Sedimentary Facies, Sequence Stratigraphic Patterns in Pre-Cenozoic Inland Compressional Basin: Example from Early Yanshanian Succession of Eastern Yihezhuang Salient, Jiyang Depression, Bohai Bay Basin, China

2018 ◽  
Vol 30 (1) ◽  
pp. 194-205 ◽  
Author(s):  
Guangzeng Song ◽  
Hua Wang ◽  
Meng Xu ◽  
Jinda Xu ◽  
Guoqing Sang
Keyword(s):  
Sedimentary Facies ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Jiyang Depression ◽  
Sequence Stratigraphic ◽  
Early Yanshanian

Predictive distribution of high-quality tight reservoirs of coarse clastic rocks by linking diagenesis to sedimentary facies: Evidence from the upper Sha 4 Member in the northern Bonan Sag, Bohai Bay Basin, eastern China

2018 ◽  
Vol 6 (2) ◽  
pp. T413-T429 ◽  
Author(s):  
Dong Wu ◽  
Xiantai Liu ◽  
Yushan Du ◽  
Long Jiang ◽  
Ziyan Cheng
Keyword(s):  
Eastern China ◽  
Sedimentary Facies ◽  
Middle Part ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
High Quality ◽  
Clastic Rocks ◽  
Bonan Sag ◽  
Tight Reservoirs ◽  
Channel Deposits

Coarse clastic rocks of the upper Sha 4 Member in the northern Bonan Sag of the Bohai Bay Basin in eastern China are important hydrocarbon reservoirs. The deposits are tight reservoirs owing to the low porosity (less than 10%) and low permeability (less than 1 mD). Because of the strong heterogeneity, although the reserve in the northern Bonan Sag is remarkable, only 4.9% of the reserves are recovered. We have studied these tight reservoirs by linking diagenesis to sedimentary facies to help predict the distribution of high-quality tight reservoirs. Petrographic analysis is undertaken based on cores, thin sections, X-ray diffraction and scanning electron microscope, helpful to understand the impacts on tight reservoirs of sedimentary factors and diagenesis factors. Sedimentary microfacies, lithologic characteristics, reservoir property, diagenesis, and diagenetic minerals are studied. Coarse clastic rocks are deposited mainly in nearshore subaqueous fans and fan deltas. The multistage sandstones are the valid reservoirs of coarse clastic rocks and dominated by feldspathic litharenite, lithic arkose, and arkose. The reservoir property is poor principally owing to the strong compaction and cementation. Pores are composed of secondary pores and primary pores. The secondary pore, generated in the dissolution of detrital minerals and/or cements, is the major type of pores and important to porosity improvement. By linking diagenesis to sedimentary facies, it can be concluded that high-quality tight reservoirs of coarse clastic rocks of the upper Sha 4 Member in the northern Bonan Sag of Bohai Bay Basin in eastern China are associated with medium to coarse-grain sandstones, found in the middle part of underwater distributary channel deposits in fan deltas and in the middle part of underwater channel deposits in nearshore subaqueous fans, with abundant secondary porosity but low cement contents, vertically at depths ranging from 3500 to 4100 m.

Hydrocarbon generation and evolution of the source rocks of the lower Es3 and upper Es4 members of the Shahejie Formation in the Niuzhuang Sub-sag, Jiyang Depression, Bohai Bay Basin, eastern China

2018 ◽  
Vol 6 (4) ◽  
pp. SN11-SN21
Author(s):  
Zhenkai Huang ◽  
Maowen Li ◽  
Quanyou Liu ◽  
Xiaomin Xie ◽  
Peng Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Eastern China ◽  
Source Rocks ◽  
Bohai Bay ◽  
Hydrocarbon Generation ◽  
Bohai Bay Basin ◽  
Jiyang Depression ◽  
Generation Threshold ◽  
Oil Generation ◽  
Shahejie Formation

