15 results about "Asphaltene precipitation" patented technology

This application provides a numerical simulation method, apparatus, and storage medium for asphaltene deposition unblocking, belonging to the field of oil and gas field development technology. The method includes: constructing a thermodynamic component model containing asphaltene based on reservoir fluid composition; calculating oil-solid phase equilibrium conditions using equations of state; setting a critical mole fraction for asphaltene precipitation in the oil phase, where precipitation occurs when the actual mole fraction is greater than or equal to the critical value; setting reaction paths for precipitation and unblocking reactions; establishing a porosity-permeability coupled evolution model, where porosity decreases linearly with solid deposition, and permeability decreases power-lawically with decreasing porosity; embedding the above model into a reservoir numerical simulator, and dynamically updating the asphaltene concentration, solid deposition, porosity, and permeability parameters of each grid through time-step numerical solutions.

The invention provides a method for calculating crude oil precipitation of an underground water-sealed cave depot. The method comprises the following steps: determining the content percentage of colloidal asphaltene in a crude oil sample to be stored; calculating the solubility of colloidal asphaltene in the crude oil sample by adopting PVTsim software; carrying out colloidal asphaltene precipitation experiments under different temperature and pressure conditions, and determining the supersaturation content of colloidal asphaltene in the crude oil sample according to the colloidal asphaltene precipitation experiments at different standing times; calculating the particle settling velocity of colloidal asphaltene in the crude oil sample; determining the precipitation volume of the colloidal asphaltene according to the particle sedimentation velocity, the supersaturation content, the solubility and the storage time of the colloidal asphaltene in the crude oil sample; and determining the precipitation thickness of the colloidal asphaltene in the oil storage cavern according to the precipitation volume of the colloidal asphaltene in the crude oil sample and the geometrical shape of the oil storage cavern of the underground water-sealed cavern. The method has the technical effect that the precipitation thickness of the colloidal asphaltene in the oil storage cavern of the underground water-sealed cavern can be accurately calculated.

The present application relates to the technical field of oilfield stimulation and reconstruction, and particularly relates to a biological composite plugging removal process for heterogeneous reservoirs, which comprises the following steps: (1) injecting a biological plugging removal fluid into an oil well; (2) injecting a diverting acid system into the oil well; (3) injecting the biological plugging removal fluid into the oil well; and (4) injecting a displacement fluid into the oil well. The biological plugging removal fluid first enters a high-permeability reservoir, effectively removes organic plugging caused by wax and asphaltene precipitation, and exposes inorganic impurities wrapped therein, which is beneficial to the subsequent dissolution of inorganic plugging by the diverting acid system. After the injection of the diverting acid system, the acid enters the high-permeability reservoir, effectively removes inorganic scale, and meets the needs of plugging removal in complex scale reservoirs of the oil well. With the acid-rock reaction, the viscosity of the acid system increases, temporarily plugs the high-permeability reservoir, forces the subsequent acid and biological plugging removal fluid to enter a low-permeability reservoir, so that the low-permeability oil layer is treated, and the needs of the heterogeneous oil well stimulation are met.

The present application belongs to the field of oil well asphaltene precipitation treatment, and particularly relates to a method for removing oil well asphaltene blockage and a maintenance method. After determining the target oil well where the wellbore asphaltene blockage occurs, the present application firstly adopts the single injection of asphaltene dissolving method to obtain the required amount of asphaltene dispersant, and then injects the solution containing the asphaltene dispersant into the target oil well where the wellbore asphaltene blockage occurs according to the smallest injection rate and injection pressure as possible, so as to dissolve the asphaltene and promote the oil well to restore self-flowing on the basis of causing as little additional pressure as possible. In the case that the single injection cannot make the oil well restore self-flowing, the continuous injection method is adopted, the solution containing the asphaltene dispersant is injected into the target oil well according to the daily injection amount according to the initial high and gradually down to stable rule, so as to achieve the effect of quickly dredging to tend to be stable. During the continuous injection process, the wellhead condition is observed in real time, and if the abnormality related to asphaltene blockage occurs, the corresponding measures are taken in time.

