摘要 :
Lithological trap identification in thin sand and thick shale layers is still a challenge for hydrocarbon exploration. Based on the high-resolution sequence stratigraphy theory and the establishment of high-resolution sequence str...
展开
Lithological trap identification in thin sand and thick shale layers is still a challenge for hydrocarbon exploration. Based on the high-resolution sequence stratigraphy theory and the establishment of high-resolution sequence stratigraphy framework with seismic-well tie, the dynamic deposition process of braided delta sands on late Cretaceous Yogou formation has been analyzed on 62 wells in passive rifting Termit basin with multi-stages depressions and reversals. (1) Six kinds of sedimentary microfacies and three major reservoir sands with multi-stages vertical stacking and lateral migration are in late Cretaceous; (2) Based on accommodation space/Sediments supply change and depositional progress, sedimentary facies distribution evolution has been done according to sands thickness statistics of sedimentary micro-facies, and narrow-time seismic attributes and slices analysis, multi-sources braided delta depositional model has been concluded; (3) Based on source rock and caprock evaluation, with reservoir sands distribution and faults impact on Yogou formation of Termit basin, four types of traps, including structure-lithology, Structure-strata, stratigraphic and lithology are concluded. Traps influencing factors, i.e., structure geometry, sands distribution, paleotopography, stratigraphy cycling, sand/shale lateral connection, reservoir quality and so on, have different impacts on these traps, and different lithologic-stratigraphy traps have different exploration risks. Structure geometry and sands distribution are very important for the structure-lithology traps; structure geometry and paleotopography are the key factors in Structure-strata traps. Sands distribution and reservoir quality can be focused on lithology traps. Moreover, paleotopography and sand/shale lateral connection are significant on stratigraphic traps. Therefore, different hydrocarbon accumulation types of lithological traps have been established.
收起
摘要 :
Complicated fluvial sands correlation and braided river models are still challenges for heterogeneous anisotropic reservoir evaluation for petroleum development in oilfields. Based on high-resolution sequence stratigraphy and sedi...
展开
Complicated fluvial sands correlation and braided river models are still challenges for heterogeneous anisotropic reservoir evaluation for petroleum development in oilfields. Based on high-resolution sequence stratigraphy and sedimentology, core observation, and the analysis of logging and seismic data, high-resolution sequence stratigraphy framework of Paleogene Yabus formation of Palogue Oilfield, South Sudan is established, and sedimentary characteristics of braided rivers are analyzed, (1) In braided river deposits, channel bars are usually pro-gradating seawards and going thicker upwards. And braided channels are retro-gradating landwards and going thinner upwards. Both of them can be subdivided into channel (bar) trunks and channels (bar) flanks, showing vertical stacking and lateral migration; (3) As the A/S (Accommodation space/sediments supply) increasing upwards, braided river sands are shifting frequently as a reciprocating migration in Yabus V/VI, and they are more stable as the A/S decreasing upwards as a vertical aggradation in Yabus VII/VIII; (4) With 77 wells sedimentary microfacies identification, sand thickness and sand/bed ratio distribution, sedimentary facies distribution of all members and zones are analyzed. According to the A/S change, three braided river models are concluded, including isolated channel type (high A/S period), crossed channels type (medium A/S period), and superposed channels type (low A/S period).
收起
摘要 :
Laminal damage is a main type of damage in the adhesive bonded joint, and it often occurs in the interface layer of the joint. So, it is necessary to analyze the mechanical action of the interface layer. However, because the thick...
展开
Laminal damage is a main type of damage in the adhesive bonded joint, and it often occurs in the interface layer of the joint. So, it is necessary to analyze the mechanical action of the interface layer. However, because the thickness of the interface layer is very small, it is difficult to simulate the interface layer by regular finite element method or boundary element method, and it is also difficult to simulate the process of laminal damage. To aim at this situation, we use the cohesive interface element with the thickness of zero to simulate the interface layer to get the rule of laminal damage, and contrast with experimental result to validate the validity of the method. By contrasting with experimental result, we find the result in the simulation is identical with the result in the experiment. So, the method of using the cohesive interface element to simulate the interface layer is effective.
收起
摘要 :
Laminal damage is a main type of damage in the adhesive bonded joint, and it often occurs in the interface layer of the joint. So, it is necessary to analyze the mechanical action of the interface layer. However, because the thick...
