Niu X.,National Engineering Laboratory for Exploration and Development of Low permeability Oil and Gas Field |
Niu X.,Petrochina |
Hou G.,Peking University |
Zhang J.,National Engineering Laboratory for Exploration and Development of Low permeability Oil and Gas Field |
And 10 more authors.
Geotectonica et Metallogenia | Year: 2014
Member 6 and 7 tight sand of the Triassic Yanchang Formation are developed in the central Ordos basin of the North China craton, and have prospective exploration potential in tight sand oil and gas. The structural fractures assessment critera of Member 6 and 7 tight sands are proposed in this paper based on the measurement, statistics and analysis of fractures in the cores sampled from 107 wells. The goal is to search for the difference in the horizontal and vertical structural fracture assessment columns. High density of fractures of Member 71 is developed in the eastern and southeastern Longdong area, especially in Qingyang where the density of fractures, is the highest. High density of fractures of Member 71 is developed in the northeastern Shanbei, higher than that of the southwestern Shanbei area. High density of fractures of Member 72 is developed among Qingyang, Qingcheng and Heshui, especially near the Z78 and Zhengning area, but the density of fractures in the western and northern Longdong areas is rather low. The highest density of fractures of Member 72 is developed in the western Shanbei, and the second-highest density of fractures is seen in the northwestern Wuqi area, whereas the density of fractures is very low in the other areas of the central Ordos basin.
Wang D.Y.,Beijing Normal University |
Xin B.S.,Beijing Normal University |
Yang H.,Petrochina |
Yang H.,National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Field |
And 4 more authors.
Science China Earth Sciences | Year: 2014
A table tuff interlayer at the bottom of Chang-7 Member of Yanchang Formation, the Ordos Basin, may serve as an indicator for stratigraphic division and correlation. In this study, zircon SHRIMP U-Pb dating was performed on the tuff at the bottom of Chang-7 Member using samples from wells Luo-36 and Zhuang-211 in the southwest of the basin, which yielded weighted average 206Pb/238U ages of 241.3±2.4 and 239.7±1.7 Ma, respectively. The cathodoluminescence images and the U/Th element ratio of tuff indicate that the zircons are magmatogenic and their ages represent that of the sedimentation age of the tuff at the bottom of Chang-7, which is 239.7–241.3 Ma in age. This finding confirms presence of the Middle Triassic strata at the bottom of Yanchang Formation. Taking previous findings into account, we suggest restricing the Late Triassic Yanchang Formation sensu stricto to the interval from Chang-7 to Chang-1 and assigning the interval from Chang-10 to Chang-8 as the Tongchuan Formation. The tuff at the bottom of the Chang-7 Member of Yanchang Formation represents the sedimentary response to the Qinling orogenic event in the early Indosinian. This tectonic event resulted in major changes in paleogeomorphology and the sedimentary environment of the lake basin during deposition of the Yanchang Formation. During this period, extremely favourable conditions were present for subsequent hydrocarbon generation and pooling of lake basin. © 2014, Science China Press and Springer-Verlag Berlin Heidelberg.
Wang C.-C.,China University of Petroleum - East China |
Yao J.,China University of Petroleum - East China |
Yang Y.-F.,China University of Petroleum - East China |
Zhang L.,China University of Petroleum - East China |
And 4 more authors.
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2012
With two different resolution SEM images, 3D macro-pore and micro-pore digital cores were constructed respectively by the simulated annealing method. Then a superposition method was proposed to construct the carbonate digital core which could describe different pore characteristics. Finally, lattice Boltzmann method was used to analyze the percolation properties. The results show that the simulated annealing method could reconstruct the 3D digital core with good connectivity. The superposition digital core could capture both the pore properties of macro-pore and micro-pore digital core, and the permeability of superposition digital core (1.64×10-3μm2) is even higher than the permeability sum of macro digital core (1.12×10-3μm2) and micro digital core (0.036×10-3μm2), which show that the micro-pore has an important influence on connectivity in carbonate rocks.
Li X.W.,National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Field |
Li X.W.,Gas Technology Institute |
Xu C.M.,National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Field |
Xu C.M.,Gas Technology Institute |
And 4 more authors.
Advanced Materials Research | Year: 2013
This paper from the research of the porous medium pore structure characteristics of ultra-low permeability reservoir, combined the core flow test with reservoir characteristics analysis and fluid properties analysis studying the reservoir water injection development effect. The research results show that: the microscopic heterogeneity of ultra-low permeability reservoir is strong, pore connectivity of porous medium is poor, seepage throat is very fine and microcrack is growth. During the process of water injection development there exist particle migration phenomenon, could easily cause pore throat blockage, and lead to water injection pressure rebound. According to the research result targeted on the organic mud acid deep broken down experiment, the result shows that it can achieve the purpose of depressure and increasing injection rate. © (2013) Trans Tech Publications, Switzerland.