A method for preparing environmentally friendly drilling fluid base fluid

Abstract

The invention discloses a method for preparing an environmentally friendly drilling fluid base liquid, and belongs to the technical field of organic chemical industry. The method obtains a drilling fluid base liquid product by performing steps such as petroleum heating distillation, hydrocracking, isomerization dewaxing, hydrofining, composite molecular sieve treatment and molecular distillation. The drilling fluid base liquid product has low contents of cycloalkanes and chain alkanes, high content of isoalkanes, low biological toxicity, and can meet relevant requirements of marine biological toxicity tests. The preparation technology realizes the nationalized production of drilling fluid base liquid.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemical industry, and in particular relates to a method for preparing an environmentally friendly drilling fluid base fluid. Background Art

[0002] At present, the domestic drilling fluid used in offshore drilling platforms needs to meet the requirements of marine biological toxicity tests. High-purity isoalkanes contain almost no harmful impurities, basically no odor, high chemical stability, long product shelf life, easy recycling and reuse, good comfort and safety. Moreover, the flash point and volatility of narrow-fraction isoalkanes are consistent, and the application effect in professional fields is better, which meets the relevant needs of drilling fluids.

[0003] The patent application with patent publication number CN116396136A discloses a method for preparing bio-based isoalkanes. In addition to using waste edible animal and plant oils and fats that have been refined and impurities removed, fatty acid methyl esters obtained by ester exchange and esterification of acidified oil, fatty acids and methanol are used as raw materials. This method uses hydrogenation isomerization, molecular sieve adsorption and / or urea complex separation to obtain isoalkanes with high efficiency, high yield and few side reactions. However, the raw material processing is relatively complicated and the cost is high, and mineral oil is not used as the raw material.

[0004] The patent application with patent publication number CN101921621A discloses a method for preparing isoparaffin solvent oil by using petroleum-based distillate oil or deasphalted oil as raw materials and adopting a hydrogenation pre-refining-hydroisomerization process; since the petroleum-based raw oil contains a large amount of harmful compounds such as sulfur, nitrogen, aromatics, etc., which cannot be completely removed, the purity of the product is affected, and the product is mainly a light isoparaffin solvent oil fraction with a yield of more than 60%.

[0005] There is no relevant literature in the prior art on the relevant research technology of refining petroleum as base oil and obtaining high-purity isoparaffins at the same time. In order to protect the ecological environment and meet the needs of marine drilling, the use of low-toxic oil-in-water emulsion drilling fluid with mineral oil as base oil is the current technological development trend. It is urgent to develop an environmentally friendly drilling fluid base fluid with mineral oil as base oil. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing an environmentally friendly drilling fluid base fluid, wherein the obtained drilling fluid base fluid has low cycloalkane and chain alkane contents, high isoalkane content and low biological toxicity.

[0007] The content of the present invention includes:

[0008] A method for preparing an environmentally friendly drilling fluid base fluid, wherein the carbon number of the drilling fluid base fluid is C11 to C16, and the preparation method comprises the following steps:

[0009] (1) Heating the petroleum to between 400°C and 500°C, turning it into steam, and then passing it into a fractionation tower, selecting the fraction at 230°C to 380°C as the crude product of the drilling fluid base fluid;

[0010] (2) passing the crude product obtained in step (1) into a hydrocracking reactor for hydrocracking treatment to obtain a semi-finished product;

[0011] (3) passing the semi-finished product obtained in step (2) into an isomerization dewaxing reactor for isomerization dewaxing treatment, wherein the reaction zone of the isomerization dewaxing reactor is filled with an isomerization dewaxing catalyst;

[0012] (4) passing the dewaxed product of step (3) into a hydrotreating reactor for hydrotreating treatment to obtain a refined product, wherein the reaction zone of the hydrotreating reactor is filled with a hydrotreating catalyst;

[0013] (5) passing the product after purification in step (4) through a composite molecular sieve for treatment;

[0014] (6) The refined product obtained in step (5) is passed into a preheating furnace for preheating, and the preheated refined product is sequentially passed into a molecular distiller for molecular distillation to obtain a heavy fraction and a light fraction, and the heavy fraction is selected as the drilling fluid base fluid product.

