RU2242491C2 - Multifunctional reagent for treating drilling fluids "kemfor-msmg" and a drilling fluid treatment method - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: multifunctional reagent containing sulfate soap (67.5-87.75%) and cellulose or starch ethers (1.55-9.0%) additionally contains mineral oil with cinematic viscosity up to 49 mm²/c (cSt) at 20^оС or vegetable oil with cinematic viscosity up to 6.7 mm²/c (cSt) at 30^оС, 3.34-16.7%, and graphite, 1.66-12.5%. Reagent is added to drilling fluid in amount 0.2 to 25% on the weight of frilling fluid. Utilization of such reagent results in suppressed boring-caused aeration of drilling fluid, acquired by them combined lubricating and antiwear properties at various types of friction, multifold reduced sticking properties of drilling fluids due to decreased shear tension and friction factor throughout filtration crust, slowed wear of drilling tool due to strengthened lubricating properties of clayey drilling fluids, and increased heat resistance for drilling fluids.

EFFECT: improved performance characteristics of drilling fluids.

2 cl, 9 tbl, 2 ex

Description

The present invention relates to the drilling of oil and gas wells, can be used in the preparation of a reagent for drilling fluids and is intended to implement the technology of chemical treatment of drilling fluids.

It is known to use sulfate soap for processing drilling fluids [1, 2, 3]. But in the initial (raw) form, the use of this substance is extremely complicated by freezing and the inability to dispense at low temperatures, intensive foaming of drilling fluids, and high costs.

It is widely described the use of sulfate soap derivatives as additives for drilling fluids: crude tall oils [4, 5, 6]; light tall oil [7, 8, 9, 10, 11]; tall oil distillate acids [12, 13]; their amides [14]. The above compositions have only specific uses as lubricant additives. However, having good lubricating properties, even at high costs for processing drilling fluids, these substances slightly reduce filtration.

The use of vegetable oils in drilling fluids is described [15]; products of their processing [16, 17]; soap stocks [18, 19]. It is known that mineral oils [20] and their compositions with fatty acids [21, 22] and others are used in practice. The mentioned analogues have their own specifics and limitations: they do not independently create and do not support thixotropic systems, and do not have antifiltration properties.

Known reagent for processing clay solutions "Kemfor-MSM" [23], containing cellulose or starch esters and sulfate soap, while it contains ingredients in the following ratio, wt.%:

cellulose or starch esters 2.5-10

sulfate soap

(per dry residue) 90-97.5

The multifunctional reagent “Kemfor-MSM”, taken by us as a prototype, is also highly effective compared to the known ones. But this reagent is characterized by the negative ability of technogenic aeration, which manifests itself in foaming of the drilling fluid during its mixing, movement and exposure to units of the drilling rig treatment system. By their chemical nature, the reagent does not sufficiently realize the possibilities of preventing or weakening complex (combined) types of friction [23].

The technical task of the proposed solution is to eliminate man-made aeration of drilling fluids, giving them universal lubricating and anti-wear properties in combined types of friction, a multiple reduction in the sticking properties of clay drilling fluids by reducing shear stress and friction coefficient along the filter cake, reducing the wear rate of the drilling tool due to intensification lubricating properties of clay drilling fluids, increasing the heat resistance of drilling fluids.

The problem in the multifunctional reagent for processing drilling fluids containing sulfate soap, cellulose or starch esters, mineral or vegetable oil and graphite, is solved by the fact that it contains these ingredients in the following ratio, wt.%:

sulfate soap (on the dry residue) 67.5-87.75

cellulose or starch esters 1.55-9.0

graphite 1.66-12.5

mineral oil with kinematic

viscosity at 20 ° С no more

49 mm ² / s (cSt) or vegetable oil

with kinematic viscosity at

20 ° С no more than 6.7 mm ² / s (cSt) 3.34-16.7

Salient features in the claimed invention are:

- multifunctional reagent for processing clay drilling fluids additionally contains mineral or vegetable oil and graphite in the following ratio of components, wt.%:

- mineral oil with kinematic viscosity at 20 ° C not more than 49 mm ² / C (cSt) 3.34-16.7;

- or vegetable oil with kinematic viscosity at 20 ° C not more than 6.7 mm ² / s (cCT) 3.34-16.7;

- graphite 1.66-12.5.

