Key Laboratory of Geo detection China University of Geosciences Beijing

Beijing, China

Key Laboratory of Geo detection China University of Geosciences Beijing

Beijing, China
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Peng M.,Key Laboratory of Geo detection China University of Geosciences Beijing | Peng M.,Beijing University of Technology | Jiang M.,Chinese Academy of Geological Sciences | Chen Y.-L.,United Information Technology | And 5 more authors.
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2017

On the eastern margin of the Himalayan orogenic belt, the rapid uplift of the Namche Barwa metamorphic terrane and significant bending of the Yarlung Zangbo suture zone occur. The formation mechanism of the Eastern Himalaya Syntaxis (EHS) is still debated. We used the teleseismic data observed by 48 broadband seismic stations around the Namche Barwa Mountain to estimate P-wave receiver functions and study crustal thickness, VP/VS ratio and crustal structure based on improved H-κ analysis and common conversion point (CCP) stacking method. The results demonstrate that the average crustal thickness is about 64.03 km with most stations ranging from 60.48 km to 66.55 km and the average VP/VS ratio is about 1.728 with most stations ranging from 1.696 to 1.742. The crust thickness exhibits drastic lateral variation beneath the EHS, which is thicker in the western and northern area and thinner in the middle area, thus the crust of the EHS presents an uplifting structural feature. The Moho boundary is uplifted about 6~7 km in the W-E direction, and more than 9~10 km in the N-S direction. The uplifted Moho boundary is formed because high-density and high-velocity lithospheric tearing slab could be delaminated and sank into asthenosphere in the upper mantle and result in unbalanced gravity. The anomaly of the average VP/VS ratio, which is more than 1.8, is distributed on both sides of the EHS, which can be interpreted as a crustal partial melting body around the EHS. The uplifting Moho beneath the EHS and the existence of partial melting in the crust might be associated with the upwelling of hot mantle material, and the upwelling of the asthenosphere may be caused by a tear of the India plate. © 2017, Science Press. All right reserved.

Jiang G.,Key Laboratory of Geo detection China University of Geosciences Beijing | Jiang G.,Beijing University of Technology | Zhao D.,Tohoku University | Zhang G.,Beijing University of Technology
Physics of the Earth and Planetary Interiors | Year: 2015

Seismic tomography and numerical simulations show that the western Pacific slab bends horizontally when it reaches the boundary between the upper mantle and lower mantle beneath northeast Asia. It is expected that a metastable olivine wedge (MOW) exists in the cold core of the slab because of a delayed phase transition from olivine to its high-pressure polymorphs. However, it is still debated whether the MOW actually exists or not, and even if it exists, its physical properties, such as seismic velocity and density, are still unclear. In this work we use high-quality arrival-time data of 17 deep earthquakes occurring within the Pacific slab under northeast Asia to study the detailed structure of the slab. The deep earthquakes are relocated precisely by applying a modified double-difference location method to arrival-time data recorded at both Chinese and Japanese stations. Based on the precise hypocentral locations, a forward modeling method and differential travel-time residuals data are used to estimate seismic velocity within the deep source zone, which can decrease or remove the influence of ambient velocity heterogeneities. Our results show that the MOW does exist within the Pacific slab under northeast Asia, and the MOW has a mean velocity anomaly of 7-9% lower than the iasp91 Earth model. The existence of MOW in the slab has important geodynamic implications. It can reduce the speed of slab subduction and affect the generation of deep earthquakes. © 2014 Elsevier B.V.