Systematic organic petrology and geochemistry analyses have been conducted in the source rocks of the lower Es3 and upper Es4 members of the Shahejie Formation in the Niuzhuang Sub-sag, Jiyang Depression, Bohai Bay Basin, eastern China. The results indicate that the main organic types of shale and nongypsum mudstone in the lower Es3 and upper Es4 member are I-II1 kerogen, and the predominant ([Formula: see text]) activation energy frequencies range from 57 to [Formula: see text]. The similar distribution characteristics in the two source rocks indicate that they have a similar hydrocarbon maturation process. An extensive pyrolysis analysis indicates that the source rocks of the upper Es4 member do not have an obvious double peak hydrocarbon generation model. Previous studies indicate that the hydrocarbon index peak at a depth of 2500–2700 m is affected by migrating hydrocarbon. Major differences are not observed in the hydrocarbon generation and evolution process of the shale and nongypsum mudstone. The primary oil generation threshold of the lower Es3 and upper Es4 members is approximately 3200 m, and the oil generation peak is approximately 3500 m. The activation energy distribution of the gypsum mudstone of the upper Es4 member is wider than that of the shale and nongypsum mudstone, and lower activation energies account for a larger proportion of the activation energies. The above factors may lead to a shallower oil generation threshold for gypsum mudstone compared with that for shale and nongypsum mudstone.

Fault System Evolution and Its Influences on Buried-hills Formation in Tanhai Area of Jiyang Depression, Bohai Bay Basin, China

2020 ◽  
Author(s):  
Meng Zhang ◽  
Zhiping Wu ◽  
Shiyong Yan
Keyword(s):  
Stress Field ◽  
Cross Sections ◽  
Large Scale ◽  
Structural Evolution ◽  
Fault System ◽  
Mountain Range ◽  
Bohai Bay ◽  
Thrust Faults ◽  
Bohai Bay Basin ◽  
Jiyang Depression

<p>Buried-hills, paleotopographic highs covered by younger sediments, become the focused area of exploration in China in pace with the reduction of hydrocarbon resources in the shallow strata. A number of buried-hill fields have been discovered in Tanhai area located in the northeast of Jiyang Depression within Bohai Bay Basin, which provides an excellent case study for better understanding the structural evolution and formation mechanism of buried-hills. High-quality 3-D seismic data calibrated by well data makes it possible to research deeply buried erosional remnants. In this study, 3-D visualization of key interfaces, seismic cross-sections, fault polygons maps and thickness isopach maps are shown to manifest structural characteristics of buried-hills. Balanced cross-sections and fault growth rates are exhibited to demonstrate the forming process of buried-hills. The initiation and development of buried-hills are under the control of fault system. According to strike variance, main faults are grouped into NW-, NNE- and near E-trending faults. NW-trending main faults directly dominate the whole mountain range, while NNE- and near E-trending main faults have an effect on dissecting mountain range and controlling the single hill. In addition, secondary faults with different nature complicate internal structure of buried-hills. During Late Triassic, NW-trending thrust faults formed in response to regional compressional stress field, preliminarily building the fundamental NW-trending structural framework. Until Late Jurassic-Early Cretaceous, rolling-back subduction of Pacific Plate and sinistral movement of Tan-Lu Fault Zone (TLFZ) integrally converted NW-trending thrust faults into normal faults. The footwall of NW-trending faults quickly rose and became a large-scale NW-trending mountain range. The intense movement of TLFZ simultaneously induced a series of secondary NNE-trending strike-slip faults, among which large-scale ones divided the mountain range into northern, middle and southern section. After entry into Cenozoic, especially Middle Eocene, the change of subduction direction of Pacific Plate induced the transition of regional stress field. Near E-trending basin-controlling faults developed and dissected previous tectonic framework. The middle section of mountain range was further separated into three different single hill. Subsequently, the mountain range was gradually submerged and buried by overlying sediments, due to regional thermal subsidence. Through multiphase structural evolution, the present-day geometry of buried-hills is eventually taken shape.</p>

scholarly journals Genetic connection between mud shale lithofacies and shale oil enrichment in Jiyang Depression, Bohai Bay Basin

2016 ◽  
Vol 43 (5) ◽  
pp. 759-768 ◽  
Author(s):  
Yong WANG ◽  
Xuejun WANG ◽  
Guoqi SONG ◽  
Huimin LIU ◽  
Deshun ZHU ◽  
...  
Keyword(s):  
Bohai Bay ◽  
Shale Oil ◽  
Bohai Bay Basin ◽  
Jiyang Depression

The Décollement Structures in Jiyang Depression, Bohai Bay Basin, China

2008 ◽  
Vol 51 (2) ◽  
pp. 367-377
Author(s):  
Li LI ◽  
Da-Lai ZHONG ◽  
Chang-Chun YANG ◽  
Xiu-Peng SHI ◽  
Hong-Bo GONG
Keyword(s):  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Jiyang Depression
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