51 results about "Carbon dioxide corrosion" patented technology

The present application relates to the technical field of metallurgy, and particularly relates to a production method of a large-wall-thickness pipeline steel with improved carbon dioxide corrosion resistance and strength and toughness, and specific measures include: (1) controlling the bottom blowing mode and end point requirement in the converter process; (2) controlling the tapping time and replacing the tapping hole opportunity in the tapping process; (3) feeding the CAS aluminum wire and controlling the CAS argon blowing time; (4) controlling the top slag addition amount, heating time and outgoing mode in the LF refining process; (5) controlling the wire feeding parameters, soft blowing time and outgoing requirement of RH in the RH refining process; (6) controlling the precision requirement, casting speed fluctuation and crystallizer liquid level fluctuation of the continuous casting equipment in the continuous casting process to obtain the casting blank. Through controlling the parameters of each process in the smelting and rolling process, the present application realizes the whole-process steel cleanliness control and ladle grain refinement, and further improves the strength, low-temperature toughness, HIC resistance and carbon dioxide corrosion resistance of the large-wall-thickness pipeline steel.

The invention discloses a resin well cementation method for a carbon dioxide injection well, which comprises the following steps of: calculating the annulus volume between a small-diameter casing string and an original well casing according to the specification parameters of the casing; a well killing hydraulic well is used, and after well killing is completed, the small-diameter casing string is lowered to the preset depth, and then a well mouth is installed; the method comprises the following steps: injecting a first solution into an annulus between a small-diameter casing string and an original well casing until well killing fluid in the annulus and the small-diameter casing is completely replaced by the first solution; after well killing fluid replacement is completed, a second solution with the same volume as the annulus volume is injected into the small-diameter casing string, the density of the second solution and the density of the first solution are close and both smaller than the density of the well killing fluid, the second solution and the first solution are different in color, and a high-strength carbon dioxide corrosion resistant resin slug is injected into the annulus pump; the technical problem of resin well cementation in the overflow state of the carbon dioxide injection well is solved.

The present invention relates to the technical field of preparation of oilfield chemical additives, and is an oil-based annular space protection fluid and a preparation method thereof. The raw materials of the former include, by mass percentage, 1% to 2% of an anti-carbon dioxide corrosion inhibitor, 1% to 2% of a polycyclic azide structure desulfurizer, 1% to 2% of an oil-soluble polymerized guanidine bactericide, 1% to 10% of a surfactant, and the rest is organic oil. The latter is prepared according to the following method: adding the required amount of an anti-carbon dioxide corrosion inhibitor, a polycyclic azide structure desulfurizer, an oil-soluble polymerized guanidine bactericide, and a surfactant to the organic oil, mixing and stirring to obtain an oil-based annular space protection fluid. The preparation process of the present invention is simple, and the obtained oil-based annular space protection fluid has the dual effects of corrosion inhibition and sterilization, good thermal stability, strong high temperature resistance, and is suitable for highly acidic gas environments. It also has low corrosion performance on carbon steel pipes and good anti-corrosion effect. At the same time, the organic oil used does not contain aromatic hydrocarbons, and has the advantages of being non-toxic, low-cost, and renewable.

The application provides an anti-carbon dioxide corrosion inhibitor, a preparation method and application thereof, and relates to the technical field of oil and gas field corrosion protection. The application provides an inhibitor, raw materials of which include alpha-lipoic acid, diethylene triamine, formaldehyde, 2-naphthyl ethyl ketone and benzyl chloride in a molar ratio of 1.0-1.2:0.8-1.2:1.2-2.0:1.0-1.4:1.0-1.4. The application also provides a preparation method, raw materials are taken according to the molar ratio, alpha-lipoic acid and diethylene triamine are mixed to obtain a first product through reaction; formaldehyde and 2-naphthyl ethyl ketone are mixed with the first product to obtain a second product through reaction; benzyl chloride and the second product are mixed to obtain a finished product inhibitor through reaction. The application also provides application of the inhibitor in preventing carbon dioxide corrosion. The inhibitor has good corrosion inhibition effect, a simple preparation method, a stable structure, and still has superior corrosion inhibition effect in a high salinity environment.