He X.,Beijing University of Technology | He X.,Key Laboratory of Geo Detection China University of Geosciences Beijing | Wang Y.,Beijing University of Technology | Wang Y.,Key Laboratory of Geo Detection China University of Geosciences Beijing | Zhang Y.,Sinopec
Journal of Computational and Theoretical Nanoscience | Year: 2016

Aiming at the corrosion problem of CO2/Foam Flooding in Honghe 156 well group, the corrosion inhibiting performance of a synthesized amphoteric imidazoline corrosion inhibitor HGC2-2 was evaluated by rotary coupon test, and the corrosion inhibition mechanism was studied through the electrochemical tests. The results showed that, under the condition of optimum concentration 500 mg/L, the corrosion inhibiting effect of HGC2-2 could reach 90% on N80 steel. The corrosion inhibitor HGC2-2 had an excellent compatibility with the foaming agent. The corrosion inhibitor HGC2-2 also had a good adaptability to temperature and CO2 partial pressure. The electrochemical tests results showed that, the corrosion inhibitor HGC2-2 could inhibit both the anodic reaction and the cathodic reaction. The adsorption of HGC2-2 molecule on the surface of metals was in conformity with the Langmuir adsorption isotherm, and the adsorption between HGC2-2 molecule and the surface of metals had strongly chemical interaction. The field test results showed that, the corrosion inhibitor HGC2-2 could decrease the corrosion rate of injection process to below 0.076 mm/a, meanwhile could decrease the corrosion the production process greatly. The content of iron ion in the production water from two gas channeling wells got a reduction of 79.1% and 80.9% respectively. © Copyright 2016 American Scientific Publishers All rights reserved.

Shi C.,Beijing University of Technology | Shi C.,Key Laboratory of Geo Detection China University of Geosciences Beijing | Shi C.,Sinopec | Wang Y.,Beijing University of Technology | And 2 more authors.
Journal of Computational and Theoretical Nanoscience | Year: 2016

Using the standard curve of potassium permanganate-diphenyl carbazi dissector photometric, the absorbance of chromium in water was determined. Oxalic acid, ammonium oxalate, ethylene diamine tetra-acetic acid disodium, which had the highest removal rate, were determined as the chromium(III) removal agent; Then the amount of calcium hydroxide was optimized. The amount of calcium hydroxide was 150% in oxalic acid, 100% in ammonium oxalate and 200% in ethylene diamine tetra-acetic acid disodium. Finally, aluminum chloride was determined as the co-precipitating agent. The results showed that the removal rate of chromium(III) could reach to 99.9%, and the content of chromium(III) was less than 0.026 mg/L. © Copyright 2016 American Scientific Publishers All rights reserved.

Tan M.,Key Laboratory of Geo detection China University of Geosciences Beijing | Tan M.,China University of Geosciences | Song X.,China University of Geosciences | Yang X.,Sinopec | Wu Q.,Sinopec
Journal of Natural Gas Science and Engineering | Year: 2015

Organic shale is one of the most important unconventional oil and gas resources. Hydrocarbon potential prediction of organic shale such as total organic carbon (TOC) is an important evaluation tool, which primarily uses empirical equations. A support-vector machine is a set of supervised tools used for classification and regression problems. In this study, a support-vector machine for regression (SVR) is investigated to estimate the TOC content in gas-bearing shale. First, SVR technology is introduced including its basic concepts, associated regression algorithms and kernel functions, and a TOC prediction sketch that uses wireline logs. Then, one example is considered to compare three different regression algorithms and four different kernel functions in a packet dataset validation process and a leave-one-out cross-validation process. Error analysis indicates that the SVR method with the Epsilon-SVR regression algorithm and the Gaussian kernel produces the best results. The method of choosing the optimum Gamma value in the Gaussian kernel function is also introduced. Next, for comparison, the SVR-derived TOC with the optimal model and parameters is compared with the empirical formula and the δlogR methods. Finally, in a real continuous TOC prediction using wireline logs, TOC prediction tests are performed using SVR to choose the optimal logs as inputs, and the optimal input is finally chosen. Additionally, the radial basis network (RBF) is also applied to perform tests with different inputs; the results of these tests are compared with those of the SVR method. This study shows that SVR technology is a powerful tool for TOC prediction and is more effective and applicable than a single empirical model, δlogR and some network methods. © 2015 Elsevier B.V.

