Implementation of multilayer perceptron(MLP)and radial basis function(RBF)neural networks to predict solution gas-oil ratio of crude oil systems

Exact determination of pressure-volume-temperature(PVT)properties of the reservoir oils is necessary for reservoir calculations,reservoir performance prediction,and the design of optimal production conditions.The objective of this study is to develop intelligent and reliable models based on multilayer perceptron(MLP)and radial basis function(RBF)neural networks for estimating the solution gas–oil ratio as a function of bubble point pressure,reservoir temperature,oil gravity(API),and gas specific gravity.These models were developed and tested using a total of 710 experimental data sets representing the samples of crude oil from various geographical locations around the world.Performance of the developed MLP and RBF models were evaluated and investigated against a number of well-known empirical correlations using statistical and graphical error analyses.The results indicated that the proposed models outperform the considered empirical correlations,providing a strong agreement between predicted and experimental values,However,the developed RBF exhibited higher accuracy and efficiency compared to the proposed MLP model.

Effects of Temperature and Catalyst to Oil Weight Ratio on the Catalytic Conversion of Heavy Oil to Propylene Using ZSM-5 and USY Catalysts

It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC （fluid catalytic cracking）. The effects of temperature and C/O ratio （catalyst to oil weight ratio） on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil （VGO） was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas （LPG）, repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC （hydrogen transfer coefficient） and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/A1203 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.

Low gas-liquid ratio foam flooding for conventional heavy oil

The recovery of heavy oil by water flooding is 10% lower than that of conventional crude oil, so enhanced oil recovery （EOR） is of great significance for heavy oil. In this paper, foam flooding with a gas-liquid ratio （GLR） of 0.2：1 for the Zhuangxi heavy oil （325 mPa.s at 55 ℃） was performed on cores, sand packs and plate model. In sand pack tests, polymer enhanced foam flooding increased oil recovery by 39.8%, which was 11.4% higher than that for alkali/surfactant/polymer （ASP） flooding under the same conditions. Polymer enhanced foam flooding in plate models shows that the low GLR foam flooding increased oil recovery by about 30%, even when the extended water flooding was finished at 90% water cut. Moreover, it was discovered by microscopy that foam was more stable in heavy oil than in light oil. These results confirm that low GLR foam flooding is a promising technology for displacing conventional heavy oil.

Evaluation of diagnostic ratios of medium and serious weathered oils from five different oil sources

Laboratory experiments were conducted to simulate oil weathering process, a medium to long term weathering process for 210-d, using samples collected from five different oil resources. Based on relative deviation and repeatability limit analysis about indexes of these samples, the results show there had been significant changes in diagnostic ratios among the initial and weathered samples of different oils during this process. Changes of selected n-alkane diagnostic ratios of all oil samples displayed more obviously than diagnostic ratios of terpanes,steranes and PAHs in this process. Almost all selected diagnostic ratios of terpanes, steranes and PAHs can be efficiently used in tracking sources of hydrocarbon pollution, differentiating from the n-alkane diagnostic ratios.In these efficient diagnostic ratios, only four ratios maintained good stability in the weathering processes and are more suitable because their relative deviation（RSD） are lower than 5%.

Effects of Use and Re-Use of Selected Vegetable Oils on the Proximate, Minerals, Mineral Ratios and Mineral Safety Index of Raw and Fried Plantain Chips: Note I

Raw and fried plantain chips obtained from the use and re-use of olive, refined palm olein and coconut oils were investigated for the proximate, mineral compositions, computed mineral ratios and the mineral safety index using standard analytical methods. For the selected oils (both use and re-use): first and second re-use and the fresh plantain chips (unprocessed plantain chips;UPC) had the following range results: proximate composition (%) (moisture: 8.20 - 12.3, crude protein: 9.70 - 8.60, fat: 7.40 - 12.9, fibre: 3.50 - 4.90, ash: 2.80 - 3.80 and carbohydrates: 63.5 - 64.8), % energy contributions (PEC: 63.4 - 70.8, PEF: 20.2 - 28.6, PEP: 8.03 - 9.66, UEDP: 4.49 - 5.08). The mineral composition (mg/100g) of the samples had the following greater than 80.0: Ca, Mg, K and P;Fe, Cu, Mn and Zn recorded values ranging between 1.00 and 4.00;Co, Se and Ni had their concentrations between 0.00 and 0.0363 whereas Pb and Cd recorded levels lower than 0.0006. In the mineral ratios, only K/(Ca + Mg) values fell within the acceptable ideal range. No MSI aberration was observed for the minerals from all the samples obtained from the various oils. The chi-square analysis showed that on parameter wise comparisons, there were no significant differences among the levels as treated based on the various oils except gross energy, Mg, K, P, Ca/P, Fe/Pb and K/Co. Also on pairwise comparison from linear correlation and regression, all these parameters were significantly different at r = 0.01 between the unprocessed and fried plantain samples: proximate, percentage energy distribution, mineral and mineral ratios. Generally, the first (day) frying showed fairly high nutrient concentration than the first and second re-use oils products. Therefore, for optimum nutrient preservation from fried plantain chips re-use of oil for frying should be sparingly allowed. However, olive showed highest level of nutrients in terms of proximate and mineral compositions.

