Guo Y.Q.,Institute of Geomechanics |
Ma H.D.,CGG |
Ba J.,Petrochina |
Zhao H.B.,Eandd Research Institute |
And 3 more authors.
76th European Association of Geoscientists and Engineers Conference and Exhibition 2014: Experience the Energy - Incorporating SPE EUROPEC 2014 | Year: 2014
P-and S-wave velocities are measured on 65 sandstone samples of Daqing oilfield (northeast China) at ultrasonic frequencies. Base on the laboratory measurements, a new approach of EFSI (effective fluid sensitivity indicator) is proposed to evaluate the fluid sensitivity of rock physics parameters for identifying sandstone oil-reservoirs. In combination with the cross plot analysis, it is shown that the optimized parameters effectively discriminate pore fluid in reservoir rocks.
Liu C.,China University of Petroleum - Beijing |
Zhou G.,China University of Petroleum - Beijing |
Ma Y.,Institute of Geomechanics
Oil and Gas Journal | Year: 2011
The Qaidam basin is one of three main oil and gas basins in Northwestern China. A large number of geological surveys have indicated most Carboniferous rocks to be sedimentary rocks with medium thermal evolution and hydrocarbon generation potential. Carboniferous petroleum resources in place were calculated to be 4.5-5.3 billion bbl in the Qaidam basin. Its oil and gas resource richness is moderate compared with that of Carboniferous formations of other basins in the world. Through 2010, cumulative proved oil in place and recoverable reserves were 3.1 billion bbl and 750 million bbl, respectively, and cumulative proved gas in place and recoverable reserves were 10.2 tcf and 5.5 tcf, respectively. Qaidam production averaged 36,500 b/d of oil and 530 MMcfd of gas in 2010. Located in the southern part of the basin, the Geermu oil refinery has a capacity of 30,000 b/d.
Schlogel R.,University of Liège |
Torgoev I.,Institute of Geomechanics |
De Marneffe C.,University of Liège |
Havenith H.-B.,University of Liège
Earth Surface Processes and Landforms | Year: 2011
There is a strong possibility that environmental change (whether climate or land use) will be manifest as changes in the size-frequency distribution of landslides. Here, evidence is presented for this from western Kyrgyzstan, Central Asia. Remote sensing and spatial analysis have been applied to map mass movements in the central part of the Maily-Say Valley and to detect recent landslide activations. The evolution of landslide activity over the past 50years has been analysed on the basis of pre-existing landslide maps and new analyses of aerial photographs as well as Quickbird images. Five inventories were produced for the years 1962 (based on the existing map of 1962 and aerial photographs of 1962), 1984 (based on the existing map of 1977 and aerial photographs of 1984), 1996 (based on aerial photographs of 1996), 2002 (based on the existing map of 2003 and Quickbird imagery of 2002) and 2007 (based on Quickbird imagery of 2007). The geomorphologic features contained in the catalogues represent the landslide bodies observed from remote imagery of the corresponding year. Mapped landslides are generally considered as the result of a series of slope failure events. Size-frequency analyses applied to the five landslide inventories show that both the number and size of unstable slopes increased from 1962 (162 objects) to 2007 (208 objects) and the power-law exponent decreased over time. This changing power-law exponent may indicate that landslide-related hazards are increasing. This tendency is documented in more detail for two active landslide zones, one in the main valley and one located to the west of it. Landslide detection methods were used to assist the evolution of slope instabilities. Choosing appropriate thresholds, the image subtraction method based on normalized difference vegetation index (NDVI) allowed accurate detection of new sliding activation in these two zones. This confirmed the results of the more extensive survey that there is a systematic shift in power law exponents and size-frequency distributions for Central Asian landslides. © 2011 John Wiley & Sons, Ltd.
Sun D.-S.,Institute of Geomechanics |
Wang L.-J.,Institute of Geomechanics |
Zhao W.-H.,Institute of Geomechanics |
Wang H.-C.,Institute of Geomechanics
Geology in China | Year: 2010
For the purpose of reduction and prevention of coal and gas outburst disaster, the authors conducted measurement of in -situ stress and mechanical parameters of rocks, and studied geological structure and gas pressure. On such a basis, criteria were established for appropriate quantitative evaluation of the stability. The dangerous areas of coal and gas outburst were predicted regionally, and the results are consistent well with the situ situation. The regional and local prevention measures were put forward, which have been proved to be effective. All this suggests that the prediction of regional dangerous areas is important for the selection of prevention measures.