Zhou J.,Key Laboratory of Geo detection China University of Geosciences Beijing | Zhou J.,Beijing University of Technology | Meng X.,Key Laboratory of Geo detection China University of Geosciences Beijing | Meng X.,Beijing University of Technology | And 4 more authors.
Journal of Applied Geophysics | Year: 2015

Three-dimensional cross-gradient joint inversion of gravity and magnetic data has the potential to acquire improved density and magnetization distribution information. This method usually adopts the commonly held assumption that remanent magnetization can be ignored and all anomalies present are the result of induced magnetization. Accordingly, this method might fail to produce accurate results where significant remanent magnetization is present. In such a case, the simplification brings about unwanted and unknown deviations in the inverted magnetization model. Furthermore, because of the information transfer mechanism of the joint inversion framework, the inverted density results may also be influenced by the effect of remanent magnetization. The normalized magnetic source strength (NSS) is a transformed quantity that is insensitive to the magnetization direction. Thus, it has been applied in the standard magnetic inversion scheme to mitigate the remanence effects, especially in the case of varying remanence directions. In this paper, NSS data were employed along with gravity data for three-dimensional cross-gradient joint inversion, which can significantly reduce the remanence effects and enhance the reliability of both density and magnetization models. Meanwhile, depth-weightings and bound constraints were also incorporated in this joint algorithm to improve the inversion quality. Synthetic and field examples show that the proposed combination of cross-gradient constraints and the NSS transform produce better results in terms of the data resolution, compatibility, and reliability than that of separate inversions and that of joint inversions with the total magnetization intensity (TMI) data. Thus, this method was found to be very useful and is recommended for applications in the presence of strong remanent magnetization. © 2015.

Zhang F.-Q.,Key Laboratory of Geo Detection China University of Geosciences Beijing | Wei F.-J.,Sinopec | Wang Y.-C.,Key Laboratory of Geo Detection China University of Geosciences Beijing | Wang W.-J.,Petrochina | Li Y.,Petrochina
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2013

AVO forward modeling is always constructed by the approximation of Zoeppritz equation in traditional three-term AVO inversion. But the approximation is limited in the case of critical angle and elastic parameters varying severely. Given this problem, we can use the exact Zoeppritz equation to construct the inversion objective function. Because the relationship between P wave reflection coefficient and elastic parameters is nonlinear, the common approach is to use nonlinear optimization algorithm which hasn't been widespread because of the large computation. The alternative is to use generalized linear inversion which uses the linear equation to express the nonlinear relation through the expansion of P wave reflection coefficient into a truncated Taylor series. The GLI can get high accuracy through several iterations in theory. But GLI is unstable sometimes because of the large conditional number of Jacobian matrix. Bayesian inversion combines the prior distribution of model parameters with the likelihood function of the noise to form the posterior distribution of model parameters, which transforms the minimization of objective function into the maximization of the posterior probability distribution. Because of the introduction of the prior information of model parameters, the ill-posed problem can be reduced dramatically. This article combines the ideas of the two methodologies, which uses the idea of GLI to construct AVO forward modeling for improving the accuracy of inverting the large incident angle seismic data and uses Bayesian theory to introduce the model parameters prior information to construct the regularization of inversion objective function for reducing the ill-posed problem of inversion. This algorithm assumes that the prior distribution of the model parameters honors trivariate Cauchy distribution.

Tan M.,Key Laboratory of Geo detection China University of Geosciences Beijing | Tan M.,Beijing University of Technology | Wang P.,Beijing University of Technology | Mao K.,Sinopec
Journal of Applied Geophysics | Year: 2014

Three-dimensional nuclear magnetic resonance (3D NMR) logging can simultaneously measure transverse relaxation time (T2), longitudinal relaxation time (T1), and diffusion coefficient (D). These parameters can be used to distinguish fluids in the porous reservoirs. For 3D NMR logging, the relaxation mechanism and mathematical model, Fredholm equation, are introduced, and the inversion methods including Singular Value Decomposition (SVD), Butler-Reeds-Dawson (BRD), and Global Inversion (GI) methods are studied in detail, respectively. During one simulation test, multi-echo CPMG sequence activation is designed firstly, echo trains of the ideal fluid models are synthesized, then an inversion algorithm is carried on these synthetic echo trains, and finally T2-T1-D map is built. Futhermore, SVD, BRD, and GI methods are respectively applied into a same fluid model, and the computing speed and inversion accuracy are compared and analyzed. When the optimal inversion method and matrix dimention are applied, the inversion results are in good aggreement with the supposed fluid model, which indicates that the inversion method of 3D NMR is applieable for fluid typing of oil and gas reservoirs. Additionally, the forward modeling and inversion tests are made in oil-water and gas-water models, respectively, the sensitivity to the fluids in different magnetic field gradients is also examined in detail. The effect of magnetic gradient on fluid typing in 3D NMR logging is stuied and the optimal manetic gradient is choosen. © 2014.