Crude oil cracking in deep reservoirs:A review of the controlling factors and estimation methods

The natural cracking of crude oils in deep reservoirs has gained great interest due to continuously increasing depth of petroleum exploration and exploitation.Complex oil compositions and surroundings as well as complicated geological evolutions make oil cracking in nature much more complex than industrial pyrolysis.So far,numerous studies,focused on this topic,have made considerable progress although there still exist some drawbacks.However,a comprehensive review on crude oil cracking is yet to be conducted.This article systematically reviews the controlling factors of oil cracking from six aspects,namely,oil compositions,temperature and time,pressure,water,minerals and solid organic matter.We compare previous experimental and modelling results and present new field cases.In the following,we evaluate the prevailing estimation methods for the extent of oil cracking,and elucidate other factors that may interfere with the application of these estimation methods.This review will be helpful for further investigations of crude oil cracking and provides a guide for estimation of the cracking extent of crude oils.

基于改进Fisher Ratio的RBF网络在油浸变压器故障诊断中的应用

针对Fisher Ratio不能使网络结构得到最大优化这一缺点,提出应用改进Fisher Ratio方法选择RBF网络隐层节点数及径向基函数中心,并采用改进的Fisher比算法完成基于DGA的油浸变压器故障诊断。结果表明,该方法能极大地简化网络结构,提高了分类能力和收敛精度。与改良电协研法相比,具有较好的故障识别效果。

Investigation into co-pyrolysis characteristics of oil shale and coal

Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry （TG）, given a heating rate of 30 ℃/min to a final tem- perature of 900 ℃. Investigations on pyrolysis of mixing coal and oil shale in different proportions were carried out, indicating that the main scope of weight loss corresponding to hydrocarbon oil and gas release was between 350 and 550 ℃. At higher temperatures, significant weight loss was attributed to coke decomposition. Characteristic pyrolysis parameters of blends from oil shale and the high ranked XZ coal varied with the blending ratio, but oil shale dominated the process. At the same blending propor- tions, highly volatile medium and low ranked coal of low moisture and ash content reacted well during pyrolysis and could easily create synergies with oil shale. Medium and high ranked coal with high mois- ture content played a negative role in co-pyrolysis.

Geochemical analysis of mixed oil in the Ordovician reservoir of the Halahatang Depression,Tarim Basin,China

In this study,12 crude oil samples were collected and analyzed from the Ordovician reservoir in the Halahatang Depression,Tarim Basin,China.Although the density of oil samples varies considerably,based on saturated hydrocarbon gas chromatographic(GC),saturated and aromatic hydrocarbon gas chromatographic-mass spectrometric(GC/MS) and stable carbon isotopic composition analyses,all the samples are interpreted to represent a single oil population with similar characteristics in a source bed or a source kitchen,organic facies and even in oil charge history.The co-existence of a full suite of n-alkanes and acyclic isoprenoids with UCM and 25-norhopanes in the crude oil samples indicates mixing of biodegraded oil with fresher non-biodegraded oil in the Ordovician reservoir.Moreover,according to the conversion diagram of double filling ratios for subsurface mixed crude oils,biodegraded/non-biodegraded oil ratios were determined as in the range from 58/42 to 4/96.Based on oil density and oil mix ratio,the oils can be divided into two groups:Group 1,with specific density>0.88(g/cm3) and oil mix ratio>1,occurring in the north of the Upper Ordovician Lianglitage and Sangtamu Formation pinchout lines,and Group 2,with specific density<0.88(g/cm3) and oil mix ratio<1,occurring in the south of the pinchout lines.Obviously,Group 2 oils with low densities and being dominated by non-biodegraded oils are better than Group 1 oils with respect to quality.It is suggested that more attention should be paid to the area in the south of the Upper Ordovician Lianglitage and Sangtamu Formation pinchout lines for further exploration.

