There is abundant naphthenic crude oil in China National Offshore Oil Corp. (CNOOC), which can be utilized as the optimal stock to produce the lube base oil. Because the distillate oil has high acid number, it brings many negative effects to the production and the performance of the lube oil. Meanwhile, the naphthenic acid is a very important and valuable raw material that can be used in many areas of the industry processes and the daily life. At present, the way to decrease the acid number is alkali washing-electronic field refining, but there some disadvantages such as the emulsification formation of the oil and water, the generation of the sediment of alkali and serious pollution to environment. Due to various disadvantages present in the way of conventional deacidification the”green solvent”-ionic liquid and the way of hyrodeacidification were used as the alternative methods to remove the naphthenic acid from the distillate oil in this study.In this paper, the [bmim]OH was firstly selected as the deacidification agent from [bmim]BF4, [bmim]OH and [emim]OH. At the same time, the alcohol was chosen as the assistant agent by evaluating the assistant deacidification agent. In the experiment, the No. 2 vacuum cut of cnooc was our sample oil. The optimal operation conditions were obtained by the experiment of the factor influencing the deacidification effect. The result indicated that the removal rate is higher than 76% when the concentration of depickling solvents is 0.1g.ml-1. The ration of solvent to oil is 1:1, the depickling temperature is 40℃and the reaction time is 50min.On the basis of the deacidification experiment, the callback research was carried out as well. Mainly study the hydrolyzing callback and the acidification callback. The experiment indicated that acidification callback has the advantages of the high acid number, short reaction time. In hydrodeacidifiction research, RL-1 was the experimental catalyst and the experimental stock were the atmospheric cut 3 and the vacuum cut 3 distillate oil, the influential factors were decided in partial pressure of hydrogen of 3.2MPa and 6.4MPa, The experimental result show that hydrodeacidification has high deacidification rate, high yield and the hetero atoms can be removed by this way
Oil and gas Archive
Products Quarlity of the Atmospheric Distillation & Set-Up and Application of Yield Model for Predication
We’ve got the model for predication of the atmospheric products quarlity and yeild by sampling the production running data of Daqing Refinery & Chemical Company 3500000 tons/year Atmospheric Pressure Vacuum Distillation Production Unit and using SPSS maths statistic software to do linear regression on its data. We’ve tested for the equation and predominance of each model resulting that after being tested by production running data, the error of the models is acceptable. We’ve proved that the models we got have great epitaxy, and by using the models we ‘ve carried out the atmospheric products quarlity predication and the atmospheric products yield predication. We’ve successfully changed our working method from experience to quantitative index in both judging production parameters and assigning company’s production plans.
Study for Raising the Cementing Quality of the Adjustment Well in the Areas with High Permeability and Low Pressure
The Daqing Oil Field has gotten into the phase of the third redensification adjustment well exploitation. The area of the north of the oil field with high permeability and low pressure has been in the late exploitation period with high aquiferous quantity and high output. The aquiferous quantity of the high permeability layers of the old area’basic well web has been more than 95%. The stratum has been submerged heavily. The hole dypass within the layers was washed out for a long time. Its colloid was taken away and the penetration rate increased greatly . After cementing the well under the condition of the time-lapse sound wave and distinguishing density logging,the formation liquid can come into being the corrosive nature to the cement annulus so that it would reduce the limestone intensity and destroy the cementation quality of the second well cementation interface. How to raise the cementing quality of the adjustment well in the areas with high osmosis and low pressure under the condition of the time-lapse sound wave differencing density logging. It has already been an important subject about oil field exploitation.By studying the erosion and damage from the formation liquid to the cement annulus and the annularity space pressure gap and the influence from the drilling fluid performance to the stratum with high permeability and low pressure,it is summarized out a theory about that how the high permeability and low pressure layers affect the cementation quality. Through the method to guarantee high presses and the irrigation can achieve stabilizes and reduces the level the differential pressure; Using the eddy liquid well-washing technology can be possible to clean the wall of a well effectively the empty filter cake; Using the technology of cementing with outer-casing packer may reduce the damage of the annulus and the intrabed differential pressure to the cementation quality of the stratum with high permeability and low pressure; Using the passive self-excitation waterpower pulse vibration well cementation technology and the continual oscillating field producing in the annular cement mortar may improve the well cementation quality. Through the applied research,We have made the pretty good matching technique measures. Combining field-experiment with apply,it shows that the measures can effectively raise the cementing quality of the high permeability and low pressure formation.
