59 results about "Geochemistry" patented technology

The invention relates to the technical field of oil-gas exploration, in particular to a hydrocarbon generation potential evaluation method for marine hydrocarbon source rocks. On the basis of determining terrestrial source and sea source organic matter proportions of marine facies hydrocarbon source rocks in different sedimentary areas, marine facies hydrocarbon source rock thermal simulation experiments of different terrestrial source / sea source organic matter proportions are carried out, and gaseous hydrocarbon yields of the marine facies hydrocarbon source rocks of different terrestrial source / sea source organic matter proportions and isotope characteristics and activation energy of gaseous hydrocarbons of different maturity degrees are determined; according to generation, storage and cover layer parameters of a research area, selecting a suitable model and giving suitable parameter values, performing numerical simulation on hydrocarbon source rocks with different terrestrial / sea source organic matter proportions, and finally quantitatively determining hydrocarbon generation potential of hydrocarbon source rocks with different sedimentary areas and different terrestrial / sea source organic matter proportions in the research area by combining burial-thermal history evolution of the research area. And obtaining a hydrocarbon generation and expulsion period and a charging process, and determining a main reservoir forming period. Compared with the prior art, the hydrocarbon generation potential evaluation accuracy of the marine hydrocarbon source rock can be greatly improved.

Low CAPEX / OPEX, effective, and environmentally friendly process of rapidly extracting lithium from geothermal brines and producing lithium carbonate. The method includes adjusting a unique parameter determined based on the modified alkalinity in a quantity of the geothermal brine to a preset value without needing to purposefully modify the pH. Interactions of the anionic reactant species with components within the geothermal brine cause a solid form of the lithium to precipitate out of the geothermal brine. After the solid separation, the spent brine is environmentally safe and returned underground or transported to a reservoir.

The invention discloses a semi-quantitative analysis-based target area optimization method for exploration of hydrothermal geothermal resources, which relates to the field of hydrothermal geothermal resources, and comprises the following steps: determining a calculation range, carrying out index division on sedimentary basin type geothermal resources, upheaval mountain convection type geothermal resources, hot spring geothermal resources and county geothermal resources, carrying out basic parameter selection on secondary indexes, and carrying out target area optimization. And geothermal resource potential calculation, development and utilization potential calculation and geothermal resource comprehensive potential calculation are carried out, and development and utilization comprehensive potential calculation is combined with ecological red line distribution to delimit four areas of development priority, development encouraging, development postponing and development limiting. The geothermal resource development and utilization potentials of different regions are evaluated based on geothermal geological conditions, geothermal resource conditions and development and utilization requirements, finally, the large and middle potential regions are superposed through a spatial comprehensive analysis method, and a geothermal resource target region for further exploration is preferably selected from the large and middle potential regions. The invention provides a set of multi-element semi-quantitative geothermal exploration target region optimization theory and method.

The invention discloses a method and device for determining the mineral content of a shale oil reservoir. The method comprises the steps that natural gamma-ray spectrum logging data and lithologic density logging data of a target reservoir are obtained; based on the natural gamma-ray spectrum logging data and the lithologic density logging data, obtaining the volume content of a natural gamma-ray response component, natural gamma-ray spectrum logging skeleton data and lithologic density logging skeleton data of the target reservoir; based on the volume content of the natural gamma response component, correcting the lithologic density logging visual skeleton data and the natural gamma-ray spectrum logging visual skeleton data, and based on the corrected lithologic density logging visual skeleton data and the natural gamma-ray spectrum logging visual skeleton data, obtaining the volume content of the unnatural gamma response component of the target reservoir; and obtaining the mineral content of the target reservoir according to the volume content of the non-natural gamma component and the volume content of the natural gamma response component of the target reservoir. The method can be used for universally and effectively evaluating the mineral content of the shale oil reservoir.

The invention discloses a quantitative evaluation method for microbial residual coal mining and settlement reduction effects, and relates to the technical field of mining area resource mining and ecological control. The quantitative evaluation method for the microbial residual coal mining and subsidence reduction effects comprises the following steps: acquiring gas extraction data and ground surface subsidence data of a target goaf region within a set time period after microbial treatment; respectively inputting into a pre-trained time sequence analysis model, and extracting gas extraction time sequence characteristics and ground surface settlement time sequence characteristics of the target goaf region; analyzing a residual coal heat release conversion index and a ground surface settlement control index, and analyzing a collaborative evaluation index of the target goaf region; based on the collaborative evaluation index, the microbial residual coal mining and settlement reduction treatment effect grade of the target goaf region in the set time period is judged, an automatic and objective microbial residual coal mining and settlement reduction effect judgment system is formed by constructing the time sequence characteristics and the evaluation index, and the evaluation accuracy and the application reliability are improved.