In general, in one aspect, embodiments relate to a method, that includes lowering a downhole tool to a target depth of a wellbore, sampling reservoir fluid containing asphaltene at the target depth using the downhole tool, controlling a pressure of the sampled reservoir fluid while downhole to induce one or more phase transitions of the asphaltene, measuring the sampled reservoir fluid after inducing the one or more phase transitions, and identifying fluid composition of the reservoir fluid based on the measuring.

Fluid modeling methods and systems are provided for predicting phase behavior of petroleum fluids using a computational model that employs pseudo-components of varying carbon numbers that represent asphaltenes, asphaltene-like hydrocarbon, and non-asphaltene hydrocarbons. The computational model models the phase equilibria of the mixture of components with mixing rules that employ binary interaction parameters determined from correlations that involve certain properties or parameters associated with respective pseudo-component pairs as input variables. The binary interaction parameters are tuned by adjusting at least one parameter of the respective correlations based on matching at least one measured property of one or more petroleum fluids to a corresponding property predicted by the computational model for the one or more petroleum fluids. The tuned values for the binary interaction parameters can be stored as part of the computational model for subsequent fluid modeling. In embodiments, the computational model is based on the Advanced Peng Robinson equation of state.

This invention relates to a stabilizer for inhibiting asphaltene precipitation, its preparation method, and its application, comprising: X being an aromatic core, wherein the aromatic core is a polyaromatic amine or a heterocyclic aromatic core; L1 and L2 being connecting chains that are independently C2-C6 alkylene chains; and Y being a C8-C6 alkylene chain. 20 The asphaltenes are composed of straight-chain or branched alkyl, alkoxy, or alkyl ester groups; R¹ is an optional polarity regulating group selected from -COOR², -SO2R², and -CONHR², where R² is a C1-C6 alkyl group; n=2~6, m=3~9. This invention achieves recognition and encapsulation of asphaltenes molecules through π-π interactions between the large π-conjugated structure and the fused-ring aromatic hydrocarbons of asphaltenes. The connecting chain links the aromatic core and end groups, regulating the spatial topology of the molecule and avoiding excessive branching.

The invention belongs to the field of oil and gas field surface engineering, and discloses an ultra-heavy oil asphaltene subcomponent separation method, which comprises the following steps: dividing crude oil into three components, namely oil, colloid and asphaltene, separating asphaltene from turbid liquid of green matter precipitates or colloid precipitates under different toluene or acetone concentrations by changing the proportion of toluene to acetone, standing, centrifuging, and separating the asphaltene from the turbid liquid of the green matter precipitates or the colloid precipitates under different toluene or acetone concentrations; and pouring out the supernatant, and carrying out vacuum drying to respectively obtain different subcomponents of the asphalt. By changing the proportion of toluene and acetone, asphaltene precipitates under different toluene or acetone concentrations are obtained, five subcomponents of asphaltene can be obtained respectively, the effect of asphaltene without using subcomponents can be reflected more intuitively and clearly, and the method has the advantages of simplicity, convenience and rapidness in operation. The development of the asphaltene subcomponent separation technology provides important information for further research and application of asphalt materials, and also provides important technical support for analysis and evaluation of the quality of petroleum asphalt.

The application provides a carbon dioxide drive asphaltene deposition numerical simulation method, device and storage medium. The method comprises the following steps: obtaining basic physical property data of a target asphalt sample, and dividing the target asphalt sample into a first pseudo-component that is soluble in low molecular saturated hydrocarbon and a second pseudo-component that is insoluble in low molecular saturated hydrocarbon; determining the physical property parameters of the first pseudo-component through an experiment, and inversely calculating the physical property parameters of the second pseudo-component by using a mixing law in combination with the basic physical properties of the sample; obtaining asphaltene deposition experimental data of the sample under different temperatures, pressures and CO2 concentrations, calculating the molar fraction of the second pseudo-component in a fluid phase after deposition, and determining a solid-liquid equilibrium K value as the ratio of the molar fraction of the second pseudo-component to the molar fraction of 1 in a solid phase; introducing the K value into a reservoir numerical simulator, establishing a multi-phase and multi-component model based on mass conservation and multi-phase percolation equations, coupling a porosity and permeability dynamic change model, and predicting asphaltene deposition behavior in a CO2 drive process and the influence of the asphaltene deposition behavior on reservoir physical properties.

