High temperature resistant fluid loss additive, preparation method and application thereof
By preparing a high-molecular polymer filtration loss reducer using maleic anhydride, isobutylene, and long-chain α-olefins as raw materials, the problem of large filtration loss under high temperature conditions was solved, achieving low filtration loss and excellent rheological properties in drilling fluids under high temperature and high pressure, which is suitable for gas-to-oil synthetic-based drilling fluid systems.
Patent Information
- Application Number
- CN202310778142.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-29
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2043-06-29
AI Technical Summary
Existing gas-to-oil synthetic drilling fluid filtration reducers suffer from high filtration loss and poor rheological properties under high temperature conditions, as well as environmental pollution and high cost, which limits their application under high temperature and high pressure conditions.
Using raw materials such as maleic anhydride, isobutylene, long-chain α-olefins and thermally decomposable initiators, a high-temperature filtration loss reducing agent is prepared through heating reaction and solvent precipitation process, forming a polymer with excellent high-temperature and high-pressure filtration loss reducing effect.
It exhibits low filtration loss and excellent rheological properties under high temperature and high pressure, solving the problems of high filtration loss and poor rheological properties in gas-to-oil synthetic drilling fluid systems. It is suitable for drilling fluid applications under high temperature and high pressure conditions.
Smart Images
Figure CN119219843B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to an anti-high-temperature fluid loss additive, a preparation method and application thereof. BACKGROUND
[0002] In recent years, with the improvement of drilling technology, oil and gas resource exploration and development are continuously developing to deep strata. Drilling fluid plays a crucial role in the whole drilling process. Among them, gas oil synthetic base drilling fluid has the advantages of high temperature resistance, salt and calcium invasion resistance, good lubricity, and small damage to oil and gas layers, and has gradually become the first choice for drilling complex strata wells such as deep and ultra-deep wells, high-inclination directional wells, multi-lateral wells and horizontal wells. As a key component of gas oil synthetic base drilling fluid system, the main function of the fluid loss additive is to form a thin and dense mud cake on the well wall, reduce the filtration loss, maintain the stability of the wellbore, and reduce the invasion of liquid and solid phases of the drilling fluid into the strata and damage to the oil and gas layers, which is one of the indispensable treatment agents in the drilling fluid.
[0003] At present, the existing gas oil synthetic base drilling fluid fluid loss additives mainly include asphalt, humic acid amine, other natural high molecular modified and high molecular polymer. Among them, asphalt fluid loss additive has the advantages of wide material selection and low price, and has been widely used in the past. However, asphalt fluid loss additive has the disadvantages of reducing drilling speed, polluting the environment and increasing the amount, and has been limited in use in the formulation of gas oil synthetic base drilling fluid in environmentally sensitive areas in China and most areas abroad. Humic acid amine fluid loss additive has the characteristics of environmental friendliness, improved drilling fluid rheological property and improved emulsion stability, but it is easy to decompose under high temperature conditions and loses its function. For example, the performance of the humic acid fluid loss additive prepared in the article "Development and Performance of New Anti-high-temperature Oil-based Drilling Fluid Fluid Loss Additive" (Drilling Fluid and Completion Fluid, 2016, 33(01)) was determined in the anti-high-temperature high-density oil-based drilling fluid. The results show that the high temperature and high pressure filtration loss of the fluid loss additive is 4.0ml at 180℃, and the high temperature and high pressure filtration loss is 8.6ml at 220℃, and the anti-high-temperature ability needs to be improved.
[0004] The polymer polymer type fluid loss additive has the characteristics of environmental friendliness, low fluid loss under high temperature and high pressure, and long service life under high temperature. The main chain of the polymer fluid loss additive is carbon-carbon structure, so it has good temperature resistance. The fluid loss additive can be designed and functionalized by branched chain to have the dual effects of fluid loss and leak stoppage while drilling. It is found in the experimental research of the article "Research on the Influence of PIBSI on the Performance of Oil-based Drilling Fluid" (Journal of Petroleum and Chemical Higher School, 2014, 27(04)) that under high temperature conditions, different mass fractions of PIBSI are added to different oil-based drilling fluid systems, the rheological properties of each system under the condition of 65℃ are studied, and the effect of PIBSI on the performance of two kinds of oil-based drilling fluid systems under high temperature conditions is studied, especially under the condition of 150℃. The effect of the fluid loss additive on high temperature and high pressure fluid loss is general. In addition, the existing polymer polymer type gas oil synthetic base fluid loss additive mainly depends on import and is expensive, which seriously limits its large-scale application.