The invention belongs to the field of geological development, and particularly relates to a deep shale gas geological development unit fine division method. The sedimentary ancient landform is recovered by integrating multi-source data, and multi-level unit division is performed in combination with multiple analysis methods. On the basis of restoration of sedimentary ancient landforms, ancient landform features are reconstructed through an impression method, and a basis is provided for division of first-level geological development units; on the basis of the first-level unit, the analytic hierarchy process is used for further detailed division, and a second-level geological development unit is depicted more finely in combination with methods such as clustering analysis; compared with the prior art, the method has the advantages that the heterogeneity in the reservoir of the target development unit can be comprehensively described, the non-linear relationship among multiple parameters is ensured to be embodied, and the scientificity of development unit division and reservoir evaluation is improved.

The invention relates to the technical field of drilling, in particular to a preparation method of composite lubricating particles for drilling fluid and the drilling fluid, the drilling fluid is formed by compounding a multi-defect-state g-C3N4-MoS2 heterostructure and nano bentonite, g-C3N4 is prepared through a urea-ammonium thiocyanate eutectic supramolecular self-assembly and gradient calcination technology, and the composite lubricating particles are prepared through a composite lubricating agent. Introducing an N vacancy by adopting plasma treatment; moS2 is subjected to oriented epitaxial growth on the surface of g-C3N4-MoS2 through a microwave-assisted hydrothermal method; the nano bentonite is obtained by high-pressure homogenization and supercritical CO2 stripping. After the drilling fluid is subjected to multi-stage dispersion, experiments find that the friction coefficient is as low as 0.43 and is reduced by 52% compared with that of conventional drilling fluid, the abrasion loss is reduced by 97% or above, the friction resistance in the drilling process can be remarkably reduced, the service life of a drill bit can be prolonged, and the drilling fluid is particularly suitable for ultra-deep well drilling operation of shale gas, deep sea oil gas and the like.

The invention discloses a method and device for drawing a carbonatite sedimentary facies diagram based on ternary coupling. The method comprises the following steps: determining a water depth environment based on a regional structure effect, a basin position, a substrate characteristic and a climate condition, and establishing a research region concept deposition mode; selecting a typical well, dividing a three-level sequence in the typical well according to earthquake, logging and core data, and further dividing a mapping unit; for each sequence, establishing a relationship between the ternary coupling of the water depth background, the sea level cycle and the paleo-geographic position and the sedimentary hydrodynamic condition and the stratum thickness, analyzing the thickness change of the single well stratum in the sequence, and reversely deducing the sedimentary hydrodynamic condition based on the relationship in combination with the water depth background, the sea level cycle and the paleo-geographic position; and determining a single-well facies under the guidance of the concept sedimentary mode, fitting, matching and correcting the single-well facies and hydrodynamic conditions, and drawing a sedimentary facies diagram of the drawing unit in combination with the regional structure trend. The method can draw a reasonable and accurate regional sedimentary facies diagram for a complex oil field group.

The invention provides a shale oil reservoir rock pyrolysis geochemical correction method and device based on stratum element data. The correction method comprises the steps that geological element data and rock pyrolysis geochemical data of a drilled well and a well to be corrected in a target area are acquired; calculating corresponding paleoenvironment data through the geological element data, and determining a sedimentary environment corresponding to the drilled well and the well to be corrected; a drilled well with the same sedimentary environment as the well to be corrected is selected, and the mapping relation between the organic matter contents at different temperatures in rock pyrolysis geochemistry of the drilled well is calculated; and calculating the organic matter content data of the to-be-corrected well according to the determined mapping relation and the rock pyrolysis geochemical organic matter content data of the to-be-corrected well, thereby completing data correction. According to the method, the adverse effect of the oil-based / synthetic-based drilling fluid on the rock pyrolysis geochemical data is eliminated, the precision and reliability of the data in the shale oil reservoir evaluation process are improved, and the method is of great significance to optimization of exploration and development of shale oil resources.