Research into polymer injection timing for Bohai heavy oil reservoirs

Polymer flooding has been proven to effectively improve oil recovery in the Bohai Oil Field. However, due to high oil viscosity and significant formation heterogeneity, it is necessary to further improve the displacement effectiveness of polymer flooding in heavy oil reservoirs in the service life of offshore platforms. In this paper, the effects of the water/oil mobility ratio in heavy oil reservoirs and the dimensionless oil productivity index on polymer flooding effectiveness were studied utilizing rel- ative permeability curves. The results showed that when the water saturation was less than the value, where the water/oil mobility ratio was equal to 1, polymer flooding could effectively control the increase of fractional water flow, which meant that the upper limit of water/oil ratio suitable for polymer flooding should be the value when the water/oil mobility ratio was equal to 1. Mean while, by injecting a certain volume of water to create water channels in the reservoir, the polymer flooding would be the most effective in improving sweep efficiency, and lower the fractional flow of water to the value corresponding to △Jmax. Considering the service life of the platform and the polymer mobility control capacity, the best polymer injection timing for heavy oil reservoirs was optimized. It has been tested for reservoirs with crude oil viscosity of 123 and 70 mPa s, the optimum polymer flooding effec- tiveness could be obtained when the polymer floods were initiated at the time when the fractional flow of water were 10 % and 25 %, respectively. The injection timing range for polymer flooding was also theoretically analyzed for the Bohai Oil Field utilizing which provided methods for effectiveness. relative permeability curves, improving polymer flooding

Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

In order to recognize the distribution of dispersed remaining oil,reservoirs should be described in more detail and quantitatively to establish refined and sophisticated 3D quantified reservoir model which can reflect the detailed variation in the reservoir and its structure.The key point of sophistication and quantification of reservoir characterization is to describe the geo-metry of interwell sandbodies and to estimate their reservoir parameters.

Crude oil mobility and its controlling factors in tight sand reservoirs in northern Songliao Basin, East China

Taking tight oil in Gaotaizi and Fuyu oil layers of the Upper Cretaceous Qingshankou Formation in northern Songliao Basin as an example, based on analyses of nuclear magnetic resonance and high pressure mercury injection, experiment methods of supercritical carbon dioxide displacement and extraction are firstly employed to quantify crude oil mobility in tight sand reservoirs with different lithologies and oil contents. The results show that, under the conditions of simulating the Cretaceous Qingshankou Formation in the northern Songliao Basin at a temperature of 76-89 °C and a pressure of 35-42 MPa, the lower limit of the porosity of the movable oil is4.4%, and the lower limit of the permeability is 0.015′10-3 mm2. The lower limit of the average pore throat radius is 21 nm. On this basis,a classification standard for three types of tight sand reservoirs is proposed. Type I reservoirs are characterized by the movable fluid saturation larger than 40%, the movable oil ratio(ratio of movable oil to total oil) greater than 30% and the starting pressure gradient in the range of 0.3-0.6 MPa/m; Type II reservoirs are characterized by the movable fluid saturation in the range of 10%–40%, the movable oil ratio in the range of 5%–30% and the starting pressure gradient in the range of 0.6–1.0 MPa/m; Type III reservoirs are characterized by the movable fluid saturation less than 10% in general, the movable oil ratio less than 5%, and the starting pressure gradient greater than1.0 MPa/m. The fluid mobility in tight sand reservoirs is mainly affected by diagenesis and sedimentary environment. Reservoirs with depth lower than 2000 m are dominated by type I reservoir, whereas those with greater depth are dominated by type I and II reservoirs.Reservoirs in inner delta-front facies are dominated by type I reservoir, whereas those in outer delta-front facies and shore-shallow lacustrine facies are dominated by type II and III reservoirs.

Degradation of crude oil by indigenous microorganisms supplemented with nutrients

Different kinds of mineral nutrients(NO_3-N, NH_4-N and PO_4-P) were applied in the simulated oil-polluted seawater for enhancing oil biodegradation in the N/P ratio 10∶1 and 20:1 Although indigenous microorganisms have the ability to degrade oil, adding nutrients accelerated biodegradation rates significantly. For the group amended with NO_3-N and PO_4-P in the ratio 10∶1, the reaction rate coefficient was 4 times higher than the natural biodegradation. Chemical and microbiological analysis showed that the optimal N/P ratio in the system is 10∶1, and microorganisms tend to utilize nitrate rather than ammonium as N source.