This invention relates to the field of rolled steel pipe processing, specifically a method for manufacturing a stainless steel cooling pipe. The stainless steel cooling pipe is grade 022Cr17Ni12Mo2, with the following chemical composition by weight percentage: C 0.010~0.020, Si<0.50, Mn<2.00, Cr 16.50~17.50, Ni 10.50~11.50, Mo 2.00~3.00, S<0.015, P<0.030. A typical specification is Φ25×2mm. The manufacturing method includes: (i) billet manufacturing; (ii) hot extrusion; (iii) cold rolling; (iv) heat treatment; (v) straightening; and (vi) surface treatment. The finished tube has a low-temperature elongation of ≥50% (0℃), an inner surface roughness Ra≤0.8μm, an outer surface roughness of 6.3μm>Ra≥3.2μm, a uniform microstructure, a grain size of 5~6 grade, and a thermal conductivity ≥17.6 W(m·K). ‑1 (0℃), carbon dioxide corrosion rate <0.05 mm / a (CO2 partial pressure 0.1MPa).

The invention belongs to the technical field of petroleum well cementation simulation tests, and discloses a simulation experiment device and method for dynamic corrosion of carbon dioxide to well cementation cement stone. The simulation experiment device comprises a kettle body, a liquid carbon dioxide bottle and a carbon dioxide recovery bottle, the kettle body is provided with an upper end opening, a lower end opening and a containing cavity, the upper end opening and the lower end opening are communicated with the upper end and the lower end of the containing cavity respectively, and a test combination body is placed in the containing cavity. The test assembly comprises a rock core, and set cement and a sleeve which are sequentially arranged on the outer side of the rock core in a sleeving manner; the liquid carbon dioxide bottle is connected with the upper port through a liquid inlet pipe so as to inject liquid carbon dioxide into the containing cavity, and a booster pump is arranged on the liquid inlet pipe. The carbon dioxide recovery bottle is connected with the lower port through a liquid return pipe to recover liquid carbon dioxide, and a pressure limiting valve is arranged on the liquid return pipe. According to the invention, the flowing of carbon dioxide in the stratum and the corrosion simulation of the cement stone at the well cementation interface are realized, and the actual working condition that the cement stone is corroded by carbon dioxide under the stratum condition is more truly reduced.

The present application relates to a kind of experimental equipment, in particular to a kind of carbon dioxide corrosion experiment device, including reactor, reactor heating assembly, reactor heating assembly is used to segment heating for the reactor, so that the reactor is divided into first temperature section, second temperature section, third temperature section, first temperature section, second temperature section, third temperature section are respectively provided with first window, second window, third window on the side wall, first window, second window, third window are respectively provided with optical observation equipment and corrosion detection probe, the bottom of the reactor is connected with liquid inlet pipe, gas inlet pipe, the top of the reactor is provided with fourth window, gas outlet, the sample holder is set in the reactor, the sample holder is used to place sample, the sample holder is through first temperature section, second temperature section, third temperature section of the reactor.The present application can carry out carbon dioxide corrosion behavior experiment under multiple phase states.

According to the X65 pipeline steel for conveying supercritical carbon dioxide and the manufacturing method of the X65 pipeline steel, the production process is simple, existing metallurgical equipment, steel rolling equipment and cooling equipment do not need to be updated, additional equipment does not need to be added, and industrial production can be directly conducted. The low-temperature crack initiation and crack arrest toughness of the steel plate can be greatly improved, the carbon dioxide corrosion resistance can be greatly improved, and large economic benefits are produced.

The application relates to the technical field of steel production, in particular to a carbon dioxide corrosion-resistant steel and a preparation method thereof.The chemical components of the steel include C, Cr, Mn, Nb, Si, P, S and Fe; wherein the content of C is 0.05-0.15 wt%, the content of Cr is 1-3 wt%, the content of Mn is 1-1.5 wt%, the content of Nb is 0.025-0.055 wt%, the content of Si is 0.2-0.3 wt%, the content of P is <=0.008 wt%, and the content of S is <=0.002 wt%. The application solves the technical problem that the existing steel has poor carbon dioxide corrosion resistance.

