3D Physical Simulation Research Articles

Fire-flooding technologies in post-steam-injected heavy oil reservoirs

Abstract The mechanism and problems associated with development engineering of fire-flooding in post-steam-injected heavy oil reservoirs was studied using 1D & 3D physical simulation experiments and reservoir numerical simulation. The temperature of combustion zone decreased and high-temperature zone enlarged because there existed secondary water formed during steam injection, which could absorb and carry heat towards producers out of the combustion front during fire flooding, but high saturation of water in layers caused by secondary water had less influence on the quantity of fuel deposit and air consumption. In the process of 3D fire flooding experiment, air override was observed during the combustion front moving forward and resulted in a coke zone in the bottom of the layer, and the ultimate recovery factor reached 65% on fact that the remaining oil saturation within the coke zone was no more than 20%. The flooding model, well pattern, well spacing, and air injection rate were optimized according to the specific property and the existed well pattern in the post-steam-injected heavy oil reservoir, and the key techniques of ignition, lifting, and anticorrosion was also selected at the same time. The pilot of fire flooding in the H1 block in the Xinjiang Oilfield was carried out from 2009 based on these research works, and now begins to show better performance.

Global Order and Self-Organization in the Escherichia Coli Cell Wall

The ability of bacteria to grow into specific shapes depends on the accurate self-organization of the cell wall growth machinery. Absent a global roadmap, these enzymes must rely on local cues to guide the location and orientation of new material inserted into the peptidoglycan (PG) network. I will discuss our recent experimental and computational efforts in understanding the strategy used by Escherichia coli cells to grow into a rod shape. By combining 3D microscopy, particle tracking and physical simulations, we show that helical insertion of PG material guided by the actin homolog MreB leads to constant radius elongation and a robust global ordering of the glycan strands in a helical pattern relative to the cell long axis.

Evolutionary acquisition of behavior to build structural objects by virtual creatures

One of our purposes is to develop virtual creatures which can acquire behaviors such as building structural objects in a 3D physical simulation. In this article, we show the influences of behavior on structural objects which are built by virtual creatures. Many creatures can change their environment for the better by building structural objects, for example, spiders’ nests. In the field of artificial life, there are many studies of virtual creatures which change their bodies and behavior to suit their environments. In contrast, there are few studies about virtual creatures which build structural objects. As for natural creatures, virtual creatures need a physical interaction between their body and their environment. Therefore, our purpose is to develop a framework for the autonomous acquisition of behaviors which build structural objects in a 3D physical simulation. In order to do this, we first studied the evolutionary acquisition of behavior for building structural objects, e.g., a nest for predation, by the simple behavior of throwing blocks. As a result, we show the possibility that virtual creatures can acquire building behavior evolutionarily.

Parameter set and data sampling strategy for accurate yet efficient statistical MOSFET compact model extraction

Abstract This paper presents an effective statistical compact modelling strategy that can precisely capture a statistical set of MOSFET characteristics into industrial strength statistical compact models. 3D simulation of large statistical sample of microscopically different devices is required for statistical compact model extraction when studying the impact of variability in next CMOS technology generations on circuit and system design. For a particular nominal device design the statistical 3D physical simulations needs two orders of magnitude more CPU time compared to conventional TCAD simulations. A data sampling strategy is presented to reduce the number of bias points in simulated device characteristics used as extraction targets for statistical compact model parameter extraction. We show that for a well balanced set of statistical compact model parameters carefully chosen small number of strategic bias points in the simulated I–V characteristics of each microscopically different transistor is sufficient to capture accurately the statistical device behaviour. The corresponding increase in the RMS error is below 1% compared to results from comprehensive bias point set. The impact of the slight reduction of the compact model accuracy on the accuracy of statistical circuit simulation has also been investigated.

A scalable substrate network for compact modelling of deep trench insulated HBT

3D Physical simulation has been used to analyse the impact of substrate parasitic elements on HBT electrical characteristics. A geometry scalable SPICE model is proposed and the resulting electrical simulation results are compared with physical simulation results. All lumped elements can be calculated directly from layout and technological data. The model is implemented in the scalable HBT compact model HICUM Level 0. A comparison with respect to measurements from a 0.25 μm BiCMOS technology with several HBT emitter areas shows an improvement of the simulation results.