The damping model for sea waves covered by oil films of a finite thickness

In combination with a wave action balance equation, a damping model for sea waves covered by oil films of a finite thickness is proposed. The damping model is not only related to the physical parameters of the oil film, but also related to environment parameters. Meanwhile, the parametric analyses have been also conducted to understand the sensitivity of the damping model to these parameters. And numerical simulations demonstrate that a kinematic viscosity, a surface/interfacial elasticity, a thickness, and a fractional filling factor cause more significant effects on a damping ratio than the other physical parameters of the oil film. From the simulation it is also found that the influences induced by a wind speed and a wind direction are also remarkable. On the other hand, for a thick emulsified oil film, the damping effect on the radar signal induced by the reduction of an effective dielectric constant should also be taken into account. The simulated results are compared with the damping ratio evaluated by the 15 ENVISAT ASAR images acquired during the Gulf of Mexico oil spill accident.

Complicated water-oil distribution and water out in high permeable fracture and cave system,but relatively good oil-bearing condition presents in low permeable ones

According to drilling core analysis and a lot of.field information,it was proved that the current reservoir range above oil-water contact detected by observation wells,was no more a complete pure oil bearing zone with exception of water cone,but a complicated oil-water mixed zone.The oil,satura-tion in the fracture system varied greatly.The large fractures with width of over 100μm were al-most water flushed,the middle fractures between 50-100μm were water encroachment zone and the small fractures less than 50μm were still in a good oil-bearing condition.

Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

As stated above,the ultimate recovery of conventional oil in our country is estimated to be 33.6%,i.e,about 66.4%of the oil reserves cannot be recovered by water injection and may only be targeted for tertiary oil recovery or for other ty pes.of new technologics.A screening of 82 major oifields developed by water injection and an analysis of their potential showed that application of tertiary recovery technique such as polymer flooding,surfactant flooding and gas miseible flooding will inerease the oil recovery by 12.4%.The total recoverable reserve increment cor-responds to 56%of the current remaining recover-able reserves.This means that the recoverable r'eserves in OUr country can increase by more than one half by a fully tapping of the potential.Therefore,the development of tertiary recovery technology will be an important strategic measure in China's petroleum industry.

Development of High Viscous Oil in Sandstone Reserviors During the High Water Cut Stage，Gudao Oilfield

The oi!bearing area of Gudao Oilfield covers 80.9 square kilometers.with 373 million tons of oil in place.It is a large drape anticlinal.Neogene Gu-dao Formation is main oil-beraing reservoir devel-oped with dip gentle from 30'to 1°30'in general.The main oil-bearing sequences can be divided into 6 sand groups and 34 layers in detail.in which the Ng°-Ng°sand groups are the main payzones in which oil in place accounts for 97.2%of the total.

Establishment and application of an intelligent treating method for oil spill identification

In the identifying process of an oil spill accident, manual integral and artificial visual comparison are commonly used at present to determine the oil spill sources, these methods are time-consuming and easily affected by human factors. Therefore, it is difficult to achieve the purpose of rapid identification of an oil spill accident. In this paper, an intelligent method of automatic recognition, integration and calculation of diagnostic ratio of Gas Chromatography-Mass Spectrometer （GC/MS） spectrum are established. Firstly, four hundreds of samples collected around the world were analyzed using a standard method and Retention time locking technology （RTL） was applied to reduce the change of retention time of GC/MS spectrum. Secondly, the automatic identification, integration of n-alkanes, biomarker compounds, polycyclic aromatic hydrocarbons and calculation of the diagnostic ratios were realized by MATLAB software. Finally, a database of oil fingerprints were established and applied successfully in a spill oil accident. Based on the new method and database, we could acquire the diagnostic ratios of an oil sample and find out the suspected oil within a few minutes. This method and database can improve the efficiency in spilled oil identification.

Screening and Domestication of High Effective Microorganism Used in Oil Containing Wastewater Remediation

According to the characteristics of oil containing wastewater, four strains of microorganism, named TA-11, TA-17, HA-9, HD-1, were picked out from the oil contaminated soil and activated sludge of biochemical treatment system of an asphalt plant wastewater in Panjin. They can degrade oil and CODCr in oil containing wastewater. The research result showed that each strain of microorganisms can remove oil and CODCr in oil containing wastewater effectively when the pH value was 7.0, the temperature was 30 degree Celsius, the rotation speed was 140r/min and the inoculation amount was 10%. Especially the highest removal ratio of CODCr was 68% after growth of 64 hours. The removal ratio of CODCr in oil containing wastewater of mixed bacilli was much higher than that of unitary bacilli, and mixing a certain amount of domestic sewage with the oil containing wastewater will also improve the removal rate of CODCr.