The invention relates to the technical field of oil and gas well cementing cement paste, in particular to carbon dioxide corrosion resistant cement paste and a preparation method thereof. Wherein the cement paste is prepared from the following preparation raw materials in parts by weight: 800 parts of cement, 40 to 80 parts of nano-particle filler, 2 to 15 parts of flaky filler, 1 to 10 parts of surfactant, 1 to 8 parts of defoaming agent, 20 to 50 parts of fluid loss agent, 0.5 to 5.5 parts of dispersing agent, 0.5 to 6.5 parts of retarder and 200 to 500 parts of water. The carbon dioxide corrosion resistant cement paste provided by the invention not only can significantly improve the corrosion resistance of set cement formed after the cement paste is cured, but also can help to improve the mechanical strength of the set cement to oil and gas wells and improve the sealing capacity.

The invention discloses high-strength carbon-dioxide-corrosion-resistant stainless steel which comprises, by mass, 2%-3% of Mo, smaller than or equal to 0.5% of Si, smaller than or equal to 0.03% of C, 18%-20% of Cr, 7%-8% of Ni, 4.0%-5.0% of Mn, 1.5%-2.0% of Al, 0.3%-0.5% of V and the balance Fe and inevitable impurities. A preparation method of the high-strength carbon-dioxide-corrosion-resistant stainless steel comprises the following steps that raw materials are added into an electric arc furnace to be smelted; atomizing into spherical metal powder; oxidizing the pretreated metal powder; performing spark plasma sintering; performing hot extrusion, liquid nitrogen subzero treatment, warm rolling and annealing to obtain stainless steel; the stainless steel is completely immersed in the modifier for 30 min, and the stainless steel resistant to carbon dioxide corrosion is obtained; the modifier comprises a silane coupling agent, rare earth salt, sodium molybdate and benzotriazole. The stainless steel prepared from the components through the preparation method has high strength and carbon dioxide corrosion resistance.

According to the preparation method of the carbon dioxide corrosion prevention material and the corresponding cement paste system, the kaolin with the kaolinite mineral content larger than 95% is subjected to ultrasonic dispersion in water, the kaolin suspension liquid is obtained, the kaolin suspension liquid added with the intercalator is sequentially subjected to centrifugal dispersion, dehydration and superfine wet grinding treatment, and the carbon dioxide corrosion prevention material is obtained. The preparation method comprises the following steps: preparing a micro-nano kaolin material, calcining the micro-nano kaolin material at a high temperature to obtain micro-nano metakaolin, and mixing the micro-nano metakaolin and micro-nano silicon dioxide powder according to a preset ratio to obtain the carbon dioxide corrosion prevention material. According to the technical scheme, the adopted kaolin has stability and chemical inertness at high temperature, the kaolin is subjected to ultrasonic dispersion, centrifugal dispersion, high-temperature calcination and other treatments to obtain micro-nano metakaolin which is uniform in distribution and high in durability, and then the micro-nano metakaolin is mixed with silicon dioxide to prepare the material with high carbon dioxide corrosion resistance.

This utility model discloses a high-sealing, carbon dioxide corrosion-resistant, heat-insulating oil casing, specifically relating to the field of heat-insulating oil casing technology. It includes a pipe body and a coupling. The coupling is threadedly connected to the outer end of the pipe body. A fixing plate is fixedly installed on one side of the outer surface of the pipe body. The fixing plate has multiple fixing holes inside, and two springs are fixedly installed on the inner top surface of each fixing hole. In practical operation, the end of the pipe body is inserted into the coupling and rotated to achieve a threaded connection. Under the elastic action of the springs, a limiting hook extends to the side outside the fixing hole and inserts into the limiting hole of the connecting plate, thus engaging with the threaded connection to assemble and connect the pipe body and the coupling. The elastic force of the springs provides continuous clamping force, effectively offsetting the preload attenuation caused by vibration. The insertion and engagement of the limiting hook and the limiting hole further restricts axial displacement, effectively preventing loosening between the pipe body and the coupling from affecting the transport of heavy oil.

