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Shi Y.,Northeast Petroleum University | Wang W.-H.,Exploration and Development Research Institute of Daqing Oil field Co.
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2012

Surface-related multiple suppression method based on wave equation prediction can handle seismic data from complex subsurface, but the computational cost is high. For filter-based multiple suppression method, its computation efficiency is high, but it is only limited to the seismic data which has enough moveout difference between the primary and multiple. It is difficult to obtain satisfactory suppression effect for the seismic data from complex media, such as velocity reversal. The proposed algorithm combines wave equation prediction with filtering method effectively, surface-related multiple is predicted approximately by the collaborative parallel acceleration calculation from GPU(graphic processing unit) and CPU, followed by comparing and analyzing original data and predicted multiple in the hyperbolic Radon domain. We design an effective adaptive Butterworth-type filter to select the multiple energy from original data in Radon domain. After inverse Radon transform, suppression result can be obtained by subtracting multiple from original data with multiple. The theoretical single-shot data, complex SMAART model and field data are tested by the proposed algorithm. The results demonstrate that the multiple suppression method in the article can breakthrough the limitations of wave equation based method and hyperbolic Radon transform effectively, which can suppress surface-related multiples from complex subsurface efficiently and accurately. Source

Zhao J.,China University of Geosciences | Zhao J.,Exploration and Development Research Institute of Huabei Oil Field Corporation Ltd. | Wan X.Q.,China University of Geosciences | Xi D.P.,China University of Geosciences | And 4 more authors.
Science China Earth Sciences | Year: 2014

Cretaceous climate was warmer than today. The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate. This research is based on core samples from the SK1(S) borehole. The strata sampled are the upper part of the Quantou Formation to member 2 of the Nenjiang Formation, where spores, pollen, dinoflagellates, and other microfossils are abundantly preserved. Based on analysis of the spores and pollen fossils from the core samples, the following six fossil assemblage zones have been recognized in ascending order: The Cicatricosisporites-Cyathidites-Pinuspollenites, Schizaeoisporites-Cyathidites-Classopollis, Cyathidites-Schizaeoisporites, Schizaeoisporites-Cyathidites-Proteacidites, Proteacidites-Cyathidites-Dictyotriletes, and the Lythraites-Callistipollenites-Schizaeoisporites zones. The six fossil zones range from the late Cenomanian to early Campanian. The Late Cretaceous dinoflagellate cysts in the Songliao Basin are of high abundance and low diversity. Specific phytoplankton types reflect salinity changes of the Songliao Lake. Paleoecology of the dinoflagellates suggests that sediments of members 2 and 3 of the Yaojia Formation (K2y2+3) were deposited in a freshwater environment, whereas members 2 and 3 of the Qingshankou Formation (K2q2+3) and members 1 and 2 of the Nenjiang Formation (K2n1+2) were deposited in freshwater to brackish water environments. Combined with the paleoecology of dinoflagellates and the palynomorph biozones, valuable information of the paleoclimate was provided. The quantitative analyses of spores and pollen fossils, such as vegetation type, climate type, and humidity type, diversity and dominance, indicate a relatively sub-humid, mid-subtropical paleoclimate, with slight climatic fluctuation and/or temporal change. © 2014, Science China Press and Springer-Verlag Berlin Heidelberg. Source

Chen S.,University of Science and Technology of China | Jian G.,Beijing Petroleum and Oil Institute | Hou Q.,Beijing Petroleum and Oil Institute | Gao S.,Exploration and Development Research Institute of Daqing Oil field Co. | And 3 more authors.
International Journal of Oil, Gas and Coal Technology | Year: 2013

The enhanced oil recovery (EOR) results of foam flooding depend largely on the stability of foam flow within reservoirs in the presence of crude oil. Experimental studies indicated that oil would impact the foam stability greatly. This paper discussed the effect of oil on the stability of polymer enhanced foams. Two commercial polymers including hydrolysed polyacrylamide (HPAM) and modified polyacrylamide (MPAM) were employed. Mechanism on interaction between foam and oil for experimental foam systems was also studied quantitatively based on several physical-chemical parameters including spreading coefficient, entering coefficient, bridging coefficient and lamella number. The foam stability could be remarkably improved with both HPAM and MPAM. The effect of oil on the stability of polymer enhanced foams could not be fully understood by related coefficient theories. The increase in viscoelasticity of foam films would play a key role in the stability improvement for polymer enhanced foams. Copyright © 2013 Inderscience Enterprises Ltd. Source

Shi Y.,Northeast Petroleum University | Wang W.-H.,Exploration and Development Research Institute of Daqing Oil field Co. | Li Y.,Northeast Petroleum University | Jing H.-L.,Northeast Petroleum University
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2013

Compare with the traditional 2D surface-related multiple prediction algorithm, 3D surface-related multiple prediction approach based on wave equation needs no assumption for underground medium. It is a powerful tool to deal with multiple prediction problem in seismic data processing, which is more conform to the actual situation that seismic wave propagate through the underground medium. Based on the fundamentals of multiple prediction, the matrix representation, calculation approach and realization condition for full 3D surface-related multiple prediction are proposed in this paper. Also using GPU (Graphic Processing Unit) to accelerate full 3D surface-related multiple prediction algorithm, compare to traditional CPU computation, the speed is 165 times faster. Multiple prediction tests are done on synthetic 3D seismic data with surface-related multiples, 2D and 3D surface-related multiple prediction effect from 2D and 3D algorithms are compared and analyzed, and the result demonstrates that full 3D surface-related multiple prediction approach based on wave equation has higher computation accuracy and better prediction effect than 2D algorithm. With the help of reasonable adaptive subtraction, we can obtain seismic prospecting data with high precision after surface-related multiple suppression. Source

Xi D.,China University of Geosciences | Xi D.,CAS Nanjing Institute of Geology and Palaeontology | Cao W.,China University of Geosciences | Huang Q.,Exploration and Development Research Institute of Daqing Oil field Co. | And 8 more authors.
Cretaceous Research | Year: 2016

The Songliao Basin is the largest non-marine oil-bearing basin in China. Because of the absence of substantial evidence, the hypothesis of seawater incursion events into the Songliao Basin remains controversial. The presence of marine fossils could provide direct proof to support this supposition. Here, we report new discoveries of foraminifera, calcareous nannofossils, brackish dinoflagellates, and other marine and brackish-water fossils to support the suggestion of seawater incursion events in the Songliao Basin. Relatively abundant benthic and planktonic foraminifera, calcareous nannofossils, marine and brackish-water dinoflagellates, fish, and bivalves have been discovered in Members 1 and 2 of the Nenjiang Formation, a few foraminifera and brackish-water dinoflagellates have been found in the lower Qingshankou Formation, and just a few brackish-water bivalves have been found in the uppermost Qingshankou Fm. Based on the presence of marine molecular fossils and other evidence, we suggest that relatively large seawater incursion events occurred during the sedimentation of the lower Nenjiang Fm., relatively smaller seawater incursions occurred during the deposition of the lower Qingshankou Fm., and possibly a very small seawater incursion occurred during the sedimentation of the uppermost Qingshankou Fm. These seawater incursion events in the Songliao Basin were controlled by regional tectonic activity, evolution of the palaeo Songliao Lake, and global sea level change. These periodic seawater incursions brought marine biota into the palaeo Songliao Lake. © 2015 Elsevier Ltd. Source

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