[0015] Furthermore, the composite molecular sieve is a SAPO-11 / ZSM-22 composite molecular sieve, and the mass ratio of SAPO-11 to ZSM-22 is 3:1.

[0016] Furthermore, in step (6), the operating pressure of the molecular distiller is 10-100 Pa, and the reaction temperature is 50-80°C.

[0017] Furthermore, in the step (2), the reaction zone of the hydrocracking reactor is filled with a first hydrocracking catalyst and a second hydrocracking catalyst having different cracking activities, and the operating pressure in the hydrocracking reactor is 14-16 MPa, and the reaction temperature is 380-400° C.;

[0018] The first hydrocracking catalyst and the second hydrocracking catalyst are both supported non-precious metal catalysts, and the supported non-precious metal catalysts contain a first carrier and a carrier, wherein the first carrier contains at least one Group VIII metal element and at least one Group VIB metal element.

[0019] Furthermore, the content of the Group VIII metal element is 1 to 10 wt% of the total amount of the first hydrocracking catalyst, and the content of the Group VIB metal element is 5 to 50 wt% of the total amount of the first hydrocracking catalyst; the content of the Group VIII metal element is 1 to 10 wt% of the total amount of the second hydrocracking catalyst, and the content of the Group VIB metal element is 5 to 50 wt% of the total amount of the second hydrocracking catalyst.

[0020] Furthermore, the VIB group metal element is molybdenum and / or tungsten; the VIII group metal element is cobalt and / or nickel; and the first carrier is selected from one or more of γ-alumina, silicon oxide, alumina-silicon oxide, titanium oxide, and magnesium oxide.

[0021] Furthermore, the cracking activity of the first hydrocracking catalyst is greater than that of the second hydrocracking catalyst, and the packing volume ratio of the first hydrocracking catalyst to the second hydrocracking catalyst is 1:5 to 5:1.

[0022] Further, the isomerization dewaxing catalyst is a supported single-atom noble metal catalyst, which contains a second carrier and a single-atom noble metal supported on the second carrier;

[0023] The second carrier is a molecular sieve or an alumina carrier;

[0024] The single-atom noble metal is selected from one or more of platinum, palladium, ruthenium, rhodium, iridium, gold or silver;

[0025] The weight content of the monatomic noble metal in the isomerization dewaxing catalyst is 0.1-1.0%.

[0026] Furthermore, the second carrier is a ZSM-12 molecular sieve or a ZSM-11 molecular sieve or a ZSM-12 / ZSM-11 composite molecular sieve.

[0027] Furthermore, the hydrotreating catalyst is a supported single-atom noble metal carrier, which contains a third carrier and a single-atom noble metal supported on the third carrier;

[0028] The third carrier is an alumina carrier;

[0029] The single-atom noble metal is selected from one or more of platinum, palladium, ruthenium, rhodium, iridium, gold or silver.

[0030] Beneficial effects of the present invention:

[0031] (1) The present application adopts lubricating oil hydrogenation technology, that is, crude oil fractions are subjected to hydrocracking-isomerization dewaxing-post-refining joint production technology to produce light components with high saturated hydrocarbon content, and then the isoparaffin components are selected through molecular sieves, and then molecular distillation is performed for cutting (preheating furnace, molecular distillation tower, fractionation tower and product storage tank) to remove the light components. Such drilling fluid base liquid has a more concentrated carbon number distribution and low biological toxicity;

[0032] (2) The selected composite molecular sieve SAPO-11 / ZSM-22 effectively removes some straight-chain alkanes and cycloalkanes in the product, further improving the isomerization of the product. The composite molecular sieve has a good separation effect of normal and isoalkanes;

[0033] (3) preheating in the preheating furnace of step (6), and then performing molecular distillation treatment, with appropriate reaction temperature and operating pressure, to further separate the heavy fraction and the light fraction, so that the obtained drilling fluid base fluid product has higher purity;