The reasonable selection of drill bit plays a very important role in improving the drilling speed and reducing the drilling cost. In order to lay a foundation for solving the drilling engineering problems and promoting the development of Daqingzijing oil field, the rock drillability was investigated and the optimal selection of drill bit was made by means of the gray correlation analysis method.The drillabilities of rocks fed from different strata in Daqingzijing oil field were analyzed and researched. The extreme value of bit drillability was evaluated by using the data of well logging. The study results showed that the PDC bit was suitable to use in the strata, such as Sifangtai, Nen 5duan, Nen 2duan, Yaojiazu and Qing 2+3 shangduan. However, the roller bit was proper to use in the Nen1duan stratum.On this basis, the optimal selection of drill bit was made by taking the drilling cost as the evaluation objective, analyzing the application condition of bits and using the gray correlation analysis method. The study results showed that the roller bit was the most suitable to use in the strata under Qingshankou and the PDC bit was the most suitable to use in the strata over Qingshankou.
As the basic equipment of the exploitation of offshore oil, gas resources and the base of the work and living at the sea, an offshore platform is playing an increasingly important role in petroleum industries. Assessment-based on global offshore platform structure under fire hazard can help us to save much more steel material and construction cost by utilizing the structural interaction effect between members more effectively, and analyzing fire-resistance ability of steel platform. In order to investigate the total fire-resistance capability of platform structure, CII offshore platform is applied to carry out global structural response analysis under irregular wave and oil tank fire in this dissertation.The fire combustion analysis is precondition for global structure fire resistance research. Fire characteristic and the fire trait of offshore platform are illustrated, and the global structural temperature and response of offshore platform under fire are analyzed. Based on the burning characteristics of oil tank fires and the energy balance of heat feedback on the oil surface, a global model is built and the burning rate is calculated iteratively. Based on the Mudan model, the radiation model is developed for the steady burning oil tank. Based on energy conservation theory, the horizontal and vertical distributions of radiation around the burning tank are calculated. The temperature field of members subjected to fire is calculated by establishing the temperature calculation model of fire. The nonlinear stress-strain relation of steel along temperature is applied to the structural analysis.,and a transient calculation of finite element analyse platform is gotten out in order to get variable stresses and displacements under wave, temperature and wind loads. The temperature of members is rising because of fire, and the bearing capacity of structure descends obviously because of the drop of Young’s modulus and yield strength. Wave force in northeast is more destructive than wave force in southwest for CII offshore platform whose peg A is burning. Based on the obtained simulation results, it appears that this new method can provide an advantageous reference for users engaged in fire-resistance research of offshore platform.
The long chain n-alkane will precipitate in form of wax crystal at low temperature, to plug catheter and filter, which would disturb diesel engine system because of lack of diesel oil. It is necessary to take measures to decrease diesel oil solidification point, improve low-temperature flowing. Diesel cold flow improver is a kind of common diesel additives in diesel production. Wax alkane in diesel will precipitate by small crystal when cold flowing improvers are added to diesel, which keeps diesel oil flowing in low-temperature. It is convenience for storage, transportation and use. The researches to prepare cold flow improvers with better application effect are very significant.Firstly, we synthesized the diesel low-temperature flowing improver which rigid structure monomer copolymerized with, studied the impact of diesel cold filter plugging point with the changes of branched chain, polymerization reaction condition, rigid structure monomer’s quantity and monomers respectively, dicycropentadiene–maleic ester(amide)–styrene tripolymer can improve the diesel cold filter plugging point effectively, and amide is better than ester. The change of reaction condition leads to the change of main chain molecule weight, and acrylic ester is better than other monomers. Secondly, we designed and synthesized pentaerythritol ester, long chain alkyl amide and paratert–butyl benzamide, three kinds of small molecule wax crystal disperse assistant. The hybrid of paratert–butyl benzamide mixed with T1804C could decreased the cold filter plugging point of Shijiazhuang 0# diesel oil by 3℃to 9℃. Finally, we duplicate matched tripolymer with T1804B, studied the decreasing cold filter plugging point effect of mixture, the impact of additive quantity and the relationship between n-alkane in test diesel and cold filter plugging point. Mixture is better than single additive universally. The quantity of additive is determined by working curves of certain diesel and additive.