The invention belongs to the field of petroleum and natural gas geological exploration, and particularly relates to a method for predicting the scale of a sedimentary system. The method comprises the steps that a mathematical model with the gravel diameter changing along with the carrying distance is obtained from a modern sedimentary system, and the method for predicting distribution of the coarse-grain river fan and alluvial fan sedimentary system is formed by comparing and verifying the mathematical model with underground drilling core data. The method provided by the invention can quantitatively describe the change rule of the diameter of the sediment in the source-to-sink process of the coarse grain deposition system, so that the research on the distribution of the deposition system is changed from qualitative to quantitative; the mathematical model provided by the invention has good reliability and applicability.

The invention discloses a method for intensively developing a kerogen-rich shale oil reservoir by using a kerogen residual carbon resource, and relates to the technical field of unconventional oil and gas development. According to the method, water and oxygen-containing gas are injected into the shale oil reservoir rich in kerogen after electric heating in-situ exploitation, hydrogen and heat are generated by utilizing residual carbon enriched in the shale oil reservoir rich in kerogen, and kerogen at a large well spacing is further developed by utilizing the generated hydrogen and heat. According to the method, residual heat and residual carbon in the reservoir after in-situ development are electrically heated, the kerogen-rich shale oil reservoir after in-situ exploitation can be further developed without additional energy, the oil yield is increased, meanwhile, energy is saved, and the method is a novel green, low-carbon, safe and efficient unconventional oil reservoir development technology.

The invention discloses an organic-matter-rich carbonate rock unconventional natural gas exploration potential evaluation method and device, and aims to solve the geological characteristics that an organic-matter-rich carbonate rock integrates a source and a reservoir and has dual attributes of a shale gas reservoir and a conventional natural gas reservoir. The organic-matter-rich carbonate rock unconventional natural gas exploration evaluation and favorable area selection method is of great significance in promoting the organic-matter-rich carbonate rock unconventional natural gas to achieve exploration breakthrough and commercial development.

The invention discloses an ore dressing device and method based on ultraviolet irradiation. The ore dressing device comprises a processor and an ore conveying device, and the ore conveying device is used for conveying ore; ultraviolet light emitted by the ultraviolet light source irradiates the ore on the ore conveying device; the image acquisition device is arranged above the ore conveying device and is used for acquiring ore pictures under ultraviolet irradiation and transmitting picture information to the processor; the ore separation device is located at the tail end of the ore conveying device, the ore deviates from an original free parabolic path under the action of the ore separation device, and the ore separation device is connected with the processor and is controlled by the processor to be opened or closed; and the at least two material receiving devices are positioned below the tail end of the ore conveying device and are used for receiving the separated ore materials and tailings.

The invention relates to the technical field of exploration and development of petroleum and natural gas geological resources, and provides a method for quantitatively evaluating oil and gas accumulation in a deep concave area. The method comprises the following steps: according to a deep concave area oil and gas accumulation source reservoir combination matching principle, dividing deep concave area oil and gas accumulation dimensions into spatial combination and quantitative evaluation; three evaluation parameters of a reservoir in the deep concave area and three evaluation parameters of hydrocarbon source rocks in the deep concave area are screened out; obtaining values of three sub-indexes in the comprehensive evaluation index of the reservoir in the deep concave area and values of three sub-indexes in the comprehensive evaluation index of the hydrocarbon source rock in the deep concave area; respectively setting three corresponding space combination influence indexes; and processing to obtain a deep concave area oil and gas reservoir formation quantitative evaluation index, and performing deep concave area oil and gas reservoir formation quantitative evaluation of source reservoir combination matching according to the deep concave area oil and gas reservoir formation quantitative evaluation index. According to the method, the oil and gas accumulation potential of the deep concave area can be rapidly and quantitatively evaluated, the working efficiency is greatly improved, and the research cost is saved.