[0034] (4) The isodewaxing treatment step of step (3) isomerizes straight-chain alkanes into branched alkanes, lowers the freezing point, and the selection of the isodewaxing catalyst further increases the conversion rate of normal alkanes into isoalkanes. DETAILED DESCRIPTION

[0035] Example 1

[0036] A method for preparing an environmentally friendly drilling fluid base fluid comprises the following steps:

[0037] (1) Heating the oil to 450°C, turning it into steam, and then passing it into a fractionation tower, selecting the fraction at 230°C to 380°C as the crude product of the drilling fluid base fluid;

[0038] (2) passing the crude product obtained in step (1) into a hydrocracking reactor for hydrocracking treatment to obtain a semi-finished product, wherein the hydrocracking reactor is filled with a first hydrocracking catalyst of 5% NiO-30% MoO3 / TiO2 catalyst and a second hydrocracking catalyst of 5% NiO-20% MoO3 / Al2O3 catalyst, and the filling volume ratio of the first hydrocracking catalyst to the second hydrocracking catalyst is 1:5;

[0039] (3) passing the semi-finished product obtained in step (2) into an isomerization dewaxing reactor for isomerization dewaxing treatment at a pressure of 15 MPa and a reaction temperature of 400° C., wherein the reaction zone of the isomerization dewaxing reactor is filled with 180 ml of a 0.5% isomerization dewaxing platinum-based catalyst with a ZSM-12 molecular sieve as a carrier;

[0040] (4) passing the semi-finished product after dewaxing in step (3) into a hydrofining reactor for hydrofining treatment to obtain a refined product, wherein the reaction zone of the hydrofining reactor is filled with 0.5% of a platinum-based alumina catalyst;

[0041] (5) passing the refined product of step (4) into two fixed-bed adsorption separation reactors connected in series and filled with SAPO-11 / ZSM-22 composite molecular sieves with a mass ratio of 3:1 for adsorption separation of normal and iso-alkanes; the pore size of the main pore of the SAPO-11 molecular sieve is concentrated at 0.60 nm, the pore opening is elliptical, and the ten-membered ring one-dimensional straight pore; ZSM-22 has a topological skeleton of TON structure, and the skeleton structure contains five-membered rings, six-membered rings and ten-membered rings at the same time, wherein the one-dimensional pores composed of sixteen rings are parallel pores that are not cross-linked, and the pore opening is elliptical;

[0042] (6) The refined product obtained in step (5) is passed into a preheating furnace for preheating, and the preheated refined product is sequentially passed into a molecular distiller for molecular distillation treatment at a pressure of 80 Pa and a reaction temperature of 60° C. to obtain a heavy fraction and a light fraction; the heavy fraction is selected as the drilling fluid base fluid product.

[0043] Example 2

[0044] The loading volume ratio of the first hydrocracking catalyst to the second hydrocracking catalyst in step (2) is 2:3, and the rest is the same as in Example 1.

[0045] Example 3

[0046] The molecular distillation treatment in step (6) has a pressure of 50 Pa and a reaction temperature of 80° C., and the rest is the same as in Example 1.

[0047] Comparative Example 1

[0048] The molecular sieve in step (5) was changed to SAPO-11 molecular sieve, and the rest was the same as in Example 1.

[0049] Comparative Example 2

[0050] The molecular distillation treatment in step (6) is placed before step (5), and the rest is the same as in Example 1.

[0051] Comparative Example 3

[0052] Remove step (3), and the rest is the same as in Example 1.

