MX2013008321A - Non-ionic hydroxyethyl cellulose and use thereof as a suspension for drilling, finishing and repairing oil and gas wells. - Google Patents

Abstract

Non-ionic hydroxyethyl cellulose, which is a product for facilitating the induction thereof in oil wells, this being a viscosity agent faster than conventional agents, the management thereof being more efficient, removing the product loses instead of using the powder version. The invention has a higher dispersion, in the different types of slurries used for the drilling, repair and finish of oil and gas wells. In addition, this product is environmentally friendly.

Description

HYDROXYETHYL NON-IONIC CELLULOSE AND ITS USE AS A SUSPENSION FOR THE DRILLING, TERMINATION AND REPAIR OF WELLS PETROLEUM AND GAS DESCRIPTION OBJECT OF THE INVENTION The present invention relates to the composition, method of preparation and application of a fluid product, formulated with a mixture of Hydroxyethyl Cellulose which is a non-ionic derivative of cellulose with hydroxyethyl groups attached to the polymer structure. Resistant to high pressures and temperatures, which can be used for drilling, completion and repair of oil wells.

BACKGROUND The present invention relates to the composition, method of preparation and application of a fluid product, formulated with a mixture of Hydroxyethyl Cellulose which is a non-ionic derivative of cellulose with hydroxyethyl groups attached to the polymer structure. Resistant to high pressures and temperatures, which can be used for drilling, completion and repair of oil wells, and more specifically to drill, finish and repair the area producer of offshore, terrestrial and lacustrine wells, producers of hydrocarbons (crude oil, gas and oil-gas mixtures and condensates.) The invention has the peculiarity of significantly reducing the damage to the permeability of water-soluble production formation for provide the characteristics of density, polymers and special additives to provide the product with the physicochemical properties that all drilling fluid, completion and repair of wells require to fulfill its functions, and above all to provide a thermal resistance of 85 ° C up to 120 ° C lubricating the production formation A primary feature of the present invention is the composition that integrates the drilling fluid / completion / repair of oil wells is to increase the viscosity and control the losses by filtration that do not require great times, high cutting speeds or heating, turning it into a prod uctor highly friendly with the environment.

Specifically, the present invention relates to compositions containing liquid polymer for use as a thickening agent to make viscous brines and provide thick fluids. Hydroxyethylcellulose, Nonionic Cellulose Ether, [(C6H905) (C2H0) xH] n, is a thickener and suspending agent. It is obtained from the reaction of cellulose with caustic soda and ethylene oxide. As well as DPM Glycoeter, Quaternary Amine, Tall Oil Fatty Acids and Methanol.

For the drilling of an oil well it is necessary to use a fluid (traditionally known as mud) which can be water base, oil base or a gas in order to carry out multiple functions. This fluid must, among other things, counteract the pressures of the drilling fluids, cool and lubricate the auger, carry the perforated cuttings to the surface for their separation and be recycled, after conditioning, to reintroduce it to the well itself.

During the drilling operations, different formations (shales, sands, sandy shales, limestones, marls, shales, shales) are traversed before reaching the formation containing the hydrocarbons that have to be extracted for commercialization. Usually the deposits where the hydrocarbons are located consist of carbonated rocks, sands and / or sandy shales, which by virtue of their permeability can allow said hydrocarbons to flow naturally taking advantage of the existing pressures in the reservoirs or to be depressed deposits. which require the use of secondary recovery techniques (pneumatic pumping, mechanical pumping, electro-centrifugal pumping.). Invariably, the flow of hydrocarbons through the porous medium will depend greatly on whether the insoluble particles of the traditional drilling fluids have invaded said zones, causing, among other causes, the clogging of the pores of the formation, and with this the reduction of hydrocarbon production. »'Permeability is the ease with which the pores of the formation can allow the free flow of a fluid through them, which will depend to a large extent on how well the pores are communed with each other and that there are no particles foreign to the formation that prevent or block the passage of fluids through it, This process of invasion or blockage of the pores of the formation is traditionally known as damage to the production formation, which is caused by the fluids used during the drilling, completion or repair of oil wells.

