Drilling fluid, latex anti-collapse inhibitor and preparation method and application thereof
By preparing a latex-based anti-collapse inhibitor, the problem of wellbore instability in drilling fluid was solved, achieving low-cost and high-efficiency wellbore stabilization, with plugging performance comparable to MAX-SHIELD™, thus reducing production costs.
Patent Information
- Application Number
- CN202411144904.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2026-03-03
AI Technical Summary
Existing drilling fluid anti-collapse inhibitors are either too expensive or their performance does not meet the requirements, especially their insufficient temperature resistance and plugging performance, resulting in high production costs.
A method for preparing latex-based anti-collapse inhibitors was adopted, in which a first monomer, a second monomer, and a third monomer were mixed and heated in a reactor to prepare a nano-latex-based anti-collapse inhibitor, which can be used in drilling fluids to seal micro-fractures, reduce filtration loss, and enhance lubrication.
It achieves effective plugging at the initial microfracture formation, maintains wellbore stability, reduces drilling fluid loss, enhances lubrication, has a lower cost, and outperforms existing products, especially in temperature resistance and plugging ability, which are comparable to MAX-SHIELD™.
Smart Images
Figure CN121591962A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oilfield drilling fluid technology, and in particular to a drilling fluid, a latex-based anti-collapse inhibitor, its preparation method, and its application. Background Technology
[0002] Wellbore instability is a common problem in drilling operations, posing safety hazards and causing significant losses to life and property. Currently, the main solutions to wellbore instability issues involve using anti-collapse inhibitors to suppress shale hydration and drilling fluid systems. Traditional anti-collapse inhibitors include inorganic salts, polymers, and bitumen-based agents, but these suffer from poor temperature resistance and significant shale expansion.
[0003] A representative product in the research of nano-anti-collapse agents is Baker Hughes' deformable nano-plugging polymer "MAX-SHIELD™". This product is widely used in high-temperature drilling fluid systems due to its excellent temperature resistance, anti-collapse properties, and physical plugging performance. Although MAX-SHIELD™ has good performance, its high cost results in a product price that is about 3 to 4 times that of other similar products. The high price directly increases production costs and reduces profit margins.
[0004] The environmentally friendly nano-deformable polymer plugging agent PF-Green Seal developed by Tianjin CNOOC Chemical Co., Ltd., and the nano-polyester NP-1 for drilling fluid anti-collapse plugging agent developed by Shandong Deshunyuan Petroleum Technology Co., Ltd., have achieved initial industrialization and some results in the field. However, their overall performance still lags behind that of "MAX-SHIELD™".
[0005] Therefore, existing technologies still need improvement.
[0006] Invention To address the aforementioned technical problems, this invention provides a drilling fluid, a latex-based anti-collapse inhibitor, its preparation method, and its application, thereby resolving the technical issues of existing anti-collapse inhibitors having high costs or failing to meet performance requirements.
[0007] To address the aforementioned technical problems, in one aspect, some embodiments of the present invention disclose a method for preparing a latex-based anti-collapse inhibitor for drilling fluids, comprising: Step 1: Mix the first monomer and the third monomer evenly in the reactor; Step 2: Add the second monomer and dispersant to the reactor and stir until homogeneous; Step 3 involves heating the reactor to carry out the reaction, thereby obtaining the reaction products; Step four involves cooling and pulverizing the reaction product to obtain a nano-latex-based anti-collapse inhibitor for drilling fluid.
[0008] In some embodiments, the first monomer is one or a mixture of two or more of ethyl acetate, butyl acetate, or octyl acrylate.
[0009] In some embodiments, the second monomer is vinyltrimethoxysilane.
[0010] In some embodiments, the third monomer is one or a mixture of two or more of alkyd resin, polyurethane resin, or epoxy resin.
[0011] In some embodiments, in step three, the heating temperature is 30-50°C and the heating time is 2-3 hours.
[0012] In some embodiments, the dispersant is one or a mixture of two or more of the following: emulsifying dispersant, inert powder dispersant, and nano-dispersant.
[0013] In some embodiments, the addition ratio of the first monomer, the second monomer and the third monomer by mass is (15-40):(1-3):(15-40):(2-7).