Tan M.,Key Laboratory of Geo detection China University of Geosciences Beijing | Tan M.,Beijing University of Technology | Peng X.,Beijing University of Technology | Cao H.,Sinopec | And 2 more authors.
Journal of Petroleum Science and Engineering | Year: 2015

Gas-bearing shale is one of the most important unconventional reservoirs. Shear wave velocities are essential for prestack AVO analysis, fracture identification, and fluid typing. Moreover, the recent studies of shear wave prediction mostly focused on conventional sandstones, wet shale, sandstone or carbonate rock may not be suitable for gas-bearing shale. Firstly, according to core analysis results of gas-bearing shale, petrophysics model is proposed. Then, shear wave prediction method based on Gasmann's theory, spatial averaging model, and elastic moduli of dry rock were studied in detail. Especially, point to organic shale with low porosity, Krief, Nur, and Pride models are selected to calculate the elastic moduli of dry rock, respectively, and the best critical porosity in Nur model and consolidation coefficient in Pride model are determined, which is virtual to gas-bearing shale. Pride model is finally optimized as the most suitable model through comparison of error analysis. Meanwhile, to implement the estimation of shear wave from well logs, a corresponding log interpretation method for gas-bearing shale is also studied. In case study, calculated volumetric concentrations of minerals are in good agreement with X-ray diffraction (XRD) analysis of cores. The final shear wave velocity also matches well with dipole sonic imaging (DSI) log. Therefore, the whole approach is verified correct and suitable for estimation of shear velocity or slowness in gas-bearing shale. © 2015 Elsevier B.V..

Liu Z.,Beijing University of Technology | Liu Z.,Key Laboratory of Geo detection China University of Geosciences Beijing | Huang J.,Beijing University of Technology | Huang J.,Key Laboratory of Geo detection China University of Geosciences Beijing | And 2 more authors.
Physics of the Earth and Planetary Interiors | Year: 2016

The ambient noise data recorded by 249 seismic stations in the permanent and temporary networks in Northeast China are used to invert for the isotropic phase velocity and azimuthal anisotropy of Rayleigh waves in the period band 5-50 s. The inversion results reflect the structure from the shallow crust to upper mantle up to approximately 120 km depth. Beneath the Songliao basin, both the fast direction in shallow crust and strike of a low-velocity anomaly in the middle crust are NNE-SSW, which is coincident with the main tectonic trend of the (Paleo) Pacific tectonic domain. This indicates that the rifting of the Songliao basin is influenced by the subduction of (Paleo) Pacific plate. The upper mantle of Songliao block (except the central area of Songliao basin) to the west of Mudanjiang fault, and the east of the North-South Gravity Lineament, is characterized by high-velocity and weak anisotropy up to approximately 120 km depth. We infer that there is delamination of lithospheric mantle beneath the Songliao block. Obvious N-S, NE-SW, and E-W trending fast directions are found in the lithospheric mantles of the east, west, and south sides of Songliao block, respectively, which coincide with the strikes of the Paleozoic tectonic in these areas. This suggests that the frozen-in anisotropic fabric in the lithospheric mantle can be used to indicate the historical deformation of the lithosphere. In the northern margin of the North China Craton, the spatial variations of phase velocity and azimuthal anisotropy are more dramatic than those in Northeast China blocks, which indicates that the lithosphere of the North China Craton has experienced more complicated tectonic evolution than that of the Northeast China blocks. © 2016 Elsevier B.V.

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