165 dPa.

The disadvantage of the invert emulsion drilling fluid obtained by the specified known method is the high consistency coefficient "K", which leads to the emergence of high hydraulic resistances during the flow of the drilling fluid and, as a result, adversely affects the efficiency of transfer of hydraulic power to the downhole motor and bit .

In addition, the emulsion solution obtained by the known method contains a sufficiently large amount of clay, which negatively affects the filtration-capacitive properties of the bottom-hole zone of the reservoir due to the irreversible mudding of the porous collector by clay.

Serious disadvantages also include the fact that it is proposed to use oil or diesel fuel as the hydrocarbon phase in the known method, which in their physicochemical and toxicological characteristics are fire and environmentally hazardous substances that are prohibited for use in areas with the status of specially protected territories.

Closest to the proposed technical solution is a method of producing invert emulsion drilling fluids described in the example of the invention according to the RF Patent No. 2200056, class. S09K 7/06, publ. 1999. The essence of the known method is as follows. A solution is prepared on an oleophilic basis by introducing invert emulsions (Emultal or Neftenol NZ) into a hydrocarbon solvent heated to 60 ° C with stirring. Further, without stopping mixing, add organobentonite (3.6-10.8%) and a water-based solution - an aqueous solution of calcium chloride. Then, without stopping mixing, first the calculated amount of diesel fuel and oil (20%) is introduced into the mixture, then the calculated amount of produced water (76%), after mixing the mixture for 15-20 minutes, an invert-emulsion drilling water-type mud is obtained oil. "

The disadvantages of this preparation method include the insufficiently high structural and rheological properties of drilling fluids obtained by the known method (plastic viscosity when using diesel fuel as a hydrocarbon phase is 21 mPa · s, CSN is 42 dPa), and also relatively high for invert emulsions ( i.e., for a drilling fluid), a filtration rate (Ф _{0.1 mPa} = 5 cm ³ ), which does not allow us to recommend the invert emulsion drilling fluids obtained by this method for flat and subhorizontal drilling ny wells. Lower values of the filtration rate and higher values of the rheological properties of the known method using a known emulsifier were obtained only when using oil as an oleophilic phase.

A single technical result achieved in the implementation of the claimed group of inventions is to obtain using the proposed emulsifier-stabilizer invert emulsion drilling fluids intended for drilling predominantly flat and horizontal wells, with the necessary rheological, thixotropic, pseudo-plastic and filtration properties, low consistency, and also with the ability to preserve the reservoir properties of reservoirs due to low values of p filtering agent and the absence of a clay phase, while simplifying the ingredient composition of the emulsifier-stabilizer used for its preparation and cooking technology.

The specified technical result is achieved by the proposed invert emulsifier-stabilizer emulsifier, including an oil-soluble surfactant surfactant, a mineral additive, water and a solvent, while the new one is that as an oil-soluble surfactant, said emulsifier contains tall oil processing product based on higher fatty acids, as a mineral additive - potassium alkaline reagent, and as a solvent - non-aromatic light mineral oil, in the following ratio ingre diet, wt.%:

Tall oil processing product based on higher fatty acids 6.2-22.0 Potassium alkaline reagent 4.2-13.5 Water 4,5-14,6 Solvent - non-aromatic lung mineral oil rest

The emulsifier may further comprise caustic magnesite.

As a product of the processing of tall oil based on higher fatty acids, the emulsifier contains tall oil fatty acids, or distilled tall oil, or light tall oil.

As a non-aromatic light mineral oil, the emulsifier contains industrial or transformer oil.

As a potassium alkaline reagent, the emulsifier contains potassium hydroxide or potassium carbonate.

The mechanism of emulsifying-stabilizing action of the inventive emulsifier-stabilizer in the preparation of invert emulsion drilling fluids is as follows.