The solids contained in traditional drilling fluids are generally insoluble solids in water and oil, which, when drilling, invade the production formation, causing the formation pores to clog and thus reducing their permeability. The chem nature of these solids (normally Densifying agents such as barite, ilmenite, galena, iron oxide) prevents them from being dissolved by traditional treatment with 15% HCI causing irreversible damage to the permeability of the formation.

To solve the problems of damage to the production formation we have been using fluids formulated based on heavy brines free of solids, which present the advantage that they do not require insoluble solids (such as barite, calcium carbonate, iron oxide, galena .) to increase the density that high pressure high temperature wells require for the control of formation pressures, this type of fluid increases its density by dissolving salts or salt mixtures (NaCl, KCI, CaCl2, CaBr2, ZnBr2, NaHCO3, NaBr, KHC03, NaHC03, NH4CI, among others) in water, in such a way that there are no insoluble solids (in suspension) that could, during the drilling of the producing zone, invade the formation with the consequent tamponade and reduction of permeability and well production.

Hydroxyethylcellulose powder presents several problems at the time of pouring into oil wells, which requires mixing properly with another additive that allows its maneuverability, adding the preparation time it takes to be used even in many of the occasions come to be lumps or fish eyes which hinders or impedes the specific function of providing a higher viscosity of the brines.

They can be taken as references of existing patents in the market in synthetic and water-based liquid versions such as: The patent WO 2012131417 A1: The synthetic polymer of the invention is used as a viscosifier and filtering reducer of divalent simple and binary brines and has the characteristic that it does not require prolonged stirring, heating or use of high cutting speeds to hydrate in the presence of high density divalent brines. This novel polymer also has a thermal resistance higher than 200 ° C and is used in a concentration range of 1.0 to 40 kg / m3, and more preferably 0.5 to 20 kg / m3, characterized in that it is a polymer of a molecular formula ( C8H 6CIN) no (C6H14CIN) n, selected from the group of azaciclopetano, azolidina, prolamine, tetramethylenediamine, tetrahydropyrrole, butyleneamine, pyrrolidine, piperidine or their mixtures and / or because the filtrate reducing viscosifier of the invention can also be derived from one or more of the following homopolymers: N, N Dimethyl-N-2 Propenyl Chloride -2propen amino, 2 propen-1 -amino NN- chloride Patent EP 0413274 B1, is an aqueous suspension comprising 8 to 28%, by weight of the total suspension, of water-soluble hydroxyethylcellulose (HEC) dispersed in an aqueous solution comprising 20 to 35%, by weight of the total carbonate of potassium and water, of potassium carbonate, 0.2 to 0.8%, by weight of the total suspension, of a wetting agent having an HLB of 6 to 9, and 0.08 to 0.6% , by weight of the total suspension, of a water soluble or swellable in thickener water. The suspension further comprises 0.05 to 0.5% by weight of a dispersing agent having an HLB greater than 14. This invention is also directed to a process for preparing such a suspension and a process for preparing a HEC aqueous solution dissolved using a suspension of this type.

WO 9713578: The present invention is directed to a dispersion of polymer, water-soluble, oil-free liquid, for use in the thickening of aqueous media, in particular, determination and reconstruction fluids used in the gas drilling business. and Petroleum The dispersions of the present invention are comprised of hydroxyethyl cellulose and propylene glycol derivatives, preferably propylene glycol polyester and aliphatic ether of low toxicity, these dispersions include water. Due to its drilling in offshore environments. These compositions rapidly disperse and viscosify a variety of salt flats, including seawater and other light salt, with a minimum of cizal and without the formation of fish eyes.

DETAILED DESCRIPTION OF THE INVENTION Hydroxyethylcellulose is a non-ionic derivative of cellulose with hydroxyethyl groups attached to the polymer structure. Which provides rheology, bacterial resistance, works in any type of salinity, does not contain biosides. Avoid developing high gels in its formulation.

Hydroxyethylcellulose, is a polymer of cellulose and ethylene, which forms a viscous gel soluble in water and in ethanol, can be used in substitution carboxymethylcellulose or CMC, fulfilling a function similar to this, giving results of resistance to temperatures of 85 ° C until 120 ° C.

Glycoeter DPM, is a strong solvent, which is used as dispersion medium for hydroxyeticellulose ,.