The invention discloses anti-fatigue carbon dioxide corrosion-resistant well cementation cement paste as well as a preparation method and application thereof. The well cementation cement paste is prepared from the following raw materials in parts by weight: 90 to 100 parts of oil well cement, 8 to 15 parts of carbon dioxide modified superfine slag powder, 5 to 12 parts of stress buffering agent, 0.4 to 0.8 part of fiber toughening agent, 0.5 to 3 parts of dispersing agent, 1.5 to 2.5 parts of fluid loss agent and 40 to 50 parts of water. Wherein the stress buffering agent is a polymer microsphere with a core-shell structure, the inner core is a styrene-butadiene copolymer, the outer shell is an epoxy resin grafting layer, and the average particle size of the stress buffering agent is 20-50 [mu] m. Set cement formed after the well cementation cement slurry is solidified has excellent impact toughness, stress buffering capability and carbon dioxide corrosion resistance.

The invention relates to manufacturing of a pipeline steel hot-rolled coiled plate for a longitudinal welded pipe, in particular to 450MPa-grade carbon dioxide corrosion resistant steel and a manufacturing method of the 450MPa-grade carbon dioxide corrosion resistant steel. The steel comprises the following chemical components: C, Si, Mn, less than or equal to 0.020% of P, less than or equal to 0.002% of S, less than or equal to 0.008% of Cr, Cu, V, Ti, Al, less than or equal to 0.008% of N and the balance of Fe and inevitable elements. According to the steel plate, the transverse yield strength is 470 MPa or above, the tensile strength is 580 MPa or above, the yield ratio is smaller than or equal to 0.87, the elongation A50 mm is larger than or equal to 39%, the impact energy at the temperature of-40 DEG C is 280 J or above, the drop weight at the temperature of-20 DEG C is larger than or equal to 95%, and according to the ASTM-G111 corrosion standard, the average corrosion rate in the carbon dioxide environment is smaller than 0.10 mm / a; the longitudinal yield strength is 460 MPa or above, the tensile strength is 570 MPa or above, the yield ratio is smaller than or equal to 0.86, and the elongation A50 mm is larger than or equal to 38%.

The invention relates to the technical field of preparation of oilfield chemical assistants, in particular to an anti-carbon dioxide corrosion inhibitor and a preparation method and application thereof.The anti-carbon dioxide corrosion inhibitor is obtained by mixing and compounding a first polymer, a second polymer and modified imidazoline according to the required amount, the second polymer is imidazoline with a linear structure. According to the corrosion inhibitor, n imidazoline rings in molecules of the first polymer are adsorbed on a stainless steel pipe, the adsorption capacity and the scouring resistance of the corrosion inhibitor are improved, the adsorbability of imidazoline is improved through the second polymer, the hydrophobic capacity of monocyclic imidazoline is improved by introducing a primary amine hydrophobic group into the modified imidazoline, the water phase is further inhibited from making contact with the metal surface, and the corrosion inhibitor has a good corrosion inhibition effect on the stainless steel pipe. Meanwhile, a guanidine structure is introduced into an imidazoline structure, so that the product has a strong sterilization effect, and a polymer chain structure contains a carboxylic acid structure, so that the product has relatively strong capability of complexing cations such as calcium and magnesium, and the scaling problem caused by carbon dioxide can be effectively inhibited.

The invention discloses a titanium alloy pipe suitable for geothermal resource exploitation and a manufacturing method. The titanium alloy pipe comprises the following components in percentage by weight: 3.0-5.0% of Al, 1.5-3.5% of V, 0.5-2.0% of Mo, 1.0-2.0% of Fe, 0.1-0.3% of Nb, 0.05-0.15% of Ru, 0.08-0.15% of O, less than or equal to 0.015% of C, less than or equal to 0.015% of H, less than or equal to 0.02% of N and the balance of Ti and other inevitable impurities. And the contents of the elements must simultaneously meet the following relation: Nb / Ru is greater than or equal to 2 and less than or equal to 5. The room-temperature yield strength of the obtained titanium alloy pipe is larger than or equal to 760 MPa, the yield strength at 450 DEG C is reduced by less than 25% compared with the room-temperature yield strength, the transverse Charpy impact energy at-10 DEG C is larger than or equal to 40 J, and the titanium alloy pipe has good oxygen corrosion resistance and hydrogen sulfide and carbon dioxide corrosion resistance, is at the high temperature of 450 DEG C and is rich in O2, H2S, CO2 and water vapor (so called rich, H2S, CO2 and water vapor). And the corrosion rate is less than 0.25 mm / a under the environment corrosion test condition that the gas volume fraction is not less than 1%.