The invention discloses a molecular geochemical method for distinguishing shallow lake and semi-deep lacustrine facies high-quality hydrocarbon source rocks. The method comprises the following steps: establishing a 2-methylhopane index for indicating cyanobacteria contribution in hydrocarbon source rock and a 4-methylstane index for indicating algae contribution; evaluating the contribution of cyanobacteria and algae to shallow lacustrine facies and semi-deep lacustrine facies hydrocarbon source rocks by using a 2-methylhopane index and a 4-methylstane index; and a high-quality hydrocarbon source rock developmental facies belt and strata series with great contribution of cyanobacteria and algae are disclosed. According to the method, shallow lake and semi-deep lacustrine facies high-quality hydrocarbon source rocks can be quickly distinguished, the development mechanism and the distribution rule of the high-quality lacustrine facies hydrocarbon source rocks are disclosed, and help is provided for next oil-gas exploration deployment and decision making.

A system and a method for determining hydrocarbon production from multiple subterranean formations. Different nanotag tracers are sequentially injected into subterranean production zones fluidly coupled to a wellbore extending from a surface of the Earth through the subterranean production zones. The respective nanotag tracers are injected into a respective subterranean production zone. The different nanotag tracers and production fluids contained within the subterranean production zones are produced through the wellbore to the surface. A turbidity of the production fluids containing the different nanotag tracers is determined at the surface. A quantity of each of the one or more different nanotag tracers from each of the subterranean production zones in the production fluids is determined. Based on the turbidity of the production fluids and the quantity of the different nanotag tracers, a total oil production rate from the subterranean production zones is determined.

The invention discloses a method for predicting the radon exhalation rate of an ore body under a multi-factor coupling condition. The method comprises the following steps: collecting a rock sample in a mining area and processing the rock sample into a standard sample; measuring the porosity and the radium content of the sample; judging whether the porosity and the radium content are the same or not; and calculating the radon exhalation rate by utilizing a plurality of equation prediction models based on parameters such as temperature, water content, porosity and radium content. The radon exhalation rate prediction method comprehensively considers the coupling effect of multiple factors such as temperature, moisture content, porosity and radium content, overcomes the defects of a single-factor model, realizes more accurate prediction and effective prevention and control of radon exhalation behaviors of a mine, has good practicability, economical efficiency and popularization value, and is suitable for popularization and application. And powerful technical support is provided for mine radiation protection and safety production.

The application discloses a natural gas hydrate reservoir formation age analysis method, device and system, relates to the technical field of marine natural gas hydrate exploration, and comprises the following steps: collecting marine sediment samples in a natural gas hydrate drilling core column; performing a photoelectric age test on the marine sediment samples; establishing an age-depth model of the natural gas hydrate samples according to the obtained photoelectric age and sediment depth of the marine sediment samples; calculating the sedimentation time of the natural gas hydrate reservoir according to the age-depth model of the natural gas hydrate drilling, and further determining the formation age of the natural gas hydrate. The method can accurately determine the formation age of the natural gas hydrate, avoids the interference caused by the uncertainty of the natural gas hydrate reservoir forming time, and lays a geological exploration foundation for further revealing the natural gas hydrate reservoir forming mechanism.

The present invention relates to the technical field of mine ecological restoration and carbon reserve estimation, and in particular to a method and system for estimating carbon reserves in ecosystems in coal mining subsidence areas. The method comprises the following steps: S1, dividing the coal mining subsidence area according to land use type, and determining the scope and area of ​​each land use type; S2, dividing the coal mining subsidence area according to spatial state, and forming a land use grid table with a unique code for each land use type; S3, obtaining initial carbon density parameters corresponding to the land use type, calculating the effect of surface subsidence on the carbon density parameters of each sub-area of ​​the coal mining subsidence area, and performing differentiated corrections; S4, calculating the total carbon reserve at different subsidence stages, analyzing the carbon reserve, carbon sequestration, and spatial distribution of each land use type, and comprehensively analyzing the temporal variation characteristics of carbon reserves. The present invention combines land use and subsidence state to analyze carbon density changes, thereby achieving an assessment of the spatiotemporal evolution characteristics of carbon reserves in coal mining subsidence areas.

