EP-4735553-A1 - HIGH-DENSITY, SUB-ZERO STABLE CLEAR LIQUID COMPOSITION AND THE METHOD FOR PRODUCING THEREOF

Abstract

The invention relates to a liquid composition which is essentially clear and comprises at least one alkali metal phosphate salt in a liquid, further comprising at least one additional component, preferably a carboxylic acid, and discloses the production method thereof. The liquid composition is adapted for the use as a well drilling, completion, and workover fluid, mining fluid, deicing agent and heat transfer fluid and furthermore features a range of desirable properties, including high and low temperature tolerance, low toxicity, low corrosiveness, and high compatibility with formations.

Inventors

• BRENDLER, Lucas
• Brendler, André
• BRENDLER, Tuula

Assignees

• SAMPOCHEM GMBH

Dates

Publication Date

20260506

Application Date

20240627

Claims (20)

1. 1. A liquid composition, wherein the composition is essentially clear and comprises at least one alkali phosphate salt in an aqueous solution, wherein the alkali phosphate salt comprises a potassium counter cation, characterized in that the composition comprises at least one additional component, wherein the additional component is a solubilizing agent, which increases the solubility of the alkali phosphate salt, wherein the additional component is a carboxylic acid RCO2Y, wherein the carboxylic acid RCO2Y is a hydroxy acid, wherein the acid is provided in its free form and/or its alkali salts and/or its cyclic esters and/or its anhydrides, wherein R is an optionally substituted Ci to Ce linear, branched or cyclic alkyl group or an optionally substituted aryl group, wherein the total solids in solution are between 10% to 90% by weight of the composition.
2. 2. Composition according to claim 1 , wherein the additional component is a sugar acid and/or its derivates
3. 3. Composition according to claim 2, wherein the sugar acid and/or its derivates is a gluconic acid and/or its alkali salts and/or its cyclic esters and/or its anhydrides
4. 4. Composition according to any one of the claims 1 to 3, wherein the alkali phosphate salt comprising a potassium counter cation is selected from the list consisting of dipotassium phosphate and/or, tripotassium phosphate and/or potassium pyrophosphate.
5. 5. Composition according to any one of the claims 1 to 4, wherein the additional component is added in a fraction between 1 % to 30% of the alkali phosphate salt.
6. 6. Composition according to any one of the claims 1 to 5, wherein the average protonation rate of the alkali phosphate salt is between 0% to 33%.
7. 7. Composition according to any one of the claims 1 to 6, wherein the composition has a density between 1 20 g/cm 3 and 2.40 g/cm 3 as a clear solution at 20°C.
8. 8. Composition according to any one of the claims 1 to 7, wherein the composition has a pH value in the range of 7.0 to 13.0.
9. 9. Composition according to any one of the claims 1 to 8, wherein the working temperature of the liquid, where it does not precipitate or thermally degrade, is between -20 to 180 °C.
10. 10. Composition according to any one of the claims 1 to 9, wherein the liquid composition does not form precipitates when stored at a temperature of at least -5 °C to room temperature.
11. 11. Composition according to any one of the claims 1 to 10, wherein the liquid composition is a clear liquid with an NTU less than 40.
12. 12. Composition according to any one of the claims 1 to 11 , wherein the liquid composition comprises at least one further component, such as corrosion inhibitors, viscosity-enhancing agents, surfactants, pH stabilizers, biocides, and clay inhibitors.
13. 13. Composition according to any one of the claims 1 to 12, wherein the composition exhibits minimal impact to its environment, specifically inhibiting a low EC50 value between 50 and 250 g/L.
14. 14. Composition according to any one of the claims 1 to 13, wherein the liquid composition exhibits specialized drilling features, such as low corrosiveness to drilling equipment and periphery infrastructure with a corrosion rate of less than 0.01 mm/yr, a good inhibition performance with clay minerals, with an retention rate of 98%, and high compatibility with formation water.
15. 15. A method for preparing a composition according to any one of the claims 1 to 14, wherein the liquid composition is made in-situ by a) formulating an alkali phosphate solution under stirring b) adding an additional component under stirring, c) then cooling the solution to obtain a liquid composition in accordance with any of the claims 1 to 14.
16. 16. Method according to claim 15, wherein said composition is heated after the addition of the additional component (step b) to 70-120 °C for less than one hour.
17. 17. Method according to any one of the claims 15 or 16, where the alkali phosphate solution from claim 15, a) is prepared from alkali phosphate salts and/or aqueous alkali phosphate salt solutions and/or by reacting basic alkali metal salts, and phosphor-based acids, selected from phosphoric acids and/or orthophosphoric acid.
18. 18. Method according to claim 17, wherein the stoichiometric ratio between phosphor-based acids and basic alkali metal salts is in the range of 0.1 to 1 5.
19. 19. Method according to any claims 15 to 18, wherein said composition is stirred in total for up to 120 minutes.
20. 20. A method for preparing a solid form of the composition according to any one of the claims 1 to 14 by a) drying the liquid composition according to any one of the claims 1 to 14 at temperatures around 100°C until the water content is less than 10% w/w, b) grinding the solid composition to obtain a free flowing solid, thus yielding a solid form of the liquid composition according to any one of the claims 1 to 12.