The present application relates to the technical field of foam cementing of oil and gas wells, and discloses a carbon dioxide corrosion-resistant foam cement slurry and a preparation method thereof. The raw material composition comprises cement, siliceous material, corrosion-resistant material, toughening and expanding material, fluid loss additive, retarder, drag reducing agent, foaming agent, foam stabilizer and water in terms of mass parts. The required amount of cement, siliceous material and corrosion-resistant material is mixed to obtain a solid phase material. The required amount of water is added with the fluid loss additive, retarder and drag reducing agent in sequence, and stirred respectively. Then, the foaming agent and foam stabilizer are added in sequence, and stirred uniformly to obtain a slurry preparation liquid. Finally, the solid phase material is added into the slurry preparation liquid and stirred to obtain the carbon dioxide corrosion-resistant foam cement slurry. The present application can reduce the permeability of cement stone, reduce the corrosion channeling passage, improve the compressive strength, toughness, cementing strength and corrosion resistance of low-density cement stone, and realize efficient CO2 storage and cyclic reinjection, which is green and environmentally friendly.

The invention relates to the technical field of petroleum drilling engineering, and discloses a carbon dioxide fracturing working condition cement sheath integrity evaluation device and method. The inner sleeve simulation fracturing high-pressure control system, the cement sheath simulation carbon dioxide corrosion pressurization high-pressure control system, the outer sleeve simulation stratum confining pressure high-pressure control system, the water and gas channeling detection system and the heating system are connected with the cement sheath stratum combination body. According to the invention, the process of actual damage to the cement sheath under the condition of coupling of actual carbon dioxide fracturing alternating stress and supercritical carbon dioxide corrosion can be simulated, a design basis is provided for a cement slurry system of coal rock gas carbon dioxide front energy storage fracturing, and the integrity of the cement sheath developed by deep coal rock gas fracturing is improved; therefore, the deep coal rock gas yield is effectively improved.

The invention provides an automatic control method for simulating a carbon dioxide corrosion reaction of an oil and gas reservoir. The control method comprises the following steps: S1, establishing a mathematical model for realizing a permeation mechanism; s2, compiling a user-defined script according to the mathematical model; s3, after numerical simulation initialization is completed, pausing and executing the custom code; s4, calculating an intermediate variable and outputting the intermediate variable to numerical simulation software; s5, starting numerical simulation of the next time step; and S6, repeating the steps S1 to S5 until the simulation is finished. According to the method for rapidly realizing the percolation mechanism through the oil and gas reservoir numerical simulation custom script, when the new percolation mechanism is added, source codes of numerical simulation software do not need to be modified, the difficulty of realizing a new percolation mechanism model is reduced, and the efficiency of adding the new percolation mechanism into the numerical simulation software is improved.

A method for producing L360MC supercritical carbon dioxide corrosion-resistant steel plate. The chemical composition of the steel is as follows: C = 0.01% to 0.02%, Si = 0.10% to 0.30%, Mn = 0.70% to 0.90%, P ≤ 0.008%, S ≤ 0.0015%, Alt = 0.020% to 0.050%, Nb = 0.025% to 0.045%, Cr = 0.90% to 1.10%, Ti = 0.010% to 0.020%, Mo = 0.10% to 0.15%, with the remainder being Fe and unavoidable impurities. The steel plate has a multiphase structure of ferrite + pearlite and a small amount of MA. The present invention adopts a low-carbon, low-manganese, medium-chromium composition design, continuously casts into billets, and produces steel plates through the TMCP process. The steel plate has properties that combine strength, high toughness at low temperatures, low-temperature crack arrest, and high-pressure carbon dioxide corrosion resistance.