The invention discloses an asphaltene precipitation inhibitor, which is characterized in that the asphaltene precipitation inhibitor is a maleic anhydride-co-high-carbon alkene polymer with an amino aromatic heterocyclic side chain, and has a structural formula shown as a formula (I), in the formula, m is selected from 16, 18, 20 or 22; r is an aromatic heterocyclic ring with an amino group. The invention also discloses a preparation method and application thereof. The asphaltene inhibition effect of the aromatic heterocyclic ring with the amino group in an aromatic group is obviously superior to that of other aromatic groups.

The invention discloses a crude oil asphaltene solid inhibitor and a preparation method and application thereof, the preparation method comprises the following steps: reacting palmitoleic acid, aluminum oxide and diethylenetriamine, then reacting with ethidene diamine under the action of ethanol, and dissolving the obtained reactant and clay in water to obtain a mixture; and adding vinyl acetate into the mixture, uniformly stirring, adding cyclohexane, vinyl alcohol polyether and an initiator, uniformly mixing, and carrying out polymerization reaction to obtain the crude oil asphaltene solid inhibitor. The prepared crude oil asphaltene solid inhibitor can reduce the crude oil asphaltene precipitation temperature by 7-13 DEG C, and still has a good asphaltene precipitation inhibition function under the condition that the use concentration is reduced.

The application discloses an evaluation device and method for asphaltene dispersion inhibitors, and belongs to the technical field of oil and gas field development. The evaluation method of the evaluation device for asphaltene dispersion inhibitors adopts oil samples containing and not containing asphaltene dispersion inhibitors to simulate the pressure reduction process in the crude oil exploitation process, uses a spectrometer to obtain backscattering signals in the two processes, and evaluates the inhibiting effect of the asphaltene dispersion inhibitor based on the changes of the two backscattering signals and time. The asphaltene dispersion inhibitor suitable for high-temperature and high-pressure conditions, with stable performance and inhibiting and dissolving effects on asphaltene precipitation, can be screened out for high-temperature and high-pressure oil wells. Through the evaluation method, technical support is provided for the screening of agents for high-temperature and high-pressure oil wells and the prevention and treatment of asphaltene precipitation, so that the efficient exploitation of high-temperature and high-pressure oil wells is ensured.

The application discloses asphalt-based wax-proofing agent and its preparation method and application. The preparation method comprises the following steps: (1) heating and melting the vacuum residue and the deoiled asphalt, adding them into a reaction kettle, adding a raw material modifier, and performing modification treatment under a protective gas; (2) after the obtained material is cooled, extracting an asphaltene component, obtaining a deasphaltene raw material, and separating a gum component; (3) mixing an asphaltene precipitation agent and an asphaltene dispersant to obtain an asphaltene extraction agent, mixing the asphaltene extraction agent with the asphaltene, filtering, drying, and obtaining solid substance A1; (4) continuously adding the asphaltene precipitation agent into the filtrate to obtain solid substance A2; (5) mixing the solid substance A1 with the gum component to obtain an asphaltene mixed component, mixing the asphaltene mixed component with a reaction activator and dimethylbenzene, adding the solid substance A2, and obtaining the asphalt-based wax-proofing agent. The wax-proofing agent can significantly reduce the wax deposition amount, has excellent performance and low cost, and can prolong the hydrate generation time and inhibit the generation of hydrates.

In general, in one aspect, embodiments relate to a method, that includes lowering a downhole tool to a target depth of a wellbore, sampling reservoir fluid containing asphaltene at the target depth using the downhole tool, controlling a pressure of the sampled reservoir fluid while downhole to induce one or more phase transitions of the asphaltene, measuring the sampled reservoir fluid after inducing the one or more phase transitions, and identifying fluid composition of the reservoir fluid based on the measuring.

The invention discloses an inhibitor as well as a preparation method and application thereof, and relates to the technical field of petrochemical engineering. The inhibitor comprises a structural unit derived from a monomer as shown in a formula I, a structural unit derived from a monomer as shown in a formula II and a structural unit derived from 2-acrylamide-2-methylpropanesulfonic acid, wherein R1 and R2 are respectively and independently one of C12-22 alkyl and C12-22 halogenated alkyl. The inhibitor containing the three structural units has the effects of inhibiting formation of paraffin and asphaltene precipitates, and is suitable for being applied to the field of oilfield chemical industry.