SU1069630A3 - Drilling mud - Google Patents

Description

The invention relates to drilling fluids containing reversible emulsions. When searching for and developing such minerals as hydrocarbon containing ones, as well as in responsible drilling for geological and similar purposes, so-called drilling fluids are used for flushing boreholes. Previously, so-called water drilling muds were used for this purpose. Oily, ie using oil as a carrier, drilling muds have been used with great success only over the last 20 years and especially for deep drilling 1 (deeper than 3000 m), as well as for special tasks, for example, when crossing wells (through holes) in layers of swelling (swelling) clay or cracking shale and with through holes in the layers supplying hydrocarbon substances. Extremely high (hard) requirements are imposed on these solutions: at high pressures and temperatures, they must retain their good rheological properties, their stability, ability to retain water and oil (in them), and ability to hydrate (restore moisture content). The main type of oil-based drilling fluids are the so-called Nftiie black slimes containing high-boiling fractions of mineral oils, asphalt, asphalt resins and iron tl3. Black sludge has the disadvantage that due to the coloration it can only be difficult to distinguish when the well has reached the oil-bearing layers. In addition, asphalt and even more asphalt resins are clogged with oil pores containing layers having a porous structure. In terms of drilling technology, the so-called white sludges exhibit the best properties. White muds are drilling muds, which consist of high-boiling oil fractions (gas oil, petroleum, etc.), clay minerals with a modified surface (bentonite, t at t-pulgite), humic acids with a modified surface or lignin. further from two or three different surfactants. Also known drilling mud so-called emulsion or reversible emulsion drilling sludge. They are different from sludges created only on an oil base, primarily because the basic medium for them is an emulsion of water (oil) type: 21. However, these solutions are not suitable for deep drilling, as they do not contain the required amount of iron. and as a result, they do not have sufficient specific weight. Also known is drilling mud (white drill cuttings), created on the basis of an invert emulsion, containing an oil fraction free from tar and asphaltenes, water, an emulsifier and oleophilized barite, treated with a surfactant selected from the group of compounds of the general formula RM CCH- iljN j ltx.- or R UjlIX, where R is alkyl or alkenyl, X is an acid residue, and for treatments take 3-6 wt.h. surfactant 1000 wt.h. barite. The known drilling fluid may contain up to 70% by weight of the gel (barite) and maintain stability and good rheological properties of C 3. The disadvantage of the known solution is the insufficiently high thermal stability, as a result of which this solution is unstable: under conditions of ultra-deep drilling. The aim of the invention is to increase the stability of the solution under super-deep drilling conditions. This goal is achieved by offering a drilling fluid containing the following ingredients, in% by weight: Oil per fraction, free from asphalt-resinous substances 30-67 Organophilic clay minerals and / or organophilic humic acids 0.3-4 Fatty acid calcium salt 0 , 9-2 Water9-14 Oleophilizing barite, treated with sodium salts of fatty acids (3-6 parts by weight of acids per 1000 parts by weight of barite) 13-62 Thus, for very deep drilling, sludge is necessary, the specific weight of which can vary widely (1.0-2.5 r / ci) without significant o change in rheological slurry sludge. If, for example, the yield strength is the resistance to movement (according to Bungham) of the sludge after 10 s and after 10 min to investigate after

slice (separation), then both values should be close to each other and lie in the range of 25-250 dyn / cm. In addition, sludge at high pressures and temperatures should remain stable and only give out liquid in small quantities (100 ml of sludge at 7 atm for 30 minutes can lose a maximum of 7 ml of liquid), and the sludge should not precipitate from the sludge ( maximum permissible sediment thickness of sludge 2, 5 mm). In addition, the rheological properties (flow properties) should not deteriorate also under prolonged exposure to high temperature (220 ° C for 6 hours) and neither apparent nor differential viscosity should decrease.

The provision of the Leophilicity of ut utela can be performed in various ways. It is advisable to prepare an aqueous suspension from solid solids and add the required amount of tensides with active stirring. Then oleophilic precipitates are precipitated, filtered, washed, dried and disintegrated (crushed).

The degree of oleophilicity to which the desires should be adjusted is determined both by adsorption, sedimentation volume, sedimentation rate, and rheological properties. Because of this set of factors, numerous experiments were carried out in gas oil with suspensions made of surface leophilic barium sulfate, calcium carbonate, quartz, and other stimulants. Were investigated: nn also suspensions made and mixtures of the presented materials together with organophilic clay minerals and organophilic humic acids.

f.

Experiments have shown that when using those desires, the surface properties of which were modified to create oleophilicity, the suspensions give significantly different properties, namely, friend stability, oil retention, other rheological properties (yield strength, viscosity, thixotropy, etc. .). These properties are extremely important for drilling technology; by selecting the level of oleophilicity, these properties can be adjusted depending on the need over a wide range.