[0005] Therefore, it is urgent to develop a new structure of polymer type fluid loss additive which still has good fluid loss performance under high temperature conditions. SUMMARY
[0006] In order to at least partially solve the above technical problems, the present application provides a fluid loss additive with good temperature resistance, low fluid loss under high temperature and high pressure, and good fluid loss effect, as well as a preparation method and application thereof.
[0007] As one aspect of the present application, it relates to a high temperature resistant fluid loss additive, which comprises the following raw materials in parts by weight: maleic anhydride 10 parts, isobutene 0-5 parts, long chain alpha-olefin 0.8-27 parts, and initiator 0.1-3.7 parts.
[0008] In specific embodiments, the fluid loss additive further comprises a solvent 30-60 parts.
[0009] In specific embodiments, the solvent is selected from organic acid alkyl ester and / or aromatic hydrocarbon.
[0010] In specific embodiments, the long chain alpha-olefin is selected from alpha-olefin with carbon atom number of 6-19.
[0011] In specific embodiments, the initiator is a thermal decomposition type initiator.
[0012] In specific embodiments, the thermal decomposition type initiator is selected from one or more of dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, diperazelaoyl peroxide, t-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile, azobisisovaleronitrile and azobisisoheptonitrile.
[0013] As another aspect of the present application, a method for preparing the anti-high-temperature fluid loss additive described above is provided, and the method comprises the following steps:
[0014] S1, sequentially adding maleic anhydride, initiator, long-chain alpha-olefin and solvent, stirring and dissolving, adding isobutene, and heating and reacting;
[0015] S2, after the reaction solution of S1 is cooled to room temperature, pouring into n-hexane, and after the reaction solution of S1 is cooled to room temperature, pouring into n-hexane, and precipitating solid;
[0016] S3, filtering and washing the solid precipitated in S2, drying and crushing the washed solid to obtain the fluid loss additive.
[0017] In specific embodiments, in S1, the inert gas is selected from one or more of nitrogen, helium and argon.
[0018] In specific embodiments, in S1, the reaction temperature is 50-80℃, and the reaction time is 3-6h.
[0019] As still another aspect of the present application, the anti-high-temperature fluid loss additive described above is applied to a gas-to-liquid synthetic-based drilling fluid.
[0020] As still another aspect of the present application, a gas-to-liquid synthetic-based drilling fluid is provided, and the gas-to-liquid synthetic-based drilling fluid contains the anti-high-temperature fluid loss additive described above.
[0021] As still another aspect of the present application, an oilfield drilling process is provided, and the drilling process uses the gas-to-liquid synthetic-based drilling fluid described above.
[0022] The anti-high-temperature fluid loss additive provided by the present application is suitable for a gas-to-liquid synthetic-based drilling fluid system, and has not only good high-temperature and high-pressure fluid loss reduction effect, but also good temperature resistance and low fluid loss. The fluid loss additive solves the problems of large fluid loss, poor rheological property, easy settling of barite and environmental pollution of the gas-to-liquid synthetic-based drilling fluid system under high-temperature and high-pressure conditions.
[0023] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structure particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 The infrared spectrum of the fluid loss additive prepared in Example 3 of the present application. DETAILED DESCRIPTION
[0025] The application will be further described in connection with the specific embodiments. The scope of the application is not limited by the following examples. The materials used in the following examples are listed in Table 1. Other materials not listed are commercially available.
[0026] Table 1: Material source
[0027]
[0028]
[0029] The inventors have further studied the polymer-based fluid loss additive and its preparation method, and provide Examples 1-4.
[0030] Example 1
[0031] The fluid loss additive of this example includes the following raw materials in parts by weight: maleic anhydride 10 parts, initiator (azobisisobutyronitrile) 0.1 part, long-chain α-olefin (1-hexene) 0.8 part, solvent (butyl acetate) 30 parts, isobutene 5 parts.
[0032] The fluid loss additive of this example is prepared by the following steps:
[0033] Maleic anhydride 10 parts, azobisisobutyronitrile 0.1 part, 1-hexene 0.8 part, butyl acetate 30 parts are sequentially added to a stainless steel reaction kettle, stirred and dissolved, replaced with nitrogen for 3 times, then isobutene 5 parts is added, heated to 60°C, and reacted for 5 hours.
[0034] After the reaction solution is cooled to room temperature, it is slowly poured into n-hexane, and the solid is precipitated. The product is filtered and washed, and the washed product is dried and crushed at 75°C to obtain the fluid loss additive.