The present application relates to the technical field of standard sample, in particular to a lithium ore component analysis series standard sample and a preparation method thereof, the chemical component composition and content range of the standard sample are as follows: Li2O: 0.80~6.2%; Na2O: 0.2~4.0%; K2O: 0.4~4.4%; Rb2O: 0.05~0.7%; Cs2O: 0.02~0.3%; SiO2: 49~69%; Al2O3: 14~19%; TiO2: 0.004~0.05%; Fe2O3: 0.3~1.3%; P2O5: 0.1~1.1%; BeO: 0.01~0.05%; CaO: 0.5~7%; MgO: 0.1~0.6%; MnO: 0.04~0.2%; S: 0.005~3%; Ta2O5: 0.01~0.07%; Nb2O5: 0.003~0.02%; F: 0.04~2.2%; ignition loss: 2.0~14%. The lithium ore standard sample prepared by the present application has many fixed values, and the linear relationship of main components is good, and the problem of poor uniformity caused by the segregation of characteristic elements is avoided, the needs of different users, different instruments, different analysis methods can be met, and the lithium ore standard sample can be widely applied to the analysis and quality monitoring of lithium ore.

The invention relates to the technical field of standard samples, in particular to a lithium ore component analysis series standard sample and a preparation method of the lithium ore component analysis series standard sample. 0.2% to 4.0% of Na2O; 0.4 to 4.4 percent of K2O; rb2O: 0.05 to 0.7% of the total weight of the raw materials; 0.02% to 0.3% of Cs2O; 49 to 69 percent of SiO2; 14 to 19 percent of Al2O3; 0.004 to 0.05 percent of TiO2 (titanium dioxide); 0.3% to 1.3% of Fe2O3; 0.1% to 1.1% of P2O5; 0.01 to 0.05 percent of BeO; 0.5 to 7 percent of CaO; 0.1% to 0.6% of MgO; the content of MnO is 0.04 to 0.2 percent; 0.005 to 3 percent of S; 0.01% to 0.07% of Ta2O5; 0.003% to 0.02% of Nb2O5: (2); 0.04 to 2.2 percent of F; and the ignition loss is 2.0-14%. The lithium ore standard sample prepared by the method has many fixed value components and good main component linear relationship, avoids the problem of poor uniformity caused by easy segregation of characteristic elements, can meet the requirements of different users, different instruments and equipment and different analysis methods, and can be widely applied to analysis test and quality monitoring of lithium ore.

The evaluation method for structural fractures in continental shale oil reservoirs based on lithofacies constraints belongs to the field of petroleum geology and includes the following steps: (1) classifying the lithofacies types of continental shale in the study area; (2) based on the lithofacies type classification in step (1), extracting characteristic parameters affecting the development of structural fractures: continental shale brittleness index I, rock structure index S, and rock mechanical layer thickness H; (3) analyzing the sensitivity of different characteristic parameters in step (2) to the intensity response of structural fracture development; (4) analyzing the combination patterns of brittleness index, rock structure index, and rock mechanical layer thickness index of different lithofacies; (5) establishing a quantitative evaluation index for structural fractures in continental shale oil reservoirs based on lithofacies, and calculating the fracture development index F of different lithofacies. j This invention can be applied to the evaluation of structural fractures in continental shale oil reservoirs, providing technical support for the rational development of continental shale oil reservoirs in my country.

The invention provides a coal bed gas enrichment main control factor evaluation method, which relates to the field of geology, and comprises the following steps: collecting and sorting eight coal reservoir parameters including burial depth, reservoir temperature, reservoir pressure, Ro, vitrinite volume fraction, ash content yield and coal bed thickness and gas content data; the influence of each coal reservoir parameter on the gas content enrichment degree is quantitatively evaluated by adopting three methods of correlation analysis, random forest importance sorting and grey correlation analysis, and the evaluation result is normalized. On the basis, reasonable weights are dynamically given to all the methods through an entropy weight method, the total score of all the coal reservoir parameters is calculated, comprehensive sorting is conducted, and therefore quantitative evaluation of the coal bed gas enrichment main control factors is achieved.

The invention discloses a hot dry rock geothermal resource mining method, device and equipment and a storage medium. The method comprises the steps that parameter monitoring is conducted on multiple sets of geothermal exploitation and irrigation wells which are arranged in a target exploitation area in advance, a first exploitation and irrigation well which is in geothermal resource exploitation currently in the multiple sets of geothermal exploitation and irrigation wells is determined, and first exploitation and irrigation parameters corresponding to the first exploitation and irrigation well are determined; according to the first mining and irrigation parameters, the mining and irrigation well switching score used for switching mining and irrigation wells is determined; according to a preset switching threshold value range and the mining and recharging well switching score, determining a mining and recharging well switching scheme for switching the first mining and recharging well, and according to the mining and recharging well switching scheme, switching the first mining and recharging well which is currently exploiting geothermal resources to other mining and recharging wells in multiple groups of geothermal mining and recharging wells, intelligent switching and heat storage balanced development of well groups are achieved, continuity of geothermal energy production is guaranteed, the service life of geothermal resources is prolonged, and an economical and feasible technical path is provided for large-scale development of hot dry rock resources.