A known method of processing drilling fluids, including introducing into drilling fluids a reagent consisting of cellulose or starch ethers and sulfate soap, wherein said reagent is obtained from wt.%: Cellulose or starch ethers 2.5-10 and crude sulfate soap (dry residue) 90-97.5, injected into the drilling fluid in an amount of 0.25-1.0 wt.% of the volume of the drilling fluid [23].

The disadvantage of this method of processing drilling fluids, taken by us as a prototype, is the negative ability of technogenic aeration, which manifests itself in foaming of the drilling fluid when it is mixed, moving and exposed to the aggregates of treatment systems of drilling rigs.

The technical task of the claimed method of processing drilling fluids is to eliminate technogenic aeration of drilling fluids, giving them universal lubricating and anti-wear properties in combined types of friction, a multiple reduction in the sticking properties of clay drilling fluids by reducing shear stress and friction coefficient along the filter cake, reducing the wear rate of the drilling tool due to the intensification of the lubricating properties of clay drilling fluids, increasing the heat resistance of drilling astvorov.

To implement the technical solution, raw sulfate soap was used, which is a greasy substance from dark yellow to dark brown. Sulphate soap consists of approximately equal amounts of sodium salts of tar and fatty acids and a relatively smaller amount of oxidized and unsaponifiable substances. Contamination contains a significant amount of lignin, minerals and other substances contained in black liquor and recovered by sedimentation with sulfate soap. Quantitative characteristics of sulfate soap are presented in table. 1.

The technical solution used mineral oils - liquid mixtures of hydrocarbons: a) distillate - obtained by distillation of oil; b) residual - obtained by removing components from the tar; c) compounded - obtained by mixing distillate and residual mineral oils. In particular, industrial oils are distillate petroleum oils of low and medium viscosity (5-50 mm ² / s at 50 ° C). Compressor oils with a viscosity of 7-30 mm ² / s at 100 ° C are obtained by deep refining of petroleum oils.

Common, relatively low-cost liquid vegetable oils are used. Qualitative characteristics of mineral and vegetable oils are presented in table. 2.

Graphite is a carbon modification that crystallizes in a hexagonal layered structure. Lubricating graphite grade P was used in accordance with GOST 8295-73, which is characterized by a mass fraction of carbon of at least 91%, an ash content of not more than 7%, and a pH of an aqueous extract of 6.0-8.2.

Cellulose and starch esters produced by Poly-Cell CJSC (Vladimir) were used. Their characteristics are presented in table. 3.

In the known method of processing drilling fluids, the problem is solved by introducing into the drilling fluids a reagent obtained with the following composition and ratio of components, wt.%: Cellulose or starch esters 2.5-10 and crude sulfate soap (on dry residue) 90.0-97 , 5, and the reagent is introduced in an amount of 0.25-1.00% by weight of the drilling fluid.

Salient features of the claimed method of applying the reagent for drilling fluids are:

- the reagent additionally contains mineral or vegetable oil and graphite obtained from wt.%: cellulose ethers or starch 1.55-9.0, crude sulfate soap (on dry residue) 67.5-87.5; graphite 1.66-12.5; mineral oil with kinetic viscosity at 20 ° C not more than 6.7 mm ² / s (cSt) 3.34-16.7;

- the reagent is introduced in an amount of 0.2-2.5% by weight of the drilling fluid.

The above salient features of the multifunctional drilling fluid processing reagent and the drilling fluid processing method were unknown to us from patent and scientific and technical information, and in this regard, we believe that they are new, i.e. have novelty.

The efficiency of preventing technogenic aeration achieved by the proposed multifunctional reagent is associated with the synergistic mechanisms of self-destruction of foam films containing graphite microparticles and low-strength films, including emulsified submicrodrops of mineral or vegetable oils. The noted feature of the anti-foaming mechanism is not obvious, is not described in scientific and technical publications and is an aspect of the compliance of the proposed solution with the criterion of “inventive step”.

The claimed invention has successfully passed laboratory tests and approbation during well drilling, which allows us to claim that it meets the criterion of “industrial applicability”.

To clarify the conformity of the proposed solution to the criterion of “industrial applicability” we give examples of the preparation of a reagent:

Example 1 (prototype)

1.8-2.0 g of grade 7C carboxymethyl cellulose is added to 100 g of crude sulfate soap with a residual moisture content of up to 30%. After removal of about 30 wt.% Water, a reagent of composition 1 is obtained (according to Table 4), containing 97.5 wt.% Of the dry residue of sulfate soap, 2.5 wt.% Of carboxymethyl cellulose (CMC) with a moisture content of about 2 wt.%.