[0053] The test results of the drilling fluid base fluid products obtained in Examples 1-3 and Comparative Examples 1-3 are as follows:

[0054]

[0055]

[0056] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0057] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing an environmentally friendly drilling fluid base fluid, characterized in that: The carbon number of the drilling fluid base fluid is C11-C16, and the preparation method comprises the following steps: (1) Heating the petroleum to between 400℃ and 500℃, turning it into steam, and then passing it into a distillation tower, selecting the fraction at 230℃ to 380℃ as the crude product of the drilling fluid base fluid; (2) passing the crude product obtained in step (1) into a hydrocracking reactor for hydrocracking treatment to obtain a semi-finished product; (3) passing the semi-finished product obtained in step (2) into an isomerization dewaxing reactor for isomerization dewaxing treatment, wherein the reaction zone of the isomerization dewaxing reactor is filled with an isomerization dewaxing catalyst; (4) passing the dewaxed product of step (3) into a hydrotreating reactor for hydrotreating treatment to obtain a refined product, wherein the reaction zone of the hydrotreating reactor is filled with a hydrotreating catalyst; (5) passing the product after purification in step (4) through a composite molecular sieve for treatment; (6) passing the refined product obtained in step (5) into a preheating furnace for preheating, and passing the preheated refined product into a molecular distiller in sequence for molecular distillation treatment to obtain a heavy fraction and a light fraction, and selecting the heavy fraction as a drilling fluid base fluid product; The composite molecular sieve is a SAPO-11 / ZSM-22 composite molecular sieve, and the mass ratio of SAPO-11 to ZSM-22 is 3:1; The isomerization dewaxing catalyst is a supported single-atom noble metal catalyst, which contains a second carrier and a single-atom noble metal supported on the second carrier; The second carrier is a molecular sieve or an alumina carrier; The single-atom noble metal is selected from one or more of platinum, palladium, ruthenium, rhodium, iridium, gold or silver; The weight content of the monatomic noble metal in the isomerization dewaxing catalyst is 0.1 to 1.0%; The hydrotreating catalyst is a supported single-atom noble metal carrier, which contains a third carrier and a single-atom noble metal supported on the third carrier; The third carrier is an alumina carrier; The single-atom noble metal is selected from one or more of platinum, palladium, ruthenium, rhodium, iridium, gold or silver.

2. The method for preparing a drilling fluid base fluid according to claim 1, characterized in that: In the step (6), the operating pressure of the molecular distiller is 10-100 Pa, and the reaction temperature is 50-80° C.

3. The method for preparing a drilling fluid base fluid according to claim 1, characterized in that: In step (2), the reaction zone of the hydrocracking reactor is filled with a first hydrocracking catalyst and a second hydrocracking catalyst having different cracking activities, the operating pressure in the hydrocracking reactor is 14-16 MPa, and the reaction temperature is 380-400° C.; The first hydrocracking catalyst and the second hydrocracking catalyst are both supported non-precious metal catalysts, and the supported non-precious metal catalysts contain a first carrier and a support, wherein the first carrier supports at least one Group VIII metal element and at least one Group VIB metal element.

4. The method for preparing a drilling fluid base fluid according to claim 3, characterized in that: The content of the Group VIII metal element is 1-10wt% of the total amount of the first hydrocracking catalyst, and the content of the Group VIB metal element is 5-50wt% of the total amount of the first hydrocracking catalyst; the content of the Group VIII metal element is 1-10wt% of the total amount of the second hydrocracking catalyst, and the content of the Group VIB metal element is 5-50wt% of the total amount of the second hydrocracking catalyst.

5. The method for preparing a drilling fluid base fluid according to claim 3, characterized in that: The VIB group metal element is molybdenum and / or tungsten; the VIII group metal element is cobalt and / or nickel; the first carrier is selected from one or more of γ-alumina, silicon oxide, aluminum oxide-silicon oxide, titanium oxide, and magnesium oxide.

6. The method for preparing a drilling fluid base fluid according to claim 3, characterized in that: The cracking activity of the first hydrocracking catalyst is greater than that of the second hydrocracking catalyst, and the packing volume ratio of the first hydrocracking catalyst to the second hydrocracking catalyst is 1:5 to 5:

1.

7. The method for preparing a drilling fluid base fluid according to claim 1, characterized in that: The second carrier is ZSM-12 molecular sieve or ZSM-11 molecular sieve or ZSM-12 / ZSM-11 composite molecular sieve.

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