[0014] In some embodiments, the first monomer is ethyl acetate, the second monomer is vinyltrimethoxysilane, the third monomer is alkyd resin, and the dispersant is an emulsifier-type dispersant; Alternatively, the first monomer is butyl acetate, the second monomer is vinyltrimethoxysilane, and the third monomer is polyurethane resin; Alternatively, the first monomer is octyl acrylate, the second monomer is vinyltrimethoxysilane, and the third monomer is epoxy resin.
[0015] In some embodiments, by mass ratio, Ethyl acetate: vinyltrimethoxysilane: alkyd resin: emulsifier-type dispersant = (14-16): 1: (14-16): (1.8-2.2); Alternatively, butyl acetate: vinyltrimethoxysilane: polyurethane resin: inert powder dispersant = (23-27): (1.5-2.5): (23-27): (4.5-5.5); Alternatively, octyl acrylate: vinyltrimethoxysilane: epoxy resin: nano-dispersant = (33-37): 3: (33-37): (6.5-7.5). On the other hand, some embodiments of the present invention also disclose a latex-based anti-collapse inhibitor for drilling fluid, which is prepared by the aforementioned method for preparing a nano-latex-based anti-collapse inhibitor for drilling fluid.
[0016] In some embodiments, when the mass fraction is 2%, the medium pressure filtration loss is 8-12 mL over 30 minutes.
[0017] Thirdly, embodiments of the present invention also disclose a drilling fluid comprising the aforementioned latex-based anti-collapse inhibitor for drilling fluids.
[0018] Fourthly, embodiments of the present invention also disclose the application of the aforementioned latex-based anti-collapse inhibitor for drilling fluids in suppressing shale expansion.
[0019] By adopting the above technical solution, the present invention has at least the following beneficial effects: This invention provides a drilling fluid, a latex-based anti-collapse inhibitor, its preparation method, and its application. It effectively seals microfractures at the initial stage of formation, preventing pressure transmission and subsequent microfracture expansion to maintain wellbore stability. It significantly reduces filtration loss in the drilling fluid system, enhances the lubrication capacity of the drilling fluid, and improves the system's ability to inhibit shale expansion, effectively solving the severe collapse problem in shale formations. It is a highly stable, well-dispersible, and low-agglomeration nanoscale anti-collapse inhibitor with a simple preparation process and low cost, showing promising application prospects. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a flowchart illustrating a method for preparing a latex-based anti-collapse inhibitor for drilling fluid, as disclosed in some embodiments of the present invention. Detailed Implementation
[0022] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
[0023] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values set forth in these embodiments should be interpreted as exemplary only and not as limiting.
[0024] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0025] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.
[0026] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.
[0027] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.
[0028] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.
[0029] The purpose of this invention is to provide a latex-based anti-collapse inhibitor for drilling fluids, whose temperature resistance and plugging ability are comparable to "MAX-SHIELD™", and which is superior to similar products in terms of lubrication and reduction of plugging fluid loss. The product price is more than 50% lower than that of the deformable nano-plugging polymer "MAX-SHIELD™" developed by Baker Hughes. Figure 1As shown, its preparation method includes: After thoroughly mixing the first and third monomers in the reactor, add the second monomer and dispersant and continue stirring until homogeneous. Heat the reactor to 30℃-50℃ and react for 2-3 hours. Then pour out the mixture, let it cool, and pulverize it. In the above preparation method, the first monomer is one or a mixture of ethyl acetate, butyl acetate, or octyl acrylate. The second monomer is vinyltrimethoxysilane. The third monomer is one or a mixture of alkyd resin, polyurethane resin, or epoxy resin. The mass ratio of the first monomer, the second monomer, and the third monomer is (15-40):(1-3):(15-40):(2-7). The dispersant is one or a mixture of emulsifying dispersant, inert powder dispersant, and nano-dispersant.
[0030] The nano-latex-based anti-collapse inhibitor for drilling fluids prepared using the above method, at a mass fraction of 2%, exhibits a medium-pressure filtration loss of 8-12 mL over 30 minutes. This anti-collapse inhibitor can be used in drilling fluids to inhibit shale swelling.