Example 2

1.8-2.0 g of grade 7C Na-carboxymethyl cellulose is added to 100 g of crude sulfate soap, and then treated with a mixture of transformer oil of grade ТСп and graphite at a ratio of 2: 1 in an amount of 20% by weight of the dry intermediate. The result is a reagent of composition No. 15 (according to Table 4), containing 78% of the dry residue of sulfate soap, 2.0% Na-CMC (grade 7C), 6.64% graphite and 13.36% transformer oil (grade ТСп).

In accordance with this example, various reagent formulations were prepared, differing in the quantitative ratio of ingredients (Table 4), the qualitative composition of the oils used (Table 5), and the qualitative composition of cellulose or starch esters (Table 6).

For experimental verification of the proposed method for processing drilling fluids was prepared 101 composition of the reagent (table 4-6). The processing technology consisted of introducing a reagent with the claimed ratio of components into a previously prepared model drilling fluid and mixing for 0.5-1 hours on a paddle mechanical mixer at a speed of 500 rpm.

The resulting reagent is a granular substance with a fraction size of mainly 5-15 mm (up to 75%). Externally, the reagent is a porous oily granules of black or silver-black; easily dosed, not frozen. Humidity not more than 5-7%. The solubility of the reagent (in addition to the graphite component) is 99-100%. The concentration of hydrogen ions for a 1% solution of 9.5-10.5. If it is necessary to enhance certain properties of the drilling fluid, the ratio of components in the reagent can be changed. The resulting reagent does not apply to corrosive, radiation, explosives and does not have spontaneous combustion properties.

The reagent was tested in accordance with RD 39-22-645-81 “Method for monitoring the parameters of drilling fluids” on model drilling fluids prepared on industrial clay powders. The anti-wear characteristics of drilling fluids were determined on an MT-2 friction machine, the coefficient of friction of the clay cake on the FSK-2 device, the stickiness coefficient of the clay cake on the advanced VSN-2 device.

Model drilling fluids treated with a reagent with component concentrations lower and higher than the declared values do not solve the problem posed by the invention in the field of eliminating technogenic foaming and effectively reducing tribological parameters (anti-wear and combined friction processes).

According to the table 7 in examples No. 5, 6, 29, 30, 53, 54, the qualitative composition of the reagent is beyond the scope of the formula. In the examples No. 2, 3, 10-12, 17-19, 23, 24, 26, 27, 34-36, 41-43, 47, 48, 50, 51, 58-60, 65-67, 71, 72 quantitative ratios between the components of the reagent are beyond the scope stated in the claims. And, as a result, the technical solution is not achieved or is not effective.

The above reagents, in which the indicated ratios are not observed, give the model solutions significant foaming, reduced heat resistance, high values of the friction and stickiness coefficients, and multiply large tribotechnical characteristics.

The introduction of an oil-graphite mixture of less than 10% does not eliminate technogenic aeration and a sufficient improvement of tribological properties, and an increase in the content of the impregnating composition of more than 25% is not economically feasible, because however, there is no increase in useful properties, but the filtration of the liquid phase of the drilling fluid increases.

From the tables of the compositions of the reagent 4-6 and test tables 7-9 it is seen that the area of the optimal content of the components can be considered, wt.%:

sulfate soap (on the dry residue) 67.5-87.75

cellulose or starch esters 1.55-9.0

graphite 1.66-12.5

mineral or vegetable oil 3.34-16.7

The inventive multifunctional reagent for processing drilling fluids by chemical nature is a balanced concentrate of anionic surfactant-sodium salts and free fatty acids of sulfate soap, triglycerides and hydrocarbons. Therefore, the reagent is especially effective as an antiwear additive at high contact pressing loads (18-22 MPa).

As a result of the use of a multifunctional reagent with the proposed composition in the medium of drilling fluids, chemical modification of the friction surfaces occurs, and a three-dimensional combined lubricating layer is formed. On a graphite film of high hardness, the strength and elastic modulus of which increases with increasing temperature, the molecules of fatty (carboxylic) acids and salts of sulfate soap are adsorbed flatly, and the molecules of mineral or vegetable oils are complementary distributed, forming polymolecular layers. Their formation provides increased resistance of bit steel to fatigue wear.

A significant advantage of the claimed multifunctional reagent is a controlled decrease in the surface tension coefficient of the filtrate of drilling fluids (table. 9), which favorably affects the processes of opening productive intervals and significantly reduces the energy consumption of the rock destruction process by reducing their hardness.

