Parallel numerical simulation for a super large-scale compositional reservoir

 A compositional reservoir simulation model with ten-million grids is successfully computed using parallel processing techniques. The load balance optimization principle for parallel calculation is developed, which improves the calculation speed and accuracy, and provides a reliable basis for the design of reservoir development plan. Taking M reservoir as an example, the parallel numerical simulation study of compositional model with ten million grids is carried out. When the number of computational nodes increases, message passing processes and data exchange take much time, the proportion time of solving equation is reduced. When the CPU number increases, the creation of Jacobian matrix process has the higher acceleration ratio, and the acceleration ratio of I/O process become lower. Therefore, the I/O process is the key to improve the acceleration ratio. Finally, we study the use of GPU and CPU parallel acceleration technology to increase the calculation speed. The results show that the technology is 2.4 ∼ 5.4 times faster than CPU parallel technology. The more grids there are, the better GPU acceleration effect it has. The technology of parallel numerical simulation for compositional model with ten-million grids presented in this paper has provided the foundation for fine simulation of complex reservoirs.Cited as: Lian, P., Ji, B., Duan, T., Zhao, H., Shang, X. Parallel numerical simulation for a super large-scale compositional reservoir. Advances in Geo-Energy Research, 2019, 3(4): 381-386, doi: 10.26804/ager.2019.04.0

Comparative Analyses by Sequencing of Transcriptomes during Skeletal Muscle Development between Pig Breeds Differing in Muscle Growth Rate and Fatness

Understanding the dynamics of muscle transcriptome during development and between breeds differing in muscle growth is necessary to uncover the complex mechanism underlying muscle development. Herein, we present the first transcriptome-wide longissimus dorsi muscle development research concerning Lantang (LT, obese) and Landrace (LR, lean) pig breeds during 10 time-points from 35 days-post-coitus (dpc) to 180 days-post-natum (dpn) using Solexa/Illumina's Genome Analyzer. The data demonstrated that myogenesis was almost completed before 77 dpc, but the muscle phenotypes were still changed from 77 dpc to 28 dpn. Comparative analysis of the two breeds suggested that myogenesis started earlier but progressed more slowly in LT than in LR, the stages ranging from 49 dpc to 77 dpc are critical for formation of different muscle phenotypes. 595 differentially expressed myogenesis genes were identified, and their roles in myogenesis were discussed. Furthermore, GSK3B, IKBKB, ACVR1, ITGA and STMN1 might contribute to later myogenesis and more muscle fibers in LR than LT. Some myogenesis inhibitors (ID1, ID2, CABIN1, MSTN, SMAD4, CTNNA1, NOTCH2, GPC3 and HMOX1) were higher expressed in LT than in LR, which might contribute to more slow muscle differentiation in LT than in LR. We also identified several genes which might contribute to intramuscular adipose differentiation. Most important, we further proposed a novel model in which MyoD and MEF2A controls the balance between intramuscular adipogenesis and myogenesis by regulating CEBP family; Myf5 and MEF2C are essential during the whole myogenesis process while MEF2D affects muscle growth and maturation. The MRFs and MEF2 families are also critical for the phenotypic differences between the two pig breeds. Overall, this study contributes to elucidating the mechanism underlying muscle development, which could provide valuable information for pig meat quality improvement

Load capacity of a new rope-climbing robot

Theoretical analysis and experimental research are carried out on the load capacity of one new kind rope-climbing robot, this robot could lift load along the rope depends on the friction between rope and wheel of the robot. The classic Euler formula is based on the assumption of constant friction coefficient, and this paper establishes a new load capacity model based on non-constant friction coefficient model, presents a method to measure the distribution of friction coefficient, and builds the experimental platform to conduct experimental research on the friction coefficient and load capacity. Experimental results show that the friction coefficient decreases with the increase of wrap angle; the new model fits the results better than Euler formula

Load capacity of a new rope-climbing robot

Theoretical analysis and experimental research are carried out on the load capacity of one new kind rope-climbing robot, this robot could lift load along the rope depends on the friction between rope and wheel of the robot. The classic Euler formula is based on the assumption of constant friction coefficient, and this paper establishes a new load capacity model based on non-constant friction coefficient model, presents a method to measure the distribution of friction coefficient, and builds the experimental platform to conduct experimental research on the friction coefficient and load capacity. Experimental results show that the friction coefficient decreases with the increase of wrap angle; the new model fits the results better than Euler formula

Updating and application for a reservoir geological model of deep-water turbidites: A case study of a 4D seismic survey from the PU Oilfield in Angola

During traditional updating processes of reservoir models, the final optimal modelis mainly selected referring to the historical matching results from individual drilling wells, as there is a lot of uncertainty in the distribution prediction of remaining oil crosswells. 4D seismic survey is one of the important modern methods for oil reservoir monitoring, and it has a strong advantage forguiding the distribution prediction of remaining oil cross wells. 4D seismic monitoring information is incorporated into conventional updating processes of geological models, to improve the updating accuracy of reservoir geological models. Fluid evolution information provided by 4D seismic surveys lends solid basis for developing an iterative update method with 4D seismic monitoring, geological modelling, and reservoir simulating.Results in this study suggests that ①4D seismic dynamic information can help improve the numerical modelling loops; ②4D seismic surveys can provide important evidence for the cross-well model parameter adjustment, which help promote the quantitative monitoring of remaining oil and improve the accuracy of reservoir model predictions. This method has a good application effect in deep-water turbidite reservoirs and has practical significance for the development of numerical modelling loops