Oleophilized samples are well combined in drill cuttings with organophilic clay and organophilic humic acids. The latter is extremely important when forming the structure of the suspension.

If only a portion of the outer surface of the webs is coated with an oleophilizing surfactant (0.2–0.3 g of surfactant per 100 g of the ut g), then the surface has an oleophilic-oleophobic micro-mosaic structure. In this case, a relatively strong adhesion force arises between the UHG particles and the gas oil, with the help of which the need is maintained in the sludge

0 structure stability and stability. This is necessary for oily sludges made with a relatively small specific gravity (1.001, 70 g / cm). For these sludges, such

5, is used for oleophilization of the gel of the gel 0.2-0.3 wt.% Surfactant. The Bbttjie specific gravity of the drill cuttings, the more it must contain ut zheltel. This can be achieved at a higher level of oleophilicity of the body weights (0.4–0.6 wt.% Surfactant), since in such cases it is advantageous if the entire surface of the utter gland is covered with surfactant molecules. The required stability of the suspension can be guaranteed only by a system that is well-moistened with oil, with a high degree of filling volume.

It was further found that, with surface-oleophilic attenuators, not only oil drilling sludges, but also drilling sludges based on so-called reversible emulsions can be obtained. These drill cuttings

5 which are reversible water-oil on the emulsion, are important because their rheological properties change by a smaller amount with increasing temperature than in the case of sludges with the medium in the form of pure oil.

In making the proposed drilling sludge composition, it was found that the oleophilic clays used as the medium for the first mixing were first soaked and then peptized, while at that time the oels having oleophilic surfaces were disaggregated. In this way, a system with a completely homogeneous distribution is created. Pepticuli of organophilic clay and disaggregation of oleophilic destabilizers may be desirable with appropriately selected additives, for example, hydroxide sulfide, alkali, adduct of ethylene oxide and oleic acid, and others.

In the manufacture of sludges based on reversible emulsions, it was found that it becomes particularly stable with water-oil on the emulsion when an emulsifying agent is formed during the emulsification process on the boundary surface of the water and oil (before