The present application relates to the technical field of oilfield chemistry, and is an emulsion type annulus protection fluid and a preparation method thereof, which comprises, in terms of mass percentage, 1-2% of anti-carbon dioxide corrosion inhibitor, 1-2% of sulfur removal agent, 1-2% of bactericide, 1-5% of surfactant, 40-60% of organic oil, 0.1-2% of emulsion polymer stabilizer and 5-50% of water, and is prepared by the following method: adding the required amounts of anti-carbon dioxide corrosion inhibitor, sulfur removal agent, bactericide, surfactant, emulsion polymer stabilizer and water into the required amount of organic oil, and then mixing and stirring to obtain the emulsion type annulus protection fluid. The present application has the advantages of simple preparation process, good corrosion protection effect, good protection effect on the wellbore string of a well containing carbon dioxide and hydrogen sulfide, and the use of organic oil as a continuous phase to form a water-in-oil stable emulsion, which can not only retain the characteristics of oil-based products, but also greatly reduce the cost.

The invention provides a CO2-rich phase corrosion prediction method based on a random forest and an improved ACE algorithm, and relates to the technical field of corrosion prediction.The CO2-rich phase corrosion prediction method comprises the steps that corrosion influence data and corresponding corrosion rate data are collected, and a comprehensive database is established; based on the comprehensive database, analyzing the influence degree of each corrosion influence parameter on the corrosion rate to obtain influence degree data of different corrosion influence parameters on the corrosion rate; and establishing a carbon dioxide corrosion prediction model through the influence degree data and the comprehensive database. According to the invention, the applicable working conditions are wider: the CO2 conveying phase state is wider, and the system is suitable for various conveying phase state working conditions such as a gaseous state, a liquid state and a supercritical state; according to the invention, the impurity types are wider, and the method is suitable for the working conditions of impurities containing SO2, O2, H2O, H2S and NO2. Compared with a prediction model and other machine learning algorithm models in a traditional oil gas and transmission environment, the method is higher in prediction precision.

The application relates to the technical field of valve manufacturing, and discloses a corrosion-resistant ball valve for a deep-sea carbon dioxide storage injection well mouth, which comprises a main body, and a feeding opening is arranged in the main body. In the process that the rotating ball continues to rotate, the arc-shaped plate is in an inclined state at the moment, the side wall of the through groove located in the rotating ball is in contact with the side edge of the arc-shaped plate, the outer surface of the rotating ball completely seals the inlet of the main body, then the arc-shaped plate is pushed to rotate on the inner wall of the main body when the rotating ball continues to rotate, the closing of the valve is completed, the situation that part of fluid enters the inside of the main body and cannot be discharged when the rotating ball rotates, which leads to excessive corrosion of the external connecting part of the rotating ball, is avoided, the corrosion degree of the internal connecting part of the device caused by carbon dioxide is reduced, and the sealing quality of the valve for deep-sea carbon dioxide is improved.

The present application relates to a kind of manufacture of pipeline steel hot-rolled coil for straight seam welded pipe, especially 450MPa grade carbon dioxide corrosion resistant steel and its manufacturing method.The chemical composition in steel contains:C, Si, Mn, P≤0.020%, S≤0.002%, Cr, Cu, V, Ti, Al, N≤0.008%, the rest is Fe and inevitable element.The transverse yield strength of steel plate is 470MPa or more, tensile strength is 580MPa or more, yield ratio≤0.87, elongation A 50mm ≥39%, impact energy at-40 ℃ is 280J or more, drop hammer at-20 ℃≥95%, according to ASTM-G111 corrosion standard, average corrosion rate in carbon dioxide environment is less than 0.10mm / a;Longitudinal yield strength is 460MPa or more, tensile strength is 570MPa or more, yield ratio≤0.86, elongation A 50mm ≥38%.