Tall oil products based on higher fatty acids, which in their composition belong to aliphatic carboxylic acids with a chain length of mainly C ₁₅ -C ₁₇ , in reaction with an alkaline reagent represented by potassium hydroxide, form potassium soap, which, due to its liquid aggregate the state is uniformly distributed in the solvent, forming a colloidal surfactant solution, which provides a low surface tension at the interface with the aqueous phase and can form on the interfacial surface Strong protective films.

When interacting with water, caustic magnesite partially forms a hydrogel, which, like magnesite itself, is poorly soluble in water, and therefore concentrates on the interface, acting as a builder.

The specified technical result is achieved by the fact that in the known method of preparing an invert emulsion drilling fluid, which includes preparing an oleophilic based solution by introducing an invert emulsion stabilizer emulsifier-stabilizer into a hydrocarbon reagent, preparing a water based solution, mixing them together by introducing a water based solution into the solution based on oleophilic, while the new is that as a solution based on oleophilic based prepare a mixture of a hydrocarbon reagent with the specified e by an ulcer at their mass ratio (1.5–9): 1, respectively, as a water-based solution, a mixture of an aqueous solution of calcium chloride is prepared, which provides a concentration of calcium ions in the aqueous phase of the resulting emulsion of at least 11.6 g / l and an aqueous solution caustic magnesite with a concentration of 16-120 g / l, and the starting ingredients are taken in the following ratio, wt.%:

Emulsifier 5-20 Hydrocarbon reagent 20-88 Calcium chloride 2-3 Caustic Magnesite 1-3 Fresh or mineralized water rest.

In the invert emulsion drilling mud, an additional higher fatty unsaturated acid is added — oleic or linoleic or α-linolenic acid in an amount of 0.5-2% by weight.

Mineral oils, or lubricating additives for drilling fluids based on vegetable oils, or esters of vegetable oils, or synthetic fluids from the class of polyalphaolefins, polyalkylene glycols are used as a hydrocarbon reagent.

The water-based solution is divided into two portions in a volume ratio of 9: 1, which are introduced sequentially into the oleophilic-based solution and the resulting mixture is mixed after each portion is added for at least 1 hour.

The technical result is provided due to the following.

The mechanism of the occurrence of intermolecular chemical, intermediate and physical interactions in the system "hydrocarbon reagent - emulsifier-stabilizer - an aqueous solution of calcium chloride and caustic magnesite" is as follows. Due to the correctly selected composition of the ingredients and the proposed method of introducing them into the specified system, at the stage of emulsification of the aqueous phase in the oleophilic (hydrophobic) liquid, the formation of the primary stabilizer of the system and the secondary stabilizer proceed in parallel, which together prevent the coalescence of droplets of the dispersed phase, hydrophobizing the surface of the solid phase and reducing filtration loss of the resulting emulsion - invert emulsion drilling mud.

The primary stabilizer of the said system is the calcium and magnesium salts of tall oil fatty acids synthesized at the stage of emulsion formation as a result of the interaction of the emulsifier-stabilizer with alkaline earth metal cations contained in the internal phase. The alkaline medium necessary for this reaction to occur is created both in the dispersion medium due to the presence of potassium salts of fatty acids in the specified emulsifier and in the dispersed phase due to partial hydrolysis in the aqueous medium of caustic magnesite (magnesium oxide). As a result of the formation of these soaps, a highly dispersed colloidal phase (micellar aggregates) appears in the system, which concentrates due to the diphilic properties of these compounds on the phase interface and creates a gel-like structure of increased viscosity and strength with stabilizing properties.

The secondary stabilizer, structure-forming agent and filtration reducing agent of this system is the complex “tall oil fatty acids - caustic magnesite”. It is known that the stability of emulsions can be significantly increased by stabilizing the phase boundary with solid active highly dispersed fillers. In invert emulsions - drilling fluids obtained by the proposed method, caustic magnesite (magnesium oxide) acts as such a filler, the surface modification of which occurs at the stage of emulsion formation due to chemisorption of high molecular weight fatty acids, as a result of which the MgO surface acquires oleophilic properties that contribute to the structure formation of interfacial protective shells on the surface of the globules of the dispersed phase. Thus, caustic magnesite, which is an integral ingredient of invert emulsion drilling fluids obtained by the proposed method, acts as a multifunctional reagent that enhances the interaction between the oleophilic base solution and the aqueous phase of the emulsion.

