The present work develops a computer-aided algorithm to transform gasoline bulk property into molecular composition. We pre-defined 166 representative gasoline molecules according to the compositional characteristics. Simulated annealing method was used to find a molecular distribution that has bulk property very closed to the measured data. The accuracy of the model is verified by using a set of FCC gasoline data. The relative error of predicted and measure key property is lower than 2% and the overall relative error is lower than 5%. The predicted PIONA composition is in good agreement with experimental results, indicating that the obtained compositional information is in consisted with the actual composition.
Targeting on hydrodesulphurization, hydrodenitrification and hydrodemetallization from inferior VGO, hydrotreating experiments were conducted to investigate the effect of various hydrotreating conditions on the quality of the hydro-products. Meanwhile, variation of the components and its corresponding change of macroscopic properties were also analyzed on the basis of three types of inferior VGO. The rates of hydrodesulfurization, hydrodenitrogenation and hydrodemetallization were improved with the increase of reaction temperature. Compared with raw oil, hydrogenated oil has a low 95% point distillation temperature and density, and the content of sulfur, nitrogen and metal in the produced oil is greatly reduced.
The adsorption/desorption and diffusion properties of methylpentane and-n-hexane on ZSM-5，5Ａzeolites were investigated by using the intelligent gravimetric analyzer (IGA-003). The results indicated that ZSM-5 zeolite has higher adsorption capacity for methylpentane which is almost 26 times bigger than that of 5A zeolite. Moreover, adsorption capacity of n-hexane on a ZSM-5 is lower than that of a 5A, but the single-cycle desorbed amount of n-hexane on a ZSM-5 is similar to that of 5A due to the easy release properties. Unfortunately, the adsorption heat and diffusion resistance of methyl pentane on the studied ZSM-5 remain high result in the high desorption temperature. Therefore, the excellent naphtha adsorbent maybe prepared by optimizing the mass transfer quality of ZSM-5. The results can provide important basic data for the optimal selection of the excellent adsorbent for naphtha.
A multi-directional analysis for the application of oil shale residue in the field of chemical industry and environment and the heap abandonment present situation of the oil shale residue is proposed. It is found that there are six limitations in recycling oil shale residue in the field of environment and chemical industry, which lead to the difficulty of proper and reasonable disposal of oil shale residue. The environmental pollution caused by oil shale residue is still serious. Based on the indepth discussion of the local limit, a new idea for disposing the oil shale residue is presented, which uses the oil shale residue to prepare bulk material of large social needed, and the preparation process is simple and the secondary energy consumption is less.
Aiming at the bad stability performance of normal foam in the Yan Chang No.6 oil field, a high stability gel foam system was developed and then evaluated in the aspect of stability and plugging. Through comparison and selection, now the system is made up of 0.4% FP388 foam agent, 0.3% AZ polymer, 0.3% T1&T2 crosslinker, and 0.3% CK2 foam stabilizer. The stability experiment of gel foam indicate that the half life of gel foam is 12 d and the viscosity of gel foam can stay at a high level, also remains stable in 30 d under 80 ℃ and 10 000 mg/L mineralization degree environmental conditions. The foam gel system has good injection and gel forming properties and can effectively seal medium high permeability reservoir.
The oil sands reserves in the Urho area of Xinjiang are relatively abundant. Therefore, it is necessary to analyze its composition and structure so as to provide references for the selection of industrial processing schemes for oil sand separation. In this paper, the composition and structure of oil sands are determined by means of instrumental analysis. The experimental results show that the oil content of oil sands is 6%~16%, the solid content is 82%~92% and the water content is between 0.5%~2.0%. The sum of the contents of carbon and hydrogen in the extracted bitumen oil is 91%, the sulfur content is low, and the oxygen content is relatively high, which is 7%. The mass fractions of saturated fraction, aromatic content, colloid content, asphaltene content are 40%,21%,27% and 12%, respectively. The solid phase of oil sand is mainly composed of clay and sand. The main compositions are SiO2 and Al2O3, and the average diameter of oil sand is 204 μm.
