冀东油田南堡滩海地区油气层损害机理与油气层保护方法研究及应用

Study and Application of Damage Mechanism and Protection Method of reservoir in Nanpu Shallow Beach Sea Area is one of the key research projects of Jidong Oilfield Company of PetroChina Company Limited from 2007 to 2008. Located at Nanpu Sag in Huanghua Depression of Bohaiwan Basin, Nanpu Shallow Beach Sea Area with 1000km2 exploration area posseses three sets, shallow Minghuazhen Formation and Guantao Formation of Upper Tertiary, middle-deep Dongying Formation of Lower Tertiary, deep Ordovician, of oil bearing series, according to the achievement of the connecting 3D seismic structure interpretation and the structural geological comprehensive research. Its main reservoir types include Upper Tertiary structural reservoir, Lower Tertiary structural and lithological-structural reservoir, and Ordovician ancient buried hill reservoir. How to protect reservoir, complete well and lift high efficiently is the key to realize high and stable yield of the oil wells during drilling, completing well, testing and repairing well. It is important for reservoir protecting during drilling that directly relate to efficient exploration. Therefore, beginning with basic characteristics and sensitive analysis of reservoir, study of reservoir damage machinism and analysis of reservoir damage potential factor are emphasized when prediction analysis about three-pressure profiles is carried out. The study both of physical and chemical properties and of the strata of the technology of borehole stabilization and reservoir protecting are outstanding. As the conclusions follow: （1）Based on the laboratory experiment about basalt cores, prediction of three- pressure profiles about 30 wells on No.1 and No.2 structure is practiced. The laws of plane pressure distribution are analyzed. （2）According to the analyses about reservoir feature data and about sensitivity evaluation to damage factor in Nanpu oil field, the scheme of reservoir protecting to the sand reservoir of Guantao Formation and the first section of Dongying Formation is put forward. （3）On basis of the analyses on lithological characteristics, mineral compositions, clay minerals, electrical behavior features, physical and chemical properties of basalt of Guantao formation in No.1 and No.2 structure, instability mechanism of basalt sidewall and technical countermeasures are obtained. （4）Aiming at the characteristics of Ordovician dissolution-pore fracture type carbonate reservoir, the scheme of the reservoir protecting to Ordovician is put forward. Creative study of the film forming and sealing and low invasion reservoir protection drilling fluid are successful. In summary, through the study of reservoir heterogeneity and sensitivity, a set of technology and schemes of reservoir protecting is put forward, which is adaptive during drilling the target bed in the research area and establishes the base for efficient exploration. Significant effect has showed in its application in Nanpu oil field.

Magnetohydrodynamic equilibrium of plasma ball lightning

Thin foil observations using transmission electron microscopy reveal that the density of dislocations within the band is extremely high and the tangled arrangement of dislocations tends to align along the length of the shear band. The grains in the band were also elongated along the shear band and clearly exhibited a crystallographic nature.

Near-diffraction-limited, 35.4 W laser-diode end-pumped Nd:YVO4 slab laser operating at 1342 nm

A diode stack end-pumped Nd:YVO4 slab laser at 1342 nm with near-diffraction-limited beam quality by using a hybrid resonator was presented. At a pump power of 139.5 W, laser power of 35.4 W was obtained with a conversion efficiency of 25.4% of the laser diode to laser output. The beam quality M-2 factors were measured to be 1.2 in the unstable direction and 1.3 in the stable direction at the output power of 29 W. (C) 2009 Optical Society of America

Dynamic readout of subdiffraction-limited pit arrays with a silver superlens

Recent theoretical and experimental results suggested that the silver superlens could be constructed through controlling silver thin film thickness and preparation conditions, and applied in subdiffraction-limited optical imaging and optical lithography. In this work, we report another significant application of silver superlens-ultrahigh density optical data storage. With the silver superlens the subdiffraction-limited pit arrays on an optical disk are dynamically read out and the carrier-to-noise ratio can reach 25 dB for the thin film thickness of 46 nm. The readout laser power and readout velocity have little effect on the carrier-to-noise ratio. Additionally, in our experiment the silver thin film thickness needs to be controlled in the range from 20 to 80 nm.