As a reagent that increases the rheological properties of the resulting drilling fluid at low shear rates, as well as the initial gel strength required for better cleaning of the bore of shallow and subhorizontal wells, a higher fatty unsaturated acid, for example, oleic acid, is additionally introduced acid. Due to the fact that in the proposed method for producing an invert emulsion drilling fluid, this acid is introduced at the end of the stage of formation and stabilization of the invert emulsion and does not participate in the reactions proceeding at the interface, it is evenly distributed in the oleophilic dispersion medium of the solution and, due to its tendency to polymerize, free -C = C-bonds forms in the oleophilic medium a network structure of long hydrocarbon chains interconnected by chemical and coordination bubbled bonds, providing a solution is even more elevated shear stress values at low shear rates.

In this application, the requirement of unity of invention is met, since the claimed emulsifier-stabilizer and the method of preparing an invert emulsion drilling fluid using this emulsifier constitute a single inventive concept and together solve the same problem - obtaining an invert emulsion drilling fluid for drilling mostly flat and horizontal wells, with the necessary rheological, thixotropic, pseudoplastic and filtration properties.

The proposed emulsifier-stabilizer and a method of preparing an invert emulsion drilling mud have been tested in laboratory conditions. In the tests, the following substances were used.

To prepare the emulsifier-stabilizer:

- products of tall oil processing based on higher fatty acids (their name and characteristics are given in table 1);

- potassium alkaline reagent;

- potassium hydroxide GOST 24363-80 or technical potassium carbonate (potash) GOST 10690-73;

- solvent - non-aromatic light mineral oil (their characteristics are given in table 2): industrial oil brand IP-12, IP-20, GOST 20799-88 or transformer oil, TU 38-401978-98 (unlike traditional oil products used in as solvents in known invert emulsion emulsifiers, these products are more environmentally friendly hydrophobic liquids that undergo biogenic degradation under aerobic and anaerobic conditions);

- technical or mineralized water with a density of 1000-1180 kg / m ³ .

To prepare an invert emulsion drilling fluid:

- calcium chloride GOST 450-77;

- caustic magnesia powder GOST 1216-75;

- oleic acid MRTU 6-09-3306-66;

- hydrocarbon reagent;

- mineral oils (industrial oil brand IP-12, IP-20, GOST 20799-88; transformer oil, TU 38-401978-98);

- lubricant and anti-seize additive ДСПБ-БС, ТУ 2452-002-52412574-00;

- esters of vegetable oils, GOST 1129-93.

The essence of the invention is illustrated by the following examples.

The inventive emulsifier-stabilizer is prepared as follows.

Example 1. 82.9 g of solvent — transformer oil of the VG brand — are placed in a beaker, 8.3 g of tall fatty acids, a product of tall oil processing, are poured into it with stirring, after 10 minutes of stirring, 8.7 g of 48% aqueous a solution of potassium hydroxide - potassium alkaline reagent, the mixture is stirred for 30 minutes, after which the composition is ready for use. The quantitative content of the obtained emulsifier is the following, wt.%: The product of tall oil processing based on higher fatty acids - 8.4; potassium hydroxide - 4.2; water - 4.5; solvent - non-aromatic light mineral oil - 82.9.

Example 2. 53.4 g of industrial oil of the IP-12 grade are placed in a beaker, 22 g of distilled tall oil are poured with stirring, after 10 minutes of stirring, 23.1 g of a 48% potassium hydroxide solution are added, stirred for 30 minutes and 1 5 g of caustic magnesite, the mixture is stirred for 30 minutes, after which the emulsifier is ready for use. The quantitative content of the resulting emulsifier is as follows, wt.%: Distilled tall oil - 22; potassium hydroxide - 11.1; water - 12; caustic magnesite - 1.5; solvent - industrial oil - 53.4.