The quaternary amine is a positively charged polyatomic ion, of structure NR4 +, R starting from an alkyl group or an aryl group. TO Unlike the ammonium ion (NH4 +) and the primary, secondary or thematic ammonium cations, the quaternary ammonium cations are permanently charged, regardless of the pH of their solution. Salts of quaternary ammonium cations linked to an anion.

Fatty acids derived from Tall Oil, is a yellowish liquid, with a characteristic odor, obtained as a by-product in the manufacture of paper pulp, from coniferous, by the Kraft process, also called liquid resin, is obtained starting from the black liquor waste from the manufacture of cellulose pulp by alkaline processes and, more especially, by the sulphate process. It is a liquid consisting essentially of a mixture of fatty acids and resin acids.

Methanol, also known as methyl alcohol or wood alcohol. At room temperature it appears as a light liquid (low density), colorless, flammable and toxic that is used as a solvent, its chemical formula is CH40.

In order to obtain the non-ionic hydroxyethyl cellulose object of the present invention, it is necessary that its elements have the following degree of concentration: hydroxyethylcellulose of 80% to 99%, preferably 99%; fatty acids derived from tall oil from 80% to 99%, preferably 99%, glycoether DPM from 80% to 100%, preferably 100%; Methanol 70% to 100%, preferably 100%; Quaternary amine from 80% to 99%, preferably 99%.

The present invention has a boiling point of 85 ° C to 120 ° C TCC, ASTM D56; Pour point -37.2 ° C; Freezing Point -42.7 ° C; Density 8.07 Ib / gal; Specific gravity (SG) 0.970. Giving a cream-colored appearance.

EXAMPLE 1. Preferred obtaining method of the present invention: The following are introduced: 99% DPM glycoether + fatty acids derived from Tall 0/7 at 99% + 100% methanol + 99% Quaternary amine, in a mixer; once said components are introduced, said mixer is ignited and stirring starts at 1000 rpm, until the integration of the components is observed a viscous texture, then the hydroxyethylcellulose powder is added, preferably at 99%, additionally the mixer by agitation, it is increased to 2000 rpm, to ensure that no lump or fish eye remains, and agitation is maintained, to obtain the nonionic hydroxyethylcellulose, which is a suspension, viscous in cream color, stable and manageable at room temperature to finally obtain the nonionic hydroxyethyl cellulose object of the present invention.

The nonionic hydroxyethylcellulose will not undergo the dehomogenization of the elements when it is at rest or storage, due to the mixing system by agitation, which in other liquid products, happens the separation of the elements when at rest. Making a unique suspension, eliminating the sedimentation of pure polymeric solids Hydroxyethylcellulose, converting it into a fully pourable compound. This allows an efficient handling to make quick mixes and sweeps without the need of mixer equipment, to pour it into the oil well.

EXAMPLE 2. Preparation of 1 liter of hydroxyethyl cellulose The amount of the components that are used to prepare 1 liter of the present invention are detailed in table 1.

Table 1. Amount of elements used in the 1 liter preparation of the present invention.

The present invention comprises 40% of hydroxyethylcellulose which together with the rest of the elements that make up the formula provide a liquid state for brines in high density, making it not degrade by common bacteria.

Providing a pseudoplastic rheology not allowing to develop high gels. Making a product easy to handle, increasing the volume of the fluids facilitating their extraction, working in any type of salinity and does not require biosides.

EXAMPLE 3. Method of Application of the invention The fluids that are used in the drilling of a well are administered by the so-called circulation system and injection treatment. The system is composed of intercommunicated tanks that contain mechanisms such as: sieves / s: mechanical device, first in the drilling fluid cleaning line, which is used to separate trepan cuttings or other solids found in the same in his return from the well. The fluid passes through one or several vibrating strainers of different meshes or size of holes that separate the larger solids; the degasser / is; Desander / developer The fluid is pumped tangentially through the interior of one or more cyclones, cones, within which the rotation of the fluid provides sufficient centrifugal force to separate the dense particles by effect of their weight. The mixing funnel or hopper that is used to add dusty additives or suspensions to the drilling fluid and the centrifugal pumps and piston pumps (2 or 3): they are responsible for receiving the injection prepared or reconditioned from the tanks and push it inside of the drilling column through the passage or passages of the trephine and returning it to the surface by the resulting annular space between the drill string and the wall of the well, loaded with the cuttings of the trephine, and contaminated by the components of the traversed formations. Drilling fluids; Its design and composition are established according to the physico-chemical characteristics of the different layers to be traversed. The qualities of the selected fluid depends on the density, viscosity, pH, filtering, chemical composition, they must contribute to fulfill the different functions of the same, such as cooling and cleaning the trepan; carry the cuts that generate the action of the trepan, care of the environment.