The volatilization characteristics of ClO2 solution were investigated using a self-made laboratory bubbling reactor. The effects of temperature, bubbling flow and concentration of ClO2 solution on the volatilization rate of ClO2 solution were studied. The results show that ClO'2s volatilization is enhanced with increasing of ClO2 solution concentration, bubbling flow and temperature. However, when the mass concentration of ClO2 in solution is very low, the temperature has little effect on the evaporation rate. The relationship between volatilization and concentration of ClO2 solution is linear. Based on the experiments, the correlation model of the concentration of ClO2 solution attenuation with time is established: c=c0e-kt, the correlation of the volatilization rate coefficient of ClO2 solution is also obtained: k=2.152 5×10-5θ+3.427 6×10-4Q-7.599 7×10-4. The model calculation is in good agreement with the experiment results, and can be used to calculate the volatilization rate of ClO2 solution in the bubble reactor.
The computational efficiency of the existing polymer flooding simulator is difficult to adapt to the large complex reservoir simulation of the meshing scale of more than one million nodes, which seriously restricts the decision speed of the reservoir development. Hence, we propose a new concise brinebased simulation method for polymer flooding in this study, which can not only significantly improve the speed of numerical simulation, but also can comprehensively consider the key mechanism of enhanced oil recovery by polymer flooding. The accuracy and applicability of the new method are demonstrated in three aspects: the comparison of the simulation results with the traditional polymer flooding, the significant effect of the void volume and the significant effect of the adsorption loss. The new method is used to simulate the polymer flooding in a large river heavy oil field with a large scale of nearly 5 million grid. It takes only 5.8 h to complete a single virtual development simulation, while the traditional simulator takes 518.4 h and the calculation efficiency is nearly 90 times under the same condition, which confirms the high efficiency and application value of the new method.
The development of low permeable reservoir by means of alternate water gas injection can not only enlarge the swept volume, supplement formation energy, but also effectively prevent gas channeling. However, the problem of plug in gas well often occurs during the construction. By simulating the distribution of internal pressure and temperature in the wellbore of the gas injection well, the cause of freezing and plugging is analyzed. The main reason is the long time shut in of the gas injection well, resulting in the formation of fluid flowing back to the frozen plugging section and the CO2 reaction in the wellbore to form a frozen plug. Therefore, the well test method is used to calculate the pressure change rule in the wellbore after closing the well, and the time of formation fluid to freeze plugging is obtained. The results show that the gas injection rate has great influence on the wellbore temperature field distribution. As the injection speed increases, the low temperature in the wellbore extends longer. The phase state of CO2 gas can change within 1 000 m of the wellbore, which causes low temperature and high pressure in the wellbore and makes hydrate easily. Finally the limit closure time of injection well is determined to be 25 d according to the law of oil and gas twophase seepage and the law of pressure change after well closure.
The concentration of ions in the three element composite flooding is higher, the radius of the suspended particles is larger, the emulsification of the crude oil is serious, and the O/W emulsion is formed, which contains the polymer and the surface active agent. So, the viscosity of the three element composite flooding is larger and the composition is more complex. The above reasons make it difficult for the three yuan produced liquid to achieve better separation effect by conventional sedimentation treatment when oil and water separation is carried out. Through indoor sedimentation experiment, the settlement effect of the three surfactant polymer flooding under the conditions of different settling time and settlement temperature is studied, and effect and technical limits after mixing of three yuan and polymer flooding system are clearly defined. The experimental results show that three yuan of produced liquid in the blending of polymer flooding produced liquid, helps to reduce the three yuan produced liquid mixed with polymer flooding produced liquid is helpful to reduce the oil-water separation difficulty. From the analysis of water quality of mixed wastewater, the mixed three yuan extraction liquid and the polymer flooding recovery solution can not only reduce the sewage the treatment difficulty, but also be more conducive to the stable operation of the existing three yuan oilfield produced water treatment process. The optimum mixing ratio of three yuan production fluid and polymer flooding production fluid is1∶3,and the optimum mixing settlement time limit is 8 h.