展开
Laminal damage is a main type of damage in the adhesive bonded joint, and it often occurs in the interface layer of the joint. So, it is necessary to analyze the mechanical action of the interface layer. However, because the thickness of the interface layer is very small, it is difficult to simulate the interface layer by regular finite element method or boundary element method, and it is also difficult to simulate the process of laminal damage. To aim at this situation, we use the cohesive interface element with the thickness of zero to simulate the interface layer to get the rule of laminal damage, and contrast with experimental result to validate the validity of the method. By contrasting with experimental result, we find the result in the simulation is identical with the result in the experiment. So, the method of using the cohesive interface element to simulate the interface layer is effective.
收起
摘要 :
The singulation of the die on BGA substrates is of much significance to the subsequent packaging processes, and the importance is thus attached to it. The saw blade made from the metal and diamond is extensively used in this proce...
展开
The singulation of the die on BGA substrates is of much significance to the subsequent packaging processes, and the importance is thus attached to it. The saw blade made from the metal and diamond is extensively used in this process and it has great influences on the cutting quality of the dies. It is known that the blade edge wears during the singulation process, causing a taper-shape on both sides of the edge, and this will copy its shape to the bottom of the substrate leaving a small lip called "lip effect" that leads to chipping and the loss of the die size. To alleviate this problem, it is necessary to optimize the blade matrix materials and the diamond concentration to maintain a flat blade edge for a long time.
收起
摘要 :
In order to complete the space-ground coordination tasks during the autonomous control of the spacecraft, the ground-based measurement and control system needs to simulate the autonomous control process to predict the orbit of the...
展开
In order to complete the space-ground coordination tasks during the autonomous control of the spacecraft, the ground-based measurement and control system needs to simulate the autonomous control process to predict the orbit of the spacecraft and guide the station to track it. In general missions, the spacecraft's orbit forecast ephemeris is used to calculate the epoch and azimuth angle corresponding to a fixed elevation angle under the station coordinate system, and use this as the guidance information. For autonomously controlled spacecraft, the ground system cannot accurately simulate the motion process of the spacecraft and predict the orbit. When the predicted orbit deviation is large, the use of the above method may cause the equipment to fail to capture. In order to solve the problem, a spacecraft station guidance calculation method based on combined deviation orbit prediction is proposed. When the station uses the guidance data calculated by this method to capture, it only needs to wait at the theoretical waiting point, and the waiting time is a certain interval. The method makes the station operation simple and easy to judge the tracking situation.
收起
摘要 :
According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the auth...
展开
According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the author established contact finite element models of single-tooth pair in ANSYS. The calculated value of contact pressure of the single tooth contact finite element model and the calculated value of contact pressure which given by the point-contact Hertz theory were compared to verify the effectiveness of the contact finite element method. Several groups of parameters were calculated and the results showed that the use of reasonable asymmetric design can effectively reduce the max surface contact pressure and the max tooth root bending stress.
收起
摘要 :
According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the auth...
展开
According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the author established contact finite element models of single-tooth pair in ANSYS. The calculated value of contact pressure of the single tooth contact finite element model and the calculated value of contact pressure which given by the point-contact Hertz theory were compared to verify the effectiveness of the contact finite element method. Several groups of parameters were calculated and the results showed that the use of reasonable asymmetric design can effectively reduce the max surface contact pressure and the max tooth root bending stress.
收起
摘要 :
A calculative model for parallel shaft split torque transmission system is presented, the model includes stiffness of shaft supporting, time-varying stiffness, damping, gear eccentric error errors, bearing eccentric errors, gear t...
展开
A calculative model for parallel shaft split torque transmission system is presented, the model includes stiffness of shaft supporting, time-varying stiffness, damping, gear eccentric error errors, bearing eccentric errors, gear tooth thickness error, assembly error. Dynamic analytic model is built using the theory of equivalent mesh error and Newton method. The model was solved by variable step size forth/fifth-order Runge-Kutta method. The result shown all error affect load sharing in different way, one error deduced sharply can not improve load sharing obviously.
收起
摘要 :
A calculative model for parallel shaft split torque transmission system is presented, the model includes stiffness of shaft supporting, time-varying stiffness, damping, gear eccentric error errors, bearing eccentric errors, gear t...
展开
A calculative model for parallel shaft split torque transmission system is presented, the model includes stiffness of shaft supporting, time-varying stiffness, damping, gear eccentric error errors, bearing eccentric errors, gear tooth thickness error, assembly error. Dynamic analytic model is built using the theory of equivalent mesh error and Newton method. The model was solved by variable step size forth/fifth-order Runge-Kutta method. The result shown all error affect load sharing in different way, one error deduced sharply can not improve load sharing obviously.
收起
原文获取