[0035] Example 2
[0036] The fluid loss additive of this example includes the following raw materials in parts by weight: maleic anhydride 10 parts, initiator (azobisisobutyronitrile 0.2 part, azobisisobutyronitrile 0.2 part) 0.4 part, long-chain α-olefin (1-hexadecene) 4.5 parts, solvent (isopentyl acetate) 40 parts, isobutene 4.5 parts.
[0037] The fluid loss additive of this example is prepared by the following steps:
[0038] Maleic anhydride 10 parts, azobisisobutyronitrile 0.2 part, azobisisobutyronitrile 0.2 part, 1-hexadecene 4.5 parts, isopentyl acetate 40 parts are sequentially added to a stainless steel reaction kettle, stirred and dissolved, replaced with nitrogen for 3 times, then isobutene 4.5 parts is added, heated to 50°C, and reacted for 6 hours.
[0039] After the reaction solution is cooled to room temperature, it is slowly poured into n-hexane, and the solid is precipitated. The product is filtered and washed, and the washed product is dried and crushed to obtain the fluid loss additive.
[0040] Example 3
[0041] The fluid loss additive of this example comprises the following raw material components by weight: maleic anhydride 10 parts, initiator (azobisisobutyronitrile) 0.2 parts, long-chain α-olefin (1-hexadecene) 18 parts, solvent (butyl acetate) 50 parts, isobutene 1 part.
[0042] The fluid loss additive of this example is prepared by the following steps:
[0043] Maleic anhydride 10 parts, azobisisobutyronitrile 0.2 parts, 1-hexadecene 18 parts, and butyl acetate 50 parts are sequentially added to a stainless steel reaction kettle and stirred and dissolved. After argon replacement for 3 times, isobutene 1 part is added, heated and warmed to 70°C, and reacted for 4 hours.
[0044] After the reaction solution is cooled to room temperature, it is slowly poured into n-hexane, and the solid is precipitated. The product is filtered and washed, and the washed product is dried and crushed to obtain the fluid loss additive.
[0045] The infrared spectrum of the fluid loss additive prepared in this example is shown in Figure 1 .
[0046] Example 4
[0047] The fluid loss additive of this example comprises the following raw material components by weight: maleic anhydride 10 parts, initiator (dibenzoyl peroxide) 3.7 parts, long-chain α-olefin (1-nonadecene) 27 parts, solvent (ethyl acetate 15 parts, toluene 45 parts) 60 parts, isobutene 0 parts.
[0048] Maleic anhydride 10 parts, dibenzoyl peroxide 3.7 parts, 1-nonadecene 27 parts, ethyl acetate 15 parts, and toluene 45 parts are sequentially added to a stainless steel reaction kettle and stirred and dissolved. After nitrogen replacement for 3 times, heated and warmed to 80°C, and reacted for 3 hours.
[0049] After the reaction solution is cooled to room temperature, it is slowly poured into n-hexane, and the solid is precipitated. The product is filtered and washed, and the washed product is dried and crushed to obtain the fluid loss additive.
[0050] According to the composition of raw materials and the preparation method of the fluid loss additive of the present application, by adjusting the amount of part of the raw materials, the following comparative examples 1-2 are obtained.
[0051] Comparative Example 1
[0052] The filter loss reducer of the present comparative example comprises the following raw material components by weight: maleic anhydride 10 parts, initiator (azobisisobutyronitrile) 0.2 parts, long-chain α-olefin (1-hexadecene) 2 parts, solvent (butyl acetate) 50 parts, isobutene 7 parts.
[0053] Maleic anhydride 10 parts, azobisisobutyronitrile 0.2 parts, 1-hexadecene 2 parts, and butyl acetate 50 parts were sequentially added to a stainless steel reaction kettle for stirring and dissolution, argon was replaced for 3 times, isobutene 7 parts was added, heated to 70℃, and reacted for 4 hours.
[0054] After the reaction solution was cooled to room temperature, it was slowly poured into n-hexane, and the solid was precipitated, the product was filtered and washed, and the washed product was dried and crushed to obtain the filter loss reducer.
[0055] Comparative Example 2
[0056] The filter loss reducer of the present comparative example comprises the following raw material components by weight: maleic anhydride 10 parts, initiator (azobisisobutyronitrile) 0.2 parts, long-chain α-olefin (1-hexadecene) 2 parts, solvent (butyl acetate) 50 parts, isobutene 7 parts.