Analysis of known technical solutions showed that in science and technology there is no object similar in terms of the claimed combination of features and advantages, which allows us to conclude that the proposed solutions meet the criteria of “novelty” and “inventive step”.

The analysis of the experimental results (table 7-9) shows that the individual, disparate components of the reagent composition and their individual combinations cannot provide such technological properties of the drilling fluid that the claimed multifunctional reagent gives it.

The above technical results are ensured by the joint use for the first time as a reagent that prevents technogenic aeration and synergistically intensifies antiwear, lubricating and anti-seizing activity of oil-graphite mixtures in combination with sulfate soap and cellulose ethers and starch.

The invention has an inventive step, since the possibility of reducing technogenic aeration of drilling fluids by using oil-graphite mixtures and imparting a new set of technological properties to the claimed new qualitative and quantitative compositions of a multifunctional reagent for a specialist does not explicitly follow from the prior art.

The characteristic properties of this multifunctional reagent for processing drilling fluids do not follow from the properties of the components, but appear only in their totality in the indicated ratios. This also indicates that the proposed solutions meet the criteria of “novelty” and “inventive step”.

Comparative analysis allows us to conclude that the inventive multifunctional reagent for processing drilling fluids differs from the known prototype by the introduction of new components, namely mineral or vegetable oils and graphite.

The practical applicability of the new method of processing drilling fluid is confirmed by the industrial application of the inventive reagent in drilling wells.

The primary treatment of the drilling fluid (to improve the lubricating properties and the quality of the clay crust) is carried out by adding a reagent in the amount of 5-10 kg per 1 m ^{3 of the} solution located in the circulation system and the well, in the form of a mixture with clay powder, for which:

- in a clay mixer, 2/3 filled with water, 250-500 kg of the inventive reagent is loaded and mixed until dissolved (heating water to 20-30 ° C speeds up dissolution);

- clay powder is added in an amount of 150-200 kg, and the mixture is again mixed for 0.5 hours

A clay slurry with a reagent is introduced into the drilling fluid during the cycle.

The frequency of administration and the concentration of the multifunctional reagent, if necessary, repeated treatments is determined during drilling. Maintaining the concentration of the inventive reagent is carried out by adding it in an amount of 50-80 kg per 4 m ^{3 of} drilling mud based on bentonite clays, prepared to replenish the circulating volume.

To increase the stability of the walls of the wells, enhance anti-filtration and lubricating properties, the content of the claimed multifunctional reagent for processing drilling fluids is increased to 1.5-2.5% by weight of the solution. Depending on the composition of real drilling fluids, the introduction of the claimed reagent can reduce the viscosity and SNA (in medium and high density solutions) or increase these parameters. Before working in wells, it is necessary to check the technological impact of introducing a reagent into samples of real drilling fluids in laboratory conditions. If it is necessary to dilute the solution, it is advisable to use GKZh-10 reagent (11). The inventive multifunctional drilling fluid processing reagent is compatible with all components of water-based drilling fluids.

The effectiveness of the method of processing drilling fluids is determined by the synergistic interaction of the components of the reagent (group of examples No. 4, 5, 6; 28, 29, 30; 52, 53, 54 according to table 7).

The inventive multifunctional reagent for processing drilling fluids is intended to solve the following problems:

reducing the thickness and increasing the density of the clay crust, significantly reducing the filtration of the drilling fluid into the near-wellbore formation and inhibiting the softening of the rock;

- slowing down the dispersion of rocks in the well;

- a significant reduction in the adhesive properties of the filter cake and the friction coefficient on the surface of the cake, rock, and the inner surface of the casing;

- optimizing the rheological characteristics of the drilling fluid and improving the conditions for the removal of sludge;

- improving the quality of opening of reservoir rocks, including facilitating the restoration of their permeability after drilling.

The reagent retains its properties at a temperature in the well up to 150-180 ° C.

Due to the versatility of the proposed reagent, it is realistic to provide it with a set of improving characteristics of the drilling fluid during chemical treatment and reduce its cost.

We are applying for the assignment of the name “Kemfor-MSMG” to the claimed multifunctional reagent for processing clay drilling fluids.

Sources of information

1. Epstein E.F., Titarenko N.K., Davidenkov A.N. et al. “Sulphate soap as a lubricant for drilling fluids”. In the book. “Issues of deep drilling for oil and gas.” Lviv: UkrNIGRI, issue. 4, 1974, p. 74-76 (analog).