EXAMPLE 4. Evaluation of the viscosity of the non-ionic hydroxyethyl cellulose Table 2 shows the different degrees of viscosity that non-ionic hydroxyethylcellulose acquires, when exposed to temperatures, and reaction to a brine of 3% ammonium chloride and in saturated sodium chloride brine. As the quantities to be used, enter the number of liters of nonionic hydroxyethylcellulose, by the cubic meters of brine, to be poured into the oil well. As well as the revolutions to which the samples are subjected are shown to check the result of the degree of viscosity exposed to a certain temperature.

Table 2. Viscosity of a Hydroxyethylcellulose solution in suspension form in Brine 3% Ammonium Chloride Temp ° C 600 300 200 100 6 3 |;; |, · Hydroxyethylcellulose in suspension: 14.1 liters per 3,785m3 23. 9 25 17 13 9 5 2 37. 8 19 13 9 7 4 1 51. 7 14 9 7 5 3 1 65. 55 10 6 5 4 2 1 Table 3. In the same condition as table 2, the viscosity of non-ionic hydroxyethylcellulose is shown, at the moment it is exposed in a saturated sodium chloride solution.

Table 4. It shows the tests made of corrosivity, reactivity, explosivity, toxicity, inflammability, biological infectious.

Table 4. Analyzes carried out to demonstrate the maximum minimum levels of the compound.

PROOF TEST CONDITIONS OBSERVATIONS Determination of pH 7.8 pH (< 2 &> 12.5 corrosive) Negative Corrosivity Corrosion veil, mm / year NA Corrosion velosity, mm / year (> 6.35 corrosive) Negative At 25 ° C and 1 atmosphere is combined or plome curl Negative At 25 ° C and 1 atmosphere (Residue-Water) of 5: 1 Negative At 25 ° C and 1 atmosphere (Residue-Water) of 5: 3 Negative At 25 ° C and 1 atmosphere (Residue-Water) of 5: 5 Negative At 25 ° C and 1 atmosphere (Residue - HCI 1.0 N) of 5: 1 Negative At 25 ° C and 1 atmosphere (Residue-HCI 1.0 N) of 5: 3 Negative At 25"C and 1 atmosphere (Residue-HCI 1.0 N) of 5: 5 Negative At 25 ° C and 1 atmosphere (Residue-NaOH 1.0 N) of 5: 1 Negative Reactivity At 25 ° C and 1 atmosphere (Residue-NaOH 1.0 N) of 5: 3 Negative At 25 ° C and 1 atmosphere (Residue-NaOH 1.0 N) of 5: 5 Negative Gases, Vapors, or Fumes in conditions of pH 2.0 Negative Gases, Vapors, or Fumes in conditions of pH 4.0 Negative Gases, Vapors, or Fumes in conditions of pH 7.0 Negative Gases, Vapors, or Fumes in conditions of pH 9.5 Negative Gases, Vapors, or Fumes in conditions of pH 12.5 Negative It is layers of producing free radicals Negative Explosivity ICD of explosivity = To dinitrobenzene Negative At 25 ° C and 1.03 Kg / cm2 of pressure suffers explosive reaction Negative Toxicity Exceeds the limits of tables 5,6 and 7 of the Negative standard In non-aqueous contains > 24% alcohol in volume Negative Flash point, ° C NA If it is liquid (flash point < 60"C, flammable Negative Flammability It is not liq. And it causes fire by friction. Negative It is not liq. And causes fire by moisture absorption Negative At 25 ° C and 1.03 Kg / cm2 it undergoes chemical changes. Negative spontaneous They are gases or oxidants stimulants of Negative combustion Content of total coliform bacteria / gr Absent Biological Content of fecal coliform bacteria / gr Absent Infectious Biological risk and negative fertility Test method: Cretib (NOM-052-ECOL 1993) The data shown in the various tests done, the results are show, absent, negative and in some cases does not apply.