A quench oil may be excellent in thermal stability and may be capable of retaining the brightness for a prolonged period of time. Such a quench oil may contain a base oil containing a mineral oil (A), the mineral oil (A) having a 40° C. kinematic viscosity of 100 to 600 mm2 / s and a sulfur content of 0.10 to 0.20% by mass, the base oil having a content of the mineral oil (A) of more than 0.5% by mass, based on the total amount of the base oil.

The present invention provides an evaluation method for the enrichment degree of free hydrocarbons in continental shale oil, the evaluation method comprising the following steps: (1) clarifying the logging response characteristics of the free hydrocarbon-rich layer section, and selecting sensitive parameters for distinguishing free hydrocarbons from solid organic matter; (2) using the layer section data without free hydrocarbons or with low free hydrocarbon content to establish the change trend line of the sensitive parameters in the formation without free hydrocarbons or with low free hydrocarbon content; (3) using the layer section data with high free hydrocarbon content and low free hydrocarbon content to establish the change trend line of the sensitive parameters with the free hydrocarbon content; (4) using the difference between the change trend lines established in step (2) and step (3) respectively, to judge the relatively enriched layer section of free hydrocarbons in the formation. The evaluation method is highly accurate, convenient and quick, makes up for the shortcomings of the traditional evaluation method, and does not exaggerate or miss the real free hydrocarbon-rich layer section.

This invention provides a method for predicting vertical sweet spots in high-silica shale, comprising the following steps: S1, collecting shale core samples and obtaining measured experimental data and well logging data of the shale; wherein the measured experimental data of the shale includes measured TOC, NMR porosity, and relative content of silica minerals; S2, establishing the relationship between measured TOC, NMR porosity, and relative content of silica minerals, and determining the lower limits of relative content of silica minerals, TOC, and NMR porosity in the gas-producing section; S3, establishing a calculation model for the relative content of silica minerals in well logging; S4, determining the sweet spot section of the shale; S5, verifying the accuracy of the sweet spot section of the shale. This invention uses the relative content of silica minerals as the key parameter, which is simple and clear; the relative content of silica minerals is also the most important brittle mineral in shale. The higher the relative content of silica minerals, the better the brittleness of the shale, and the more conducive it is to fracturing. Therefore, the high silica content section is also the engineering sweet spot section. This method takes into account the prediction of both geological and engineering sweet spots.

The invention belongs to the technical field of oil-gas exploration and development, and relates to an ancient landform restoration method and system based on multivariate correction. The ancient landform is subjected to multivariate correction from six aspects of stratigraphic dip correction, denudation thickness recovery, structural trend correction, syngenetic fault correction, compaction thickness correction and ancient water depth recovery, and the ancient landform is recovered with high precision.

The invention provides a coal rock component calculation method and device. The method comprises the following steps: acquiring a coal rock sample to be analyzed; measuring the sample through an X-ray fluorescence spectrophotometer, and determining the elemental composition and content of the coal rock; performing element and mineral correlation analysis according to the coal rock sedimentary environment, and determining the occurrence characteristics of each element in the inorganic mineral components of the coal rock; and based on the occurrence characteristics of the elements in the inorganic mineral components of the coal rock, performing mineral inversion calculation to obtain the coal rock components. By utilizing the scheme of the invention, the requirements of field production on real-time analysis and evaluation of coal rock can be met.

A method for enhancing the production of hydrocarbons such as oil from a wellbore extending into a hydrocarbon reservoir. The method includes identifying a fissure within the hydrocarbon reservoir that is in fluid communication with the wellbore and injecting calcium brine solution and liquid carbon dioxide into the well bore so that the calcium brine solution may react with the carbon dioxide to precipitate calcite and substantially prevent fluid flow through the fissure. The method may enable selected fissures to be sealed thereby enhancing the overall productivity of the well. Other applications of the calcite precipitation method are also disclosed.