Zhao G.-L.,Institute of Geomechanics
Kuangwu Yanshi/ Journal of Mineralogy and Petrology | Year: 2012
The Tarim basin experienced tectonic change and environmental alteration from Cretaceous to Tertiary. Many researchers have done important research on the tectonics,petrology,sedimentary facies and sequence and achieved many result, but few people done any research about geochemistry of sandstone and mudstone from Cretaceous to Tertiary, especially the geochemistry background at the boundary between Cretaceous and Tertiary. After observation of rocks from three typical cross sections and drilling wells of Cretaceous and Tertiary in the Tarim basin, this paper studied the sedimentary source, tectonic background and paleogeography based on the data of main elements,trace elements and rare earth elements from 48 selected samples. After the analysis of petrology and sedimentary sequence, the source of sediments and tectonic background and geography were discussed. According the oxide of the important elements and the ratios,efflorescent index and stabilization index, combined with the characters of trace elements, rare earth elements and Eu abnormality, it was found that the mudstone and sand from Cretaceous and Tertiary may be affected by weather and diagenesis,still controlled by tectonic background.
Chen W.,University of Science and Technology of China |
Ding X.,University of Science and Technology of China |
Zhao R.,Institute of Geomechanics |
Shi S.,Henan Institute of Engineering
Environmental Earth Sciences | Year: 2016
The current research presents landslide susceptibility mapping by frequency ratio (FR) and weights of evidence (WoE) models based on geographic information system (GIS) and an assessment of their performances for the Shangzhou District of Shangluo City, China. Firstly, landslide locations of the study area were detected using aerial photographs as well as by carrying outfield survey. Then, a total of 145 landslides were mapped out of which 101 (70 % landslide locations) were randomly selected for training the models, and the remaining 44 (30 % landslide locations) were used for validating the models. The following ten landslide conditioning factors, such as slope aspect, curvature, slope angle, elevation, distance to rivers, distance to faults, lithology, peak ground acceleration, distance to roads and precipitation, were considered in this study. Subsequently, landslide susceptibility maps were produced using FR and WoE models in ArcGIS 10.0 software. The validation of landslide susceptibility maps were carried out using areas under the curve. The validation results showed that the training accuracy were 0.7635 (76.35 %) and 0.7450 (74.50 %) for the FR and WoE models, with predictive accuracy 0.7395 (73.95 %) and 0.7102 (71.02 %), respectively, indicating that landslide susceptibility mapping using FR model is more accurate than WoE model for the study area. © 2015, Springer-Verlag Berlin Heidelberg.
Yin Y.,China Institute of Geo environment Monitoring |
Li B.,Institute of Geomechanics |
Wang W.,China Institute of Geo environment Monitoring
Landslides | Year: 2015
This paper discusses the effect of the May 12, 2008 Wenchuan earthquake on a landslide where stabilization work had taken place and compares the results to sites without stabilization. Contours of shear strain increment and displacement values obtained using a FLAC3D simulation show that the Wangjiayan landslide, which had stabilization work, was stable before the Wenchuan earthquake. Simulations using input strong motion accelerations from the main shock recorded at Qingping station, within the main seismic fault zone, suggest a shear strain increment about 3,000 times more than it was before the main shock. Although the stability of the stabilized landslide decreased during the earthquake, the displacement values were very small. Modeled displacements suggest that the piles played a major role in keeping the slope from sliding. The anti-slide piles were subjected to high shaking acceleration. The strong ground motion records for a time range of 10 to 30 s show that the piles generally experienced accelerations in the range from 0.0 to 3.0 g, with a few spikes of about 5.0 g. Special observation stations were set up to monitor the slope motion at Qingchuan town, 150 km far from the Wangjiayan landslide, along the main central seismic fault zone, after the Wenchuan earthquake. The variation in acceleration with time and the FOS versus time of the Wangjiayan landslide were investigated using these acceleration records of the aftershocks as input data. The aftershock accelerations did not decrease the stability of the Wangjiayan landslide, but an amplification effect on the acceleration of the slope at different elevations was illustrated. © 2014, Springer-Verlag Berlin Heidelberg.