By means of logging response analysis, reservoir comprehensive analysis and analytic hierarchy process, the deposition of meandering river in the lower reaches of Minghua Zhen group in the two Zhuang oilfield is studied. The control and influence on residual oil for different levels of meandering river reservoir architecture for single river channel, point bar and the inner configuration unit of point bar are analyzed through log response analyses, reservoir analyses and arrangement analyses method based on the research of meandering river reservoir architecture at extra-high water cut development period.
On the basis of previous studies, the lithology, physical properties, electrical properties and oilbearing characteristics of Chang6 reservoir in this area are analyzed and studied. Further, the Chang 6 reservoirs in this area are divided into four types: pay bed (oilwater layer), waterproducing layer, mixed zone (mixed zone of pay bed and water producing) and dry layer. Then, the fluid identification standard for the Chang6 reservoirs of the target area is established based on the logging standardization. It is proved that the standard is effective by examples, which provides powerful technical support for identifying pay bed quickly and accurately in this area. The results of this study have important guiding significance.
According to the geological characteristics and data of LJ region, the prestack study is used as the main means to analyze the relationship between the dominant lithology and the mineral content, and to establish the lithology identification standard based on the basic data of LJ dense oil from core and log analysis. Based on the petrophysical analysis, the data of "two width and one height" are used to predict the dominant lithology, dolomite content, property and brittleness of lithology and dolomite in the same time. The seismic data of AVOZ anisotropic fracture are performed by means of the partial azimuthal offset seismic data. Finally, the results of lithological prediction and fracture prediction are combined together with the results of comprehensive geological study, and the results of geological research are integrated to point out the predominant dessert area and guide the exploration and deployment.
The actual denoising effect of wavelet denoising methed was studied through pipe flow test apparatus, which simulated the actual pipeline leakage condition. The reason why small leak was not easy to be found was explained from two expects through timefrequency analysis of the leakage signal attenuation process. And the disadvantages of the most commonly used wavelet de-noising method to deal with small leakage signal were also discussed. On this basis, a new threshold function was established to improve the signal reconstruction accuracy and the advantage was analyzed mathematically. Next, a blind source separation algorithm based on maximum signal-to-noise ratio (SNR) was proposed, which integrated wavelet transform with blind source separation. By separating the known structural signal, the applicability of this method was illustrated, and the practical denoising effect and industrial application value of the fusion algorithm were verified.
In twin hole drilling, traditional technology only allows achieving an initial depth in twin hole due to limitations imposed by tools, processes and technologies. At the same time, there are some drawbacks, such as having two wells in one hole, making another hole when reaming and poor cementing quality. All these conditions make it impossible to meet demands of some wells. To solve these problems, based on the analysis of the advantages and disadvantages of the existing technology, combing the technological difficulties and technical limitations, the key points such as surface pretilt, reaming, casing down, cementing and cementing, and two hole separation are optimized. Finally, a set of practical, safe and efficient single barrel and double well preoblique reaming technology is obtained.
The development of polymer flooding injection wells in X oilfield is based on the development method of up fill-up, which has many problems, such as the large amount of up-filled plugging works, and the subsequent contribution of water drive zones to production. Therefore, the study on the process of stratified injection technology for water & polymer in the same well is carried out. Through the design of the tube column in the upper layer of the injection well and the lower layer general water injection process, four key technologies involving large diameter washable well packer, polymer injection sliding sleeve switch, plugging sealing section and special connecting collar are studied. The water and the polymer are injected at the same time in the single well. The laboratory test and field test of the tool have obtained good experimental results. This technology provides technical support for the development of the up-fill stimulation on the polymer flooding blocks.