Emulsifiers with a different ingredient content are prepared in a similar manner.

The obtained emulsifier-stabilizer for invert emulsions has the following physicochemical parameters: appearance - a viscous brown fluid with a density of 870-920 kg / m ³ , with a pour point of from -15 to -45 ° C.

The proposed emulsifier-stabilizer can be centrally prepared under production conditions and transported to the place of its use in the well, in addition, due to the simplicity of operations at the technical and economic feasibility, the preparation of the emulsifier from the above ingredients is possible in mixing devices (such as a clay mixer) directly in the well.

Then, an invert emulsion drilling fluid is prepared under laboratory conditions using a previously prepared stabilizer emulsifier. To do this, initially prepare a solution on an oleophilic (hydrocarbon) basis, for this take 500 g of a hydrocarbon reagent - esters of vegetable oils, 180 g of stabilizer emulsifier-stabilizer previously prepared according to Example 1 are introduced into it, while the mass ratio of hydrocarbon reagent and emulsifier is 2, 78: 1 respectively. A water-based solution is prepared separately, which is a mixture of an aqueous solution of calcium chloride with a concentration of 111 g / l and an aqueous solution of caustic magnesite with a concentration of 74 g / l, and these solutions are taken in a ratio of 2.13: 1. Then they are mixed together by introducing a water-based solution into an oleophilic (hydrocarbon) -based solution. In an advantageous embodiment, it is possible to divide the water-based solution into two portions in a volume ratio of 9: 1, which are then introduced sequentially into the oleophilic-based solution and the resulting mixture is mixed after each portion is added for at least 1 hour. In this case, an invert emulsion drilling mud of the following composition is obtained, wt.%: Emulsifier-stabilizer - 18; hydrocarbon reagent - 50; calcium chloride - 3; caustic magnesite - 3; fresh water - 26.

In order to increase rheological parameters at low shear rates, a higher fatty unsaturated acid, oleic or linoleic, in an amount of 0.5-2 wt.% Can be added to the obtained invert emulsion drilling fluid.

Invert emulsion drilling fluids obtained by the proposed method, with a different ratio of ingredients, are prepared in a similar way.

Table 3 shows data on the ingredient composition of the claimed and known prototype emulsifiers-stabilizers, as well as on invert emulsion drilling fluids obtained on their basis by the proposed method.

In laboratory conditions, the following properties of the indicated drilling fluids were investigated:

- filtration rate (Ф ₃₀ , cm ³ ), measured on a OFI dynamic filter press at ΔР = 0.7 MPa;

- rheological properties — plastic viscosity (η, MPa · s), dynamic shear stress (τ ₀ , dPa), gel strength (Gel, lb / 100 ft ² ), η, τ ₀ and Gel were measured on an OFITE viscometer; viscosity at low shear rate (VNSS, MPa · s) was measured on a Brookfield viscometer;

- the consistency index "K" was calculated according to well-known formulas [Macovei N. Hydraulics of drilling. - M .: Nedra, 1986];

- electrical stability was measured on an OFITE electrical stability meter.

Table 4 shows data on the properties of invert emulsion drilling fluids prepared using an emulsifier-stabilizer according to the known and claimed methods.

The data shown in tables 3-4 show that invert emulsion drilling fluids prepared by the proposed method and using the inventive emulsifier have low values of the filtration rate at ΔP = 0.7 MPa (Ф = 0-2.0 cm ³ / 30 min), technologically necessary rheological characteristics (η = 25-120 mPa · s, τ ₀ = 50-460, VNSS = 20000-40000 mPa · s) are characterized by the consistency indicator optimal for drilling shallow and horizontal wells (K = 0, 3-0.5), which corresponds to low hydraulic resistance; while emulsion drilling fluids obtained by a known method are characterized by high lubricating properties and high electrical stability (not less than 200 V).