Elevated ability to compete for limited food resources by 'all-fish' growth hormone transgenic common carp Cyprinus carpio

Food consumption, number of movements and feeding hierarchy of juvenile transgenic common carp Cyprinus carpio and their size-matched non-transgenic conspecifics were measured under conditions of limited food supply. Transgenic fish exhibited 73 center dot 3% more movements as well as a higher feeding order, and consumed 1 center dot 86 times as many food pellets as their non-transgenic counterparts. After the 10 day experiment, transgenic C. carpio had still not realized their higher growth potential, which may be partly explained by the higher frequency of movements of transgenics and the 'sneaky' feeding strategy used by the non-transgenics. The results indicate that these transgenic fish possess an elevated ability to compete for limited food resources, which could be advantageous after an escape into the wild. It may be that other factors in the natural environment (i.e. predation risk and food distribution), however, would offset this advantage. Thus, these results need to be assessed with caution.

Intrinsically limited critical temperatures of highly doped Ga1-xMnxAs thin films

Ga1-xMnxAs films with exceptionally high saturation magnetizations of approximate to 100 emu/cm(3) corresponding to effective Mn concentrations of x(eff)approximate to 0.10 still have a Curie temperature T-C smaller than 195 K contradicting mean-field predictions. The analysis of the critical exponent beta of the remnant magnetization-beta = 0.407(5)-in the framework of the models for disordered/amorphous ferromagnets suggests that this limit on T-C is intrinsic and due to the short range of the ferromagnetic interactions resulting from the small mean-free path of the holes. This result questions the perspective of room-temperature ferromagnetism in highly doped GaMnAs.

Holographic fabricated photonic-crystal distributed-feedback quantum cascade laser with near-diffraction-limited beam quality

We demonstrate the fabrication and characterization of photonic-crystal distributed-feedback quantum cascade laser emitting at 4.7 mu m. The tilted rectangular-lattice PCDFB structure was defined using a multi-exposure of two-beam holographic lithography. The devices exhibit the near-diffraction-limited beam emission with the full width at half maximum of the far-field divergence angles about 4.5 degrees and 2.5 degrees for stripe widths of 55 mu m and 95 mu m, respectively. Single-mode emission with a side mode suppression ratio of approximate to 20 dB is achieved in the temperature range (80-210 K). The single-facet output power is above 1 W for a 95 mu m x 2.5 mm laser bar at 85 K in pulsed operation. (C) 2009 Optical Society of America

Space-charge-limited currents in GaN Schottky diodes

Unusual dark current voltage (I-V) characteristics were observed in GaN Schottky diodes. I-V characteristics of the GaN Schottky diodes were measured down to the magnitude of 10(-14) A. Although these Schottky diodes were clearly rectifying, their I-V characteristics were non-ideal which can be judged from the non-linearity in the semi-logarithmic plots. Careful analysis of the forward bias I-V characteristics on log-log scale indicates space-charge-limited current (SCLC) conduction dominates the current transport in these GaN Schottky diodes. The concentration of the deep trapping centers was estimated to be higher than 10(15) cm(-3). In the deep level transient spectra (DLTS) measurements for the GaN Schottky diodes, deep defect levels around 0.20 eV below the bottom of the conduction band were identified, which may act as the trapping centers. The concentration of the deep centers obtained from the DLTS data is about 5 x 10(15) cm(-3). SCLC measurements may be used to probe the properties of deep levels in wide bandgap GaN-AlGaN compound semiconductors, as is the case with insulators in the presence of trapping centers. (c) 2005 Elsevier Ltd. All rights reserved.

Phonon-limited mobility in two-dimensional semiconductors with spin-orbit coupling

The authors demonstrate that the Rashba spin-orbit interaction in low-dimensional semiconductors can enhance or reduce the electron-phonon scattering rate by as much as 25%. The underlying mechanism is that the electron-phonon scattering phase space for the upper (lower) Rashba band is significantly enhanced (suppressed) by the spin-orbit interaction. While the scattering time decreases for the upper level, the mobility of the level increases due to an additional term in the electron velocity. (C) 2007 American Institute of Physics.