[0057] Maleic anhydride 10 parts, azobisisobutyronitrile 0.2 parts, 1-hexadecene 2 parts, and butyl acetate 50 parts were sequentially added to a stainless steel reaction kettle for stirring and dissolution, argon was replaced for 3 times, isobutene 7 parts was added, heated to 70℃, and reacted for 4 hours.
[0058] After the reaction solution was cooled to room temperature, it was slowly poured into n-hexane, and the solid was precipitated, the product was filtered and washed, and the washed product was dried and crushed to obtain the filter loss reducer.
[0059] The filter loss reducers prepared in Examples 1-4 and Comparative Examples 1-2 were applied to oil-based drilling technology to prepare drilling fluid. According to the conventional drilling fluid preparation method in the industry, Application Examples 1-4 and Comparative Examples 1-2 were given.
[0060] Application Example 1
[0061] The drilling fluid of the present application example comprises the following components by weight: 80 parts of gas oil
[0062] (185V) + 20 parts of CaCl2 aqueous solution (mass concentration of 20%) + 3 parts of main emulsifier (DR-EM) + 2 parts of auxiliary emulsifier (DR-CO) + 2 parts of organic clay (HF-120) + 4 parts of filter loss reducer (Example 1) + 2 parts of calcium oxide + 300 parts of barite.
[0063] Application Example 2
[0064] The difference from Application Example 1 is that the filter loss reducer prepared in Example 2 is used instead of the filter loss reducer in Application Example 1.
[0065] Application Example 3
[0066] The difference from Application Example 1 is that the filtration loss reducing agent prepared in Example 3 is used instead of the filtration loss reducing agent in Application Example 1.
[0067] Application Example 4
[0068] The difference from Application Example 1 is that the filtration loss reducing agent prepared in Example 4 is used instead of the filtration loss reducing agent in Application Example 1.
[0069] Application Comparative Example 1
[0070] The difference from Application Example 1 is that the filtration loss reducing agent prepared in Comparative Example 1 is used instead of the filtration loss reducing agent in Application Example 1.
[0071] Application Comparative Example 2
[0072] The difference from Application Example 1 is that the filtration loss reducing agent prepared in Comparative Example 2 is used instead of the filtration loss reducing agent in Application Example 1.
[0073] In addition, other types of filtration loss reducing agents used in actual applications are used as comparative examples of the present invention. Comparative examples 3 and 4 are given.
[0074] Application Comparative Example 3
[0075] The drilling fluid used in this comparative application, by weight, comprises the following components: 80 parts gas-to-oil (185V) + 20 parts CaCl2 aqueous solution (mass concentration of 20%) + 3 parts primary emulsifier (DR-EM) + 2 parts secondary emulsifier (DR-CO) + 2 parts organo-earth (HF-120) + 4 parts filtration loss reducer - bitumen + 2 parts calcium oxide + 300 parts barite.
[0076] Application Comparative Example 4
[0077] The drilling fluid used in this comparative application, by weight, comprises the following components: 80 parts gas-to-oil (185V) + 20 parts CaCl2 aqueous solution (mass concentration of 20%) + 3 parts primary emulsifier (DR-EM) + 2 parts secondary emulsifier (DR-CO) + 2 parts organo-earth (HF-120) + 4 parts filtration loss reducer - humic acid amines + 2 parts calcium oxide + 300 parts barite.
[0078] The above application examples 1-4 and application comparison examples 1-4 were subjected to the following performance tests. The test results were recorded in Table 2 below, following the relevant methods described in the national standard GB / T16783.2 "Field Testing of Drilling Fluids for the Petroleum and Natural Gas Industry".
[0079] Table 2: Drilling Fluid Performance Evaluation Results
[0080]
[0081] Based on the above experiments and the results in Table 2, it can be seen that Comparative Examples 3 and 4 are gas-to-oil synthetic drilling fluid systems formulated with asphalt-based and humic acid amine-based filtration reducers, respectively. After aging at 220℃, the synthetic drilling fluid system in Comparative Example 3 exhibited a high-temperature, high-pressure filtration loss of 12.4 ml. Excessive filtration loss can easily lead to wellbore instability and collapse; therefore, asphalt-based filtration reducers cannot be used as filtration reducers for gas-to-oil synthetic drilling fluid systems resistant to 220℃. After aging at 220℃, the synthetic drilling fluid system in Comparative Example 4 exhibited a high-temperature, high-pressure filtration loss of 8.2 ml, which is better than that of the asphalt-based filtration reducer. Furthermore, its demulsification voltage of 1012V was superior to that of the asphalt-based filtration reducer drilling fluid system (617V), indicating that the humic acid amine-based filtration reducer outperforms the asphalt-based filtration reducer product under 220℃ high-temperature conditions. However, a high-temperature and high-pressure filtration loss of 8.2 ml is also too large and can easily cause wellbore instability. Therefore, it cannot be directly used as a filtration loss reducer in a 220℃ high-temperature gas-to-oil synthetic drilling fluid system.