The present application relates to oil field chemical additive preparation technical field, it is a kind of carbon dioxide-resistant corrosion inhibitor and its preparation method and application, after the required amount first polymer, second polymer and modified imidazoline are mixed, carbon dioxide-resistant corrosion inhibitor is obtained, wherein, first polymer is comb structure imidazoline, second polymer is linear structure imidazoline.The n imidazolin ring in the first polymer molecule is adsorbed on stainless steel pipe, the adsorption capacity and the scouring performance of corrosion inhibitor are improved, the adsorption of second polymer increases imidazoline, modified imidazoline is introduced by primary amine hydrophobic group, the hydrophobic capacity of monocyclic imidazoline is improved, water phase contact metal surface is further inhibited, and guanidine structure is introduced in imidazolin structure, so that product has strong bactericidal efficacy, polymer chain structure contains carboxylic acid structure, so it has strong complexing calcium, magnesium and other cation ability, can effectively inhibit the problem of carbon dioxide caused by fouling.

The application discloses a bactericidal corrosion inhibitor and a preparation method and application thereof. The bactericidal corrosion inhibitor comprises the following components in percentage by weight: 10-90% of a compound of formula (I), 10-90% of an organic polar solvent, 0-20% of an additive, and the balance of water; the bactericidal corrosion inhibitor can be quickly adsorbed on the metal surface and the bacterial surface, has good corrosion inhibition, bactericidal and bacteriostatic capacities, can control the corrosion rate mainly caused by hydrogen sulfide corrosion or carbon dioxide corrosion to be below 0.076 mm / a, and can effectively kill sulfate-reducing bacteria (SRB) with a bactericidal rate of more than 99%.

The application discloses a high-strength oil casing pipe with carbon dioxide corrosion resistance, which contains Fe and inevitable impurities, and additionally contains the following chemical elements: C: 0.10-0.20%, Si: 0.10-0.80%, Mn: 0.10-1.50%, Cr: 3-5%, Mo: 0.10-0.70%, Al: 0.01-0.10%, V: 0.10-0.20%, Ni: 0.1-1.0%, Ce: 0.002-0.01%, and La: 0.002-0.01%. Correspondingly, the application also discloses a manufacturing method of the high-strength oil casing pipe with carbon dioxide corrosion resistance. The oil casing pipe with super-high strength and excellent carbon dioxide corrosion resistance can be obtained through reasonable chemical element component design.

The invention relates to the technical field of oilfield chemistry, in particular to an emulsion type annulus protection fluid and a preparation method thereof.The emulsion type annulus protection fluid is prepared from, by mass, 1%-2% of a carbon dioxide corrosion inhibitor, 1%-2% of a sulfur removal agent, 1%-2% of a bactericide, 1%-5% of a surfactant, 40%-60% of organic oil, 0.1%-2% of an emulsion polymer stabilizer and 5%-50% of water; the emulsion type annulus protection liquid is prepared according to the following method: adding a required amount of a carbon dioxide-resistant corrosion inhibitor, a sulfur removal agent, a bactericide, a surfactant, an emulsion polymer stabilizer and water into a required amount of organic oil, and mixing and stirring to obtain the emulsion type annulus protection liquid. The preparation process is simple, the anti-corrosion effect is good, a good protection effect on a shaft pipe column of a well containing carbon dioxide and hydrogen sulfide is achieved, meanwhile, organic oil is used as a continuous phase, a water-in-oil stable emulsion is formed, the characteristics of an oil-based product can be reserved, and the cost can be greatly reduced.

The present application relates to a kind of pipeline steel hot-rolled coil for straight seam welded pipe, especially to a kind of high crack arrest toughness carbon dioxide corrosion resistant pipeline steel and its manufacturing method.The chemical composition in steel contains:C, Si, Mn, P≤0.010%, S≤0.002%, Mo, Nb, Ti, Al, Co, N≤0.008%, the rest is Fe and inevitable element.The transverse yield strength of the steel plate of the present application is 490MPa or more, the tensile strength is 600MPa or more, the yield ratio is ≤0.86, the elongation A 50mm ≥37%, the impact energy at-40 ℃ is 350J or more, the drop hammer at-20 ℃ is ≥95%, the average corrosion rate in carbon dioxide environment is <0.08mm / a;The longitudinal yield strength is 485MPa or more, the tensile strength is 590MPa or more, the yield ratio is ≤0.85, the elongation A 50mm ≥41%.