Claims (26)

CLAIMS Having described my invention enough, I consider it as a novelty and therefore claim as my exclusive property, what is contained in the following clauses:

1. Non-ionic hydroxyethyl cellulose characterized in that it comprises hydroxyethylcellulose from 35% to 50% w / v ratio, from 50% to 99% purity; fatty acids derived from tall oil from 1% to 8% v / v ratio, from 50% to 99% pure; DPM glycoetic from 40% to 60% v / v ratio, from 50% to 99% purity; methanol from 1% to 5% v / v ratio, from 50% to 100% purity and quaternary amine from 1% to 8% v / v ratio, from 50% to 99% purity.

2. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it preferably comprises hydroxyethyl cellulose; at 40% ratio p / v to 99% purity; fatty acids derived from tall oil at 2% v / v ratio, at 99% purity; DPM glycoet 53% v / v ratio, 99% pure; methanol of 1% v / v ratio, at 100% purity; quaternary amine 4% ratio v / v to 99% purity.

3. Non-ionic hydroxyethyl cellulose, according to claim 2, characterized in that it comprises hydroxyethylcellulose in 53% ratio w / v.

4. Non-ionic hydroxyethyl cellulose, according to claim 3, characterized in that it comprises 99% pure hydroxyethylcellulose.

5. Non-ionic hydroxyethyl cellulose, according to claim 2, characterized in that it comprises fatty acids derived from tall oil at 2% v / v ratio.

6. Non-ionic hydroxyethyl cellulose, according to claim 5, characterized in that it comprises fatty acids derived from tall oil in 99% purity.

7. Non-ionic hydroxyethyl cellulose, according to claim 2, characterized in that it comprises glycerol DPM in 53% v / v ratio.

8. Non-ionic hydroxyethyl cellulose, according to claim 7, characterized in that it comprises 99% purity GMP glycoether.

9. Non-ionic hydroxyethyl cellulose, according to claim 2, characterized in that it comprises methanol in 1% v / v ratio.

10. Non-ionic hydroxyethyl cellulose, according to claim 9, characterized in that it comprises 100% pure Methanol.

1 1. Non-ionic hydroxyethyl cellulose, according to claim 2, characterized in that it comprises Quaternary amine in 4% v / v ratio.

12. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it comprises 99% pure Quaternary Amine.

13. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it has a pour point at -37.2 ° C.

14. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it has a Freezing point at -42.7 ° C;

15. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it has a density of 8.07 Ib / gal.

16. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it has a specific gravity (SG) of 0.970.

17. Hydroxyethyl non-ionic cellulose, according to claim 1, characterized in that its viscosity at 26.6 ° C in the form of saturated sodium chloride brine suspension is 58.

18. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that it has a viscosity at 26.7 ° C in the form of suspension of 3% ammonium chloride brine is 25.

19. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its corrosivity test, is within the normal range.

20. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its reactivity test are within the normal range.

21. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its explosion test are within the normal range.

22. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its toxicity test, is within the normal range.

23. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its flammability test, is within the normal range.

24. Non-ionic hydroxyethyl cellulose, according to claim 1, characterized in that the results of its infectious biological test are within the normal range.

25. Non-ionic hydroxyethyl cellulose, according to claims 1 to 24, characterized in that it is obtained by the introduction of DPM glycoether, fatty acids derived from Tall 0/7, Methanol, Quaternary amine, in a mixer; Once these components are introduced, the mixer is turned on and the stirring starts at 1000 rpm, until the integration of the components shows a viscous texture, the hydroxyethylcellulose powder is added later, the mixer is added by agitation to 2000 rpm, to ensure that no lump or fish eye remains, and agitation is maintained, to obtain the nonionic hydroxyethylcellulose, which is a suspension, viscous in cream color, stable and manageable at room temperature to finally obtain hydroxyethyl cellulose not ionic

26. Use of the non-ionic hydroxyethyl cellulose according to claims 1 to 24 as a suspension for the drilling, completion and repair of oil and gas wells