[0082] The polymer filtration reducer prepared in Examples 1-4 of this invention, when used in gas-to-oil synthetic drilling fluid systems, exhibits a filtration loss of 2.4–2.8 ml under high-temperature and high-pressure aging at 220°C. This demonstrates that the polymer filtration reducer of this patent possesses excellent high-temperature and high-pressure filtration performance, meeting the technical requirements for high-temperature and high-pressure filtration performance in 220°C gas-to-oil synthetic drilling fluid systems. The demulsification voltage of the gas-to-oil synthetic drilling fluid systems in Examples 1-4 of this invention is above 1154V, significantly higher than the 400V or higher required at drilling sites, indicating that the polymer filtration reducer of this patent is beneficial to the electrical stability of synthetic drilling fluid systems. The polymer filtration reducer of this patent effectively solves the problem of high high-temperature and high-pressure filtration loss in 220°C gas-to-oil synthetic drilling fluid systems.
[0083] The high-temperature and high-pressure filtration loss of the gas-to-oil synthetic drilling fluids prepared by the polymer filtration loss reducers prepared in Comparative Examples 1 and 2 was 4.6 ml and 5.3 ml, respectively. The filtration loss performance was significantly better than that of the gas-to-oil synthetic drilling fluids prepared by asphalt-based filtration loss reducers and humic acid amine-based filtration loss reducers, but lower than that of the polymer filtration loss reducers prepared in Examples 1 to 4.
[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All modifications or applications made in accordance with the above embodiments are within the scope of protection of this technical solution.
[0085] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of this invention. The full scope of this invention is given by the appended claims and any equivalents thereof.
Claims
1. A high-temperature resistant filtration loss reducer, characterized in that, It is prepared from the following raw materials in parts by weight: 10 parts maleic anhydride, 1-5 parts isobutylene, 0.8-27 parts long-chain α-olefin, 0.1-3.7 parts initiator, and 30-60 parts solvent. The long-chain α-olefins are selected from α-olefins with 6 to 19 carbon atoms.
2. The high-temperature filtration loss reducing agent according to claim 1, characterized in that, The solvent is selected from organic acid alkyl esters and / or aromatic hydrocarbons.
3. The high-temperature filtration loss reducing agent according to claim 1, characterized in that, The initiator is a thermally decomposable initiator.
4. The high-temperature filtration loss reducing agent according to claim 3, characterized in that, The thermally decomposable initiator is selected from one or more of benzoyl peroxide, dicumyl peroxide, ditert-butyl peroxide, dodecyl peroxide, tert-butyl peroxide, diisopropyl peroxide dicarbonate, dicarboxycyclohexyl peroxide, azobisisobutyronitrile, azobisisovalerate, and azobisisoheptanenitrile.
5. A method for preparing a high-temperature resistant filtration loss reducing agent as described in any one of claims 1 to 4, characterized in that, The method includes the following steps: S1. Add maleic anhydride, initiator, long-chain α-olefin and solvent in sequence, stir to dissolve, add isobutylene, and heat to react; S2. After cooling the reaction solution of S1 to room temperature, pour it into n-hexane to precipitate a solid. S3. Filter and wash the solid precipitated in S2, and dry and pulverize the washed solid to obtain the filtration loss reducer.
6. The preparation method of the high-temperature resistant filtration loss reducing agent according to claim 5, characterized in that, In S1, the inert gas is selected from one or more of nitrogen, helium, and argon.
7. The preparation method of the high-temperature resistant filtration loss reducer according to claim 5, characterized in that, In S1, the reaction temperature is 50~80℃; the reaction time is 3~6h.
8. The application of a high-temperature filtration reducing agent as described in any one of claims 1 to 4, or a high-temperature filtration reducing agent prepared by any one of claims 5 to 7, in a gas-to-oil synthetic drilling fluid.
9. A gas-to-oil synthetic drilling fluid, characterized in that, The gas-to-oil synthetic drilling fluid contains the high-temperature filtration reduction agent as described in any one of claims 1 to 4, or the high-temperature filtration reduction agent prepared by any one of the preparation methods described in claims 5 to 7.
10. An oilfield drilling technology, characterized in that, The drilling process uses the gas-to-oil synthetic drilling fluid as described in claim 9.