Technical and economic advantages obtained by the proposed method invert emulsion drilling fluids in comparison with the prototype are as follows:

- the rate of filtration of the resulting solutions is less than the same indicator of the prototype, which provides less damage to the filtration-capacitive characteristics of the reservoir;

- the rheological properties of the resulting solutions, especially at low shear rates, have higher values than the prototype, and at the same time they meet the requirements for posting flat and subhorizontal sections of the wellbore.

Thus, as laboratory tests have shown, the method of preparing invert emulsion drilling fluids, as compared with the known technical solution, allows to obtain fluids with higher extension and retention properties while preserving the reservoir properties of the rocks of the opening section, which allows successful drilling of shallow and subhorizontal wells and qualitatively open productive layer.

In addition, invert emulsions (invert emulsion drilling fluids) obtained by the proposed method are characterized by almost unlimited salt resistance, high lubricating and inhibitory characteristics, good resistance to contaminants (clay, cement, formation water) entering the system and the possibility of reuse, which is especially important from a technical, economic and environmental point of view.

Table 1
Characterization of tall oil based tall oil processed products Indicator Higher Fatty Acid Tall Oil Processing Products Tal fatty acids Distilled tall oil Light tall oil Acid number, mg KOH / g 190-198 170-180 95-157 Saponification number, mg KOH / g 194-198 170-180 92-172 Resin acids, wt.% 1-3 12-45 1-5 Fatty acids, wt.% 93-97 64 49-74 Neutral substances, wt.% 2-5 3-5 22-48 Note: Tall fatty acids mainly comprise unsaturated fatty acids: oleic - 10.4-41.6%; linoleic - 26.1-54.7%; linolenic - 1.9-10.1%; isolinolenic - 3.1-5.6%; palmitoleic - 0.4-5.7%, etc., and saturated fatty acids: palmitic - 3.9-9.1%; stearic - 2.2-4.4%.

table 2
Characteristics of non-aromatic light mineral oils Indicators Industrial oils Transformer oil I-12A I-20A Vg T-1500U Kinematic viscosity at 40 ° С, mm ² / s 13-17 25-35 9 (50 ° C) eleven Pace. flashes in an open crucible. ° C, min 165 180 135 135 Pace. solidification, ° C, max -thirty -fifteen -45 -45 Acid number, mg KOH / 1 g of oil, max 0.02 0,03 0.01 - Ash content,%, max 0.005 0.005 - 0.3

Table 3
Data on the ingredient composition of the inventive emulsifier and prepared by the proposed method on its basis invert emulsion drilling mud №№ The ingredients of the emulsifier-stabilizer, wt.% The ingredients of the invert emulsion drilling fluid, wt.% Higher Fatty Acid Tall Oil Processing Products Solvent - Non-Aromatic Light Mineral Oils Potassium Hydroxide (Potassium Carbonate *) Caustic Magnesite Water Hydrocarbon reagent Emulsifier Water Calcium chloride Caustic Magnesite Oleic acid Distilled tall oil Tall Fatty Acids Transformer oil Industrial oil one 22.0 - - 53,4 11.1 1,5 12 20 ¹ 10.0 65.5 2 one 1,5 2 6.2 - - 53,4 11.1 - 29.3 40 ² 15.0 38 3 2 2 3 20,0 - 59.0 - 10.0 * - eleven 48 ² 5,0 42 2 2 one four - 8.4 82.8 - 4.2 - 4.6 50 ³ 18.0 26 2 3 one 5 - 22.0 54.0 - 11.0 1,0 12 60 ³ 10.0 25 2 2 one 6 - 10.3 79,4 - 4.8 - 5.5 46 ³ 14.5 36.5 2 one - Prototype 7 Acid esters Diesel - 51.5 - - tall oil and CaCl ₂ - 3.0 15,5 twenty four 76 - - - triethanolamine (Emultal) - 30.0 Note: 1. As a hydrocarbon reagent in experiment 1 used diesel fuel; in experiments 2 and 3 - transformer oil; in experiments 4-6 - esters of vegetable oils.