[0031] Example 1 At room temperature, 15 parts of ethyl acetate and 15 parts of alkyd resin were placed in a reaction vessel and stirred evenly. Then, 1 part of vinyltrimethoxysilane and 2 parts of emulsifier-type dispersant nano silica were added and stirred evenly. The reaction vessel was heated to 30°C and reacted for 2 hours. After that, the mixture was poured out, cooled, and pulverized to obtain the anti-collapse inhibitor.
[0032] Example 2 At room temperature, 25 parts of butyl acetate and 25 parts of polyurethane resin were placed in a reaction vessel and stirred evenly. Then, 2 parts of vinyltrimethoxysilane and 5 parts of inert powder dispersant nano silica were added and stirred evenly. The reaction vessel was heated to 40°C and reacted for 2.5 hours. After being poured out, cooled and pulverized, the anti-collapse inhibitor was obtained.
[0033] Example 3 At room temperature, 35 parts of octyl acrylate and 35 parts of epoxy resin were placed in a reaction vessel and stirred evenly. Then, 3 parts of vinyltrimethoxysilane and 7 parts of nano-dispersant micro-nano calcium carbonate were added and stirred evenly. The reaction vessel was heated to 50°C and reacted for 3 hours. After that, the mixture was poured out, cooled, and pulverized to obtain the anti-collapse inhibitor.
[0034] Example 4 At room temperature, 35 parts of octyl acrylate and 35 parts of epoxy resin were placed in a reaction vessel and stirred evenly. Then, 3 parts of vinyltrimethoxysilane and 7 parts of nano-dispersant were added and stirred evenly. The reaction vessel was heated to 20°C and reacted for 3 hours. After cooling, the mixture was pulverized to obtain the anti-collapse inhibitor.
[0035] Example 5 At room temperature, 35 parts of octyl acrylate and 35 parts of epoxy resin were placed in a reaction vessel and stirred evenly. Then, 3 parts of vinyltrimethoxysilane and 7 parts of nano-dispersant were added and stirred evenly. The reaction vessel was heated to 30°C and reacted for 3 hours. After that, the mixture was poured out, cooled, and pulverized to obtain the anti-collapse inhibitor.
[0036] Example 6 At room temperature, 35 parts of octyl acrylate and 35 parts of epoxy resin were placed in a reaction vessel and stirred evenly. Then, 3 parts of vinyltrimethoxysilane and 7 parts of nano-dispersant were added and stirred evenly. The reaction vessel was heated to 40°C and reacted for 3 hours. After that, the mixture was poured out, cooled, and pulverized to obtain the anti-collapse inhibitor.
[0037] Example 7 At room temperature, 35 parts of octyl acrylate and 35 parts of epoxy resin were placed in a reaction vessel and stirred evenly. Then, 3 parts of vinyltrimethoxysilane and 7 parts of nano-dispersant were added and stirred evenly. The reaction vessel was heated to 60°C and reacted for 3 hours. After cooling, the mixture was pulverized to obtain the anti-collapse inhibitor.
[0038] Comparing the effects of temperature on the reaction in Examples 3-7, the results showed that when the heating temperature was 20°C, the product remained unsolidified for 24 hours; when the heating temperature was 30°C, the product began to solidify after 5 hours; when the heating temperature was 40°C, the product began to solidify after 60 minutes; when the heating temperature was 50°C, the product began to solidify after 30 minutes; and when the heating temperature was 60°C, product 3 solidified rapidly. Through testing the reaction products at temperatures between 20-60°C, the laboratory study determined that a reaction temperature of 30-50°C was more suitable for the time from the start of the reaction to the solidification of the product.
[0039] Example 8 (Evaluation of Filtration Loss) The anti-collapse inhibitor used in this example was the product prepared in Example 1. The product's ability to reduce filtration loss was tested using the API filtration loss test method. The test method was as follows: 1000 ml of bentonite-based slurry with a mass fraction of 4% was prepared. 400 ml of the slurry was taken and 2% sulfonated bitumen was added while stirring. Another 400 ml of the slurry was taken and 2% of the product was added while stirring. The medium-pressure filtration loss of the slurries with added sulfonated bitumen and product was tested using a six-unit medium-pressure filtration loss meter, and the filtration loss values were read over 30 minutes. Table 1 shows the results of the filtration loss determination.