Description

HIGH-DENSITY, SUB-ZERO STABLE CLEAR LIQUID COMPOSITION AND THE METHOD FOR PRODUCING THEREOF TECHNICAL AREA The present invention pertains to a novel and economical liquid composition according to claim 1. The liquid composition relates to a high-density, sub-zero stable liquid devoid of solids used as a well drilling, completion, and workover fluid, mining fluid, deicing agent and heat transfer fluid featuring a range of desirable properties, including high and low temperature tolerance, low toxicity, low corrosiveness, and high compatibility with formations and discloses the production method thereof. STATE OF THE ART In the drilling, completion, and workover of oil and gas wells as well as in mining operations, fluids known as drilling fluids are utilized to achieve various functions, including: Lubrication to reduce friction between the drill bit and the formation, increasing drilling efficiency and reducing wear and tear on drilling equipment; cooling to dissipate heat generated by friction and prevent overheating of drilling equipment; suspension to transport solids from the formation to the surface and prevent solid buildups in the wellbore; weight control to provide adequate downward pressure on the drill bit to prevent wellbore collapse; formation stability to preserve the integrity of the wellbore by preventing collapse or formation sloughing during drilling; and corrosion protection to prevent corrosion of drilling equipment and preserve the wellbore. Drilling, completion, and workover fluids, also known as well-servicing fluids, can be broadly classified into two categories: traditional and solid-free. Traditional well-servicing fluids include solid weighting agents, such as barite, bentonite, and hematite, to increase fluid density and counteract high formation pressures. On the other hand, solid-free well-servicing fluids with a NTU less than 40 are clear or nearly clear liquids without any solid components and are generally gentler on the formation, reducing the risk of damage compared to traditional fluids. Alkali and alkaline earth metal and some transition metal salt solutions, alone or in combination, are commonly utilized in oil and gas well drilling, completion, workover, packer, and perforation. The introduction of solid-free, so called clear-brine fluids has significantly enhanced completion and workover operations by reducing formation plugging and solids settling issues that were previously encountered with traditional water-based or oil-based drilling fluids Solid-free, clear brine fluids are an advantageous choice for oil and gas well servicing and completion due to the following unique properties: the elimination of solid partid es eliminates formation plugging and solids settling issues associated with water-based or oil-based drilling fluids; the inhibition of clay swelling and dispersion in porous media; the preservation of subterranean formation wettability; the reduced corrosiveness to drilling equipment; and the relatively high density and chemical compatibility with the formation The formula of a solid-free well-servicing fluid typically includes various components such as the solvent water, soluble weighting materials, corrosion inhibitors, viscosity-enhancing agents, surfactants, pH stabilizers, biocides, and clay inhibitors. Weighting materials, which contribute to the density of the fluid, are particularly significant as they can make up a substantial amount of the fluid's mass, thus greatly affecting the performance of the solid-free well-servicing fluid When completing a well in a reservoir with a normal pressure system, a low-density brine can be used. However, in reservoirs with abnormally high pressure, a high-density brine is necessary. Despite the need for a high-density fluid, it can be difficult to attain densities above 1 .80 g/cm3 with a solid-free completion fluid, as there are no solid weighting particles in the liquid Besides the challenge of maintaining the correct fluid density, many conventional clear brine drilling fluids including halide, phosphate and formate brines encounter technical, environmental, or economic constraints that make them unsuitable for specific well conditions Clear brine fluids have garnered significant attention due to their distinctive properties that make them useful in a variety of applications beyond their use in the oil, gas, and mining industry, resulting in the replication or adaptation of these products for other sectors. In particular, their high density and low freezing points make them highly effective as deicing agents for industries such as construction, aviation, and transportation, where cold temperatures and snowfall can hinder or halt operations and lead to safety concerns. These fluids can quickly melt existing ice and prevent the formation of new ice, making them ideal for use on airports, highways, and walkways in cold environments. Clear brine fluids also have exceptional heat transfer properties, making th