Stress field modelling of the Late Oligocene tectonic inversion in the Liaodong Bay Subbasin, Bohai Bay Basin (northern China): Implications for geodynamics and petroleum accumulation

<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>

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Control of petroleum traps by Cenozoic tectonic style in the Liaodong Bay area, of the Bohai Bay basin, China

Arabian Journal of Geosciences ◽

10.1007/s12517-016-2311-3 ◽

2016 ◽

Vol 9 (5) ◽

Cited By ~ 2

Author(s):

Mengsi Sun ◽

Chiyang Liu ◽

Shuping Chen ◽

Congjun Feng ◽

Lei Huang

Keyword(s):

Bohai Bay ◽

Liaodong Bay ◽

Bohai Bay Basin ◽

Bay Area ◽

Tectonic Style

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