2. The study of the influence of chemical reagents on the lubricating properties of drilling fluids / V.D. Tur, L. M. Sofrygina, N. B. Ponomareva, N. A. Shavrina. On Sat Proceedings of VNIIGNI “Technology for Drilling and Testing of Exploratory and Exploratory Wells”, vol. 247, M., 1983, p. 122-131 (analogue).

3. The use of waste pulp and paper industry for drilling in the Far North / T.A. Motyleva, N.G. Kashkarov, Yu.T. Ivchenko, M.M.Shalyapin, N.N. Verkhovskaya M .: VNIIEgazprom, 1989 , 26 s (review inform. Ser. Drilling of gas and gas condensate wells, issue 5) (analog).

4. Copyright certificate of the USSR No. 1775455, IPC S 09 K 7/02, publ. 11/15/92 (analog).

5. USSR author's certificate No. 1792959, IPC S 09 K 7/02, publ. 02/07/93 (analog).

6. USSR author's certificate No. 1693018, IPC S 09 K 7/06, publ. 11.23.91 (analogue).

7. Copyright certificate of the USSR No. 1542950, IPC S 09 K 7/02, publ. 02.15.90 (analog).

8. RF patent №2123023, IPC S 09 K 7/02 (IPC S 09 K 7/02), publ. 12/10/98 (analogue).

9. RF patent No. 2142978, IPC S 09 K 7/02, publ. 12/20/99 (analog).

10. RF patent No. 20133434, IPC S 09 K 7/02, publ. 05/30/94 (analog).

11. RF patent No. 2118648, IPC S 09 K 7/02, publ. 09/10/98 (analogue).

12. USSR author's certificate No. 883138, IPC S 09 K 7/02, publ. 11.23.81 (analogue).

13. USSR author's certificate No. 1669966, IPC S 09 K 7/02, publ. 08/15/91 (analog).

14. Copyright certificate of the USSR No. 870427, IPC S 09 K 7/02, publ. 10/07/81 (analog).

15. RF patent No. 2130475, IPC S 09 K 7/02, publ. 05/20/99 (analog).

16. RF patent No. 2076132, IPC S 09 K 7/06, publ. 03/27/97 (analog).

17. USSR author's certificate No. 1808862, IPC S 09 K 7/06, publ. 04/15/93 (analog).

18. USSR copyright certificate No. 715616, IPC C 10 M 1/06, publ. 04/03/78 (analog).

19. Copyright certificate of the USSR No. 1196369, IPC S 09 K 7/02, publ. 12/07/85 (analog).

20. Copyright certificate of the USSR No. 1002344, IPC S 09 K 7/02, publ. 03/07/83 (analog).

21. Copyright certificate of the USSR No. 1004440, IPC S 09 K 7/02, publ. 12/19.80 (analog).

22. Copyright certificate of the USSR No. 1208062, IPC S 09 K 7/02, publ. 01/30/86 (analog).

23. RF patent No. 2187530, IPC S 09 K 7/02, publ. 08/20/2002, bull. No. 23 (prototype).

Claims (2)

1. A multifunctional reagent for processing drilling fluids containing sulfate soap and cellulose or starch ethers, characterized in that it additionally contains mineral or vegetable oil and graphite in the following ratio, wt.%: Sulphate soap (on the dry residue) 67.5-87.75 Cellulose or starch esters 1.55-9.0 Graphite 1.66-12.5 Kinematic Mineral Oil viscosity at 20 ° С no more 49 mm ² / s (cSt) or vegetable oil with kinematic viscosity at 20 ° С no more than 6.7 mm ² / s (cSt) 3.34-16.7 2. A method of processing drilling fluids, comprising introducing into the drilling fluids a multifunctional reagent consisting of cellulose ethers or starch and sulfate soap, characterized in that the reagent further comprises mineral or vegetable oil and graphite in the following ratio, wt.%: Cellulose ethers or starch 1.55-9.0, crude sulfate soap (on a dry residue) 67.5-87.75, graphite 1.66-12.5, mineral oil with kinematic viscosity at 20 ° C not more than 49 mm ² / c (cSt) or vegetable oil with kinematic viscosity at 20 ° C not more than 6.7 mm ² / s (cSt) 3.34-16.7, and the reagent is introduced in an amount of 0.2-2.5% by weight of the drilling fluid.