5 da or oil) from anhydrous or non-oily components. The proposed composition of white drill cuttings containing oil or reversible emulsions possesses in excess all the properties required in accordance with the drilling technique. The proportion of these sludges can be adjusted over a wide range (1.00-2.50 g / cm). Both their apparent viscosity and differential viscosity do not decrease, the yield strengths measured directly after the cut (separation of part of the sludge) or 10 minutes later lie very close to each other and slightly change at high temperatures (and higher). high temperature, the property of oil retaining water and water is well preserved, and sediment is almost not accumulated from drill cuttings. A particular advantage of the proposed drill cuttings based on reversible emulsions is that it absorbs water in the event of a water breakthrough into a well, and does not significantly change its properties. In the manufacture of oily brown sludge, they are moistened to promote swelling and peptization of surfactants at .0-50 ° C and high-boiling (over 200 ° C oil refluxes, for example, in gas oil, then with intensive mixing, organophilic clays and humic acids and, in finally, homogenization of the emulators is done, which are then made oleophilic. In making the proposed boom sludge on the basis of reversible multies, first weights.% of fatty acids from 6 to 30 carbon atoms in high boiling fractions of oil are first dissolved, then under intensive grinding to 10–40 wt.% of water containing 1–10 wt.% based on the weight of water of hydrated lime is added to the reversible emulsion prepared in this way, first with a surfactant that promotes swelling and peptization, and then with vigorous stirring in portions of organophilic clay and / or humic acids, and at the end of the process the solution is mixed and homogenized -EU with emulsifiers having olzophilic surfaces. Example 1. In 100 g gas oil at 20-40 ° C dissolve 1 g of normal ocetyl squeehydrophosphate and in the solution with vigorous stirring 4 , 4 g IVEGEL (org nofilny bentonite: manufactured Eszakmargyarorsz9 .gij (Hungary), then for 10 min was stirred. Then the suspension is left overnight. On another day, the solution is re-homogenized by stirring for 10 minutes, then 106 g of precipitated brite (barium sulfite) are added in portions. Example 2. Similar to Example 1, but characterized in that, instead of pure barium sulphate, 106 g of barium sulphate is added to which oleophilicity is imparted by adding 0% by weight of sodium salt of fatty acids (sodium oleate). Example 3. Analogous to example 1, but instead of 106 g of precipitated barium sulfate, 106 g of precipitated barium sulfate was applied, which was oleophilized by the addition of 0.3 wt.% Sodium salt of fatty acids (sodium oleate). Example 4. The suspension is prepared as described in Example 1, but instead of 10.6 g of precipitated barium sulfate, contains 106 g of precipitated barium sulfate, which is oleophilic by the addition of 0.4 wt.% Sodium oleate. The most important rheological properties of drill cuttings manufactured in accordance with examples 1-4 are shown in table 1. It can be seen from Table 1 that by adding barium sulphate with different degrees of oleophilicity in the initial identical compositions with the same specific weight, the yield strength by Binpham plastic viscosity || rv of drill cuttings is significantly reduced. Example 5. With 100 g of gas oil at 20-40 ° C, 3.0 g of emulsifying agent is mixed, for example, Ethonsen S-12 (calcium fatty acid soap) and 20 g of water. Then, 6.0 g of IVEGEL (organophilic bentonite) are added in small portions with vigorous stirring. After the addition is complete, the solution is stirred / left to stand overnight for another 10 minutes, mixed again for another 10 minutes and then first 1 g of n-octyl-sesqui hydrogen phosphate is added, and then 20 g of ground barite with vigorous stirring which is given oleophilic acid with 0.2 wt.% sodium salts of fatty ACIDS; Example 6. Analogous to example 5 with the difference that 5 g of IVEGEb and 106 g of ground barite are applied, which is given oleophilicity by adding 0.3 wt.% Sodium salts of fatty acids. Example 7. Similar to example 5, but instead of the amount given there, 1.8 g of IVEGEL and 178 g of ground barite are applied, which is given oleophilicity by adding 0.4% by weight of sodium salts of fatty acids. Example 8. Similar to Example 5, but using 1.5 g of IVEGEL 196 g of ground barite, which is added oleophilicity with the addition of 0.6 wt.% Sodium salts of fatty acids. Example 9. Similar to example 7, however, before adding a mixture containing 1.5 g of IVEGEL and 178 g of crushed barite, to which oleophilicity is imparted by adding 0.4% by weight of sodium salt of fatty acids, 1.5 g of organophilic humic acids are added. The rheological parameters and stability of the properties of emulsion drilling ishams prepared according to examples 5-9 are given in table 2. Apparent and differential viscosity was measured with a Papp / y rotary viscometer at 600 rpm. The yield strength after 10 s and 10 min after the cut was measured with an autometer for the same type. The liquid discharge, as well as the amount of sediment (thickness of sediment from sludge), was determined after 30 minutes at 7 atm. Once measurements were taken at room temperature, the other - after a 16-hour exposure to 220 ° C. In the latter case, the temperature of the drill cuttings was still measured at 220 ° C. From the data of Table 2 it is clearly seen that the proposed drill cuttings, which have very different specific gravities (1.10-2.20 g / cm), show approximately identical rheological properties and are very stable, almost temperature independent, systems . In Table 2, the parameter of the solutions is indicated as follows: 1.- Specific gravity, g / cm, 2.- Apparent with viscosity. cP (measured by a Papp / u rotational viscometer at 600 rpm). 3.- Differential viscosity, cP (measured in the same way). 4.- Resistance of movement after 10 s, dyne / cm (measured by a Papp / y rotational viscometer). 5.- Resistance to movement after 10 min, dyne / cm - (measured by rotational viscometer. By Papp / y). 6.- Liquid loss, ml (from 100 ml at 7 atm for 30 min). 7.- Water thickness in lost liquid, ml. 8.- Sludge sediment thickness, ml. In addition, two measurements were made in each example: measurement corresponds to room temperature, measurement 4 is the result of measurement after 16 hours of exposure to temperature. Table 1

ABOUT

0.2

0.3

about 0.4

- Bingham t 1U yield strength - plastic viscosity 1,101,101,501,502,002.00 3748 67867498 2737 51695776 2224 58576363

580

80

180

21

74

13

45

6

Table 2 2,242,242,002,00 87,510287102 69 846786 80,562,57743 48 49 72 77 86 96 3/0 .0.2 3.6 0.2 4.0 05 1.5 0.5 2.0 2.0 0.5 2, 0

Continued table. 2 8877, 5 8681 4.04.8 -5.8 - -2.0 1.02.5 0.52.0

Claims (1)

A DRILLING MIXTURE containing an oil fraction free of * asphalt-resinous substances, emulsifier, water, oleophilized barite treated with surfactants in an amount of 3-6 parts by weight surfactant per 1000 parts by weight of barite, characterized in that, in order to increase the stability of the solution under ultra-deep drilling conditions, it additionally contains organophilic clay minerals and / or organophilic humic acids, calcium fatty acid as an emulsifier, and sodium barite treated as oleophilized barite fatty acid in the following ingredients, May.%: Oil fraction Organophilic clay minerals and / or organophilic humic acids Fatty Acid Calcium Salt Water Oleophilized Barite Ratio 13-62