[0040] Table 1
[0041] Example 9 (Suppression of Shale Swelling) The anti-collapse inhibitor used in this example is the product prepared in Example 1. The NP-1 shale expander was used to test the product's ability to inhibit shale expansion. The test method was as follows: 1000 ml of a 4% bentonite-based slurry was prepared. 400 ml of the slurry was then mixed with 2% sulfonated bitumen. Another 400 ml of the slurry was mixed with the product (2% by mass) in the same mixture. Two 10 g portions of dry bentonite were weighed and compacted at 4 MPa for 5 min. 10 ml of the filtrate from each slurry was measured, and the linear expansion was tested over 8 hours. The results were compared with the slurry test data, and the results are shown in Table 2.
[0042] Table 2
[0043] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.
[0044] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.
Claims
1. A method for preparing a latex-based anti-collapse inhibitor for drilling fluids, characterized in that, include: Step 1: Mix the first monomer and the third monomer evenly in the reactor; Step 2: Add the second monomer and dispersant to the reactor and stir until homogeneous; Step 3 involves heating the reactor to carry out the reaction, thereby obtaining the reaction products; Step four involves cooling and pulverizing the reaction product to obtain a nano-latex-based anti-collapse inhibitor for drilling fluid.
2. The preparation method of the latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The first monomer is one or a mixture of two or more of ethyl acetate, butyl acetate, or octyl acrylate.
3. The preparation method of the nano-latex anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The second monomer is vinyltrimethoxysilane.
4. The preparation method of the latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The third monomer is one or a mixture of two or more of alkyd resin, polyurethane resin, or epoxy resin.
5. The method for preparing a latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, In step three, the heating temperature is 30-50℃; the heating time is 2-3 hours.
6. The method for preparing a latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The dispersant is one or a mixture of two or more of the following: emulsifying dispersant, inert powder dispersant, and nano dispersant.
7. The preparation method of the latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The proportions of the first monomer, the second monomer and the third monomer by mass are (15-40): (1-3): (15-40): (2-7).
8. The method for preparing a latex-based anti-collapse inhibitor for drilling fluid according to claim 1, characterized in that, The first monomer is ethyl acetate, the second monomer is vinyltrimethoxysilane, the third monomer is alkyd resin, and the dispersant is an emulsifying dispersant; Alternatively, the first monomer is butyl acetate, the second monomer is vinyltrimethoxysilane, and the third monomer is polyurethane resin; Alternatively, the first monomer is octyl acrylate, the second monomer is vinyltrimethoxysilane, and the third monomer is epoxy resin.
9. The preparation method of the nano-latex anti-collapse inhibitor for drilling fluid according to claim 8, characterized in that, In terms of mass ratio, Ethyl acetate: vinyltrimethoxysilane: alkyd resin: emulsifier-type dispersant = (14-16): 1: (14-16): (1.8-2.2); Alternatively, butyl acetate: vinyltrimethoxysilane: polyurethane resin: inert powder dispersant = (23-27): (1.5-2.5): (23-27): (4.5-5.5); Alternatively, octyl acrylate: vinyltrimethoxysilane: epoxy resin: nano-dispersant = (33-37): 3: (33-37): (6.5-7.5).
10. A nano-emulsion-based anti-collapse inhibitor for drilling fluids, characterized in that, It is prepared by the method of any one of claims 1-9 for preparing nano-latex anti-collapse inhibitors for drilling fluid.
11. The nano-emulsion anti-collapse inhibitor for drilling fluid according to claim 10, characterized in that, When the mass fraction is 2%, the filtration loss under medium pressure is 8-12 mL over 30 minutes.
12. A drilling fluid, characterized in that, Including the latex-based anti-collapse inhibitor for drilling fluids as described in claim 10 or 11.
13. The application of the latex-based anti-collapse inhibitor for drilling fluids as described in claim 10 or 11 in the prevention of shale swelling.