Table 4
Data on the properties of invert emulsion drilling fluids prepared using the proposed emulsifier-stabilizer according to the known and claimed methods No. of experience from table 3 Technological performance Plastic viscosity, MPa · s DNS, dPa Gel Strength lb / 100 ft ² Brookfield viscosity, mPa.s F ₃₀ cm ³ Electrical stability, V (0.1 MPa) (0.7 MPa) one 90 144 10/13 37500 0 0 265 2 79 120 7/9 35,400 0 0 275 3 81 134.4 6/7 25300 0 0 305 four 123 235.2 7/10 36000 0 2 355 5 134 182.4 6/9 27000 0 0.9 278 6 107 172.8 6/8 33600 0 1,5 283 7 21 42 - - 5 - 260

Claims (9)

1. Emulsifier-stabilizer of invert emulsions, including an oil-soluble surfactant surfactant, a mineral additive, water and a solvent, characterized in that as an oil-soluble surfactant it contains a tall oil fat processing product based on higher fatty acids, as a mineral additive - potassium alkaline reagent, and as a solvent - non-aromatic light mineral oil in the following ratio of ingredients, wt.%: Tall oil processing product based on higher fatty acids 6.2-22.0 Potassium alkaline reagent 4.2-13.5 Water 4,5-14,6 Solvent - Non-Aromatic Light Mineral Oil Rest 2. The emulsifier according to claim 1, characterized in that it further comprises caustic magnesite. 3. The emulsifier according to claim 1, characterized in that as the product of the tall oil processing based on higher fatty acids, it contains tall fatty acids, or distilled tall oil, or light tall oil. 4. The emulsifier according to claim 1, characterized in that as a non-aromatic light mineral oil it contains industrial or transformer oil. 5. The emulsifier according to claim 1, characterized in that as the potassium alkaline reagent it contains potassium hydroxide or potassium carbonate. 6. A method of preparing an invert emulsion drilling fluid, comprising preparing an oleophilic based solution by introducing an invert emulsion stabilizer emulsifier-stabilizer into a hydrocarbon reagent, preparing a water based solution, mixing them together by introducing a water based solution into an oleophilic based solution, characterized the fact that as a solution on an oleophilic basis, a mixture of a hydrocarbon reagent with an emulsifier according to claim 1 is prepared with their mass ratio (1.5-9): 1, respectively, as a solution On a water-based basis, a mixture of an aqueous solution of calcium chloride is prepared, providing a concentration of calcium ions in the aqueous phase of the resulting emulsion of at least 11.6 g / l and an aqueous solution of caustic magnesite with a concentration of 16-120 g / l, and the starting ingredients are taken in the following ratio, wt.%: Emulsifier according to claim 1 5-20 Hydrocarbon reagent 20-88 Calcium chloride 2-3 Caustic Magnesite 1-3 Fresh or mineralized water Rest 7. The method according to claim 6, characterized in that in the invert emulsion drilling fluid is additionally introduced higher fatty unsaturated acid - oleic, or linoleic, or α-linolenic acid in an amount of 0.5-2 wt.%. 8. The method according to claim 6, characterized in that mineral oil or lubricating additives for drilling fluids based on vegetable oils, or esters of vegetable oils, or synthetic fluids from the class of polyalphaoleins, polyalkylene glycols are used as the hydrocarbon reagent. 9. The method according to claim 6, characterized in that the water-based solution is divided into two portions in a volume ratio of 9: 1, which are sequentially introduced into the solution on an oleophilic basis and the resulting mixture is mixed after each portion is added for at least 1 hour.