20ⅹ104 t/a IDW plant of DaQing Refinery and Chemical Company is the first plant which uses the IDW patent technology of America Chevron to produce high viscosity index, low pour point,high quality base oil in China .Since starting up in 1999,the yield of 5.0 cst heavy oil of 200SN is far different from the design value, and the yield is the benefit point of the plant.The thesis analyses the HDT reaction, the IDW reaction,the HDF reaction ,the property of the feeds, the property of product, finds out seven factors which affect each other ,plurality linear regresses the relative factors which affect 5.0 cst heavy oil yield by the log and the statistics analysis software SPSS, sets up mach model, seeks the method which quantitative optimizes operation parameters and forecasts product yield.By statistics test and practice test of the building model, according with production practice, changing operation parameters and optimizing operation, changing the former experience operation into quantitative guide operation and forecasting the production yield at the same time.
Finite Element Analysis of Large Vertical Oil Tank Based on Contact Simulation of the Interaction between Tank Bottom Plate and Foundation
With the rapid development of petrochemical industry and in the light of the increasingly importance of energy security, a great number of large-scale oil storage tanks have been built worldwide. The large unanchored oil storage tank is the key equipment of the national strategic oil storage reservoir. Any failure of these tanks will be a catastrophe. Therefore, it is very important to conduct research on the safety assessments of these tanks. In this thesis analysis on the strength and deformation of the 5×10~4m~3 oil tanks have been conducted by the finite element numerical simulation. Following are the main research contents and results.With the aid of ANSYS software, the 2D axisymmetric and 3D solid FEA (Finite Element Analysis) model of large vertical oil tank was constructed. Contact elements were used to simulate the interaction between tank bottom plate and its foundation. Several types of element such as Solid95, Solidl85, Plane183, Targe169, Conta172, Targe170 and Conta174 were adopted to build the model. With the help of APDL (ANSYS Parametric Design Language), the FEA model was of parametric function.In the 2D axisymmetric FEA, through intensive analysis on the case of tank dead load and hydrostatic pressure, the stress strength and its distribution at the tank parts were obtained. It was found that the maximum stress intensity appeared in the connection between tank bottom and inside of grand welded joint. The maximum hoop stress was located at the middle and lower part of the tank wall and the axial change of hoop stress was no longer simply proportional to the hydrostatic pressure. In the whole sand filling area, the amount of settlement of the foundation is basically the same. The largest settlement gradient took place in the edge area of concrete foundation, producing large radial and hoop stresses in the corresponding area of bottom plate.For the 3D finite element model which considered the combination of dead load, hydrostatic pressure and wind load, results showed that wind load has nearly no impact on the settlement of the foundation, but has considerable influence on the strength of the grand welded joint between tank wall and the edge of the tank bottom.
Extended reach well of Drilling technology has a good applied prospect in such a time that drilling technology highly developed. This paper gives the calculating formula for angle of hold angle section of wellbore curve through studying the optimized design of extended reach well’s wellbore trajectory. And based on the principle of determining the build point, it deducts the calculating formula for different shapes of built section, including circular profile and twin increase profile of constant curvature method in build up section, cycloid, catenary, amended catenary, quasi- catenary, lateral catenary and parabola of various curvature method. Using weighted coefficient estimation method, the optimist curve was found accord to the facts of length of borehole, length of build section, build rate and all kinds of friction and torque.
The failure law of different casings under different operating conditions are analyzed, the critical in-situ stress equations under different operating interior pressures and the chart of optimizing casings’ types are achieved by way of the establishment of nonlinear FEM(finite element model). With the increment of minimum in-situ stress and the decreasing of critical in-situ stress coefficient, the distribution of interior critical stress of casings is different, and the change law is that the irregular shape tend to be a constricted ellipse, the shape of external load due to salt formation inclines to ellipse with the decreasing of critical in-situ stress coefficient, which is contrary to the direction of maximum and minimum in-situ stress. To prepare the early task during production, the critical in-situ stress equations under different operating interior pressure can be used to estimate the corresponding field-application roughly. Furthermore, the types of casings under different non-uniform in-situ stress can be optimized according to the chart of optimizing casings’ types.The structure of the existed bulge offered by Zhongyuan Oil Field is optimized, and the results show that the radial expanding force offered by bulge can recover the failed casing, the sticking point is how much hydraulic pressure can hydraulic device on the ground afford. Based on the operation principle of bulge, nonlinear FEM to recover failed casing is built in this paper and the general results are: for the same kind of casing under the same operating interior pressure, the force of recovery increases regularly with the increment of thickness, especially for the thicker casing and the casing under higher operating interior pressure, the force of recovering is larger, and the requirement of bulge is more exigent. According to the data obtained in Zhongyuan Oil Field, ordinary casing can’t bear such extremely high non-uniform in-situ stress, so special casing must be developed to the production of oil and water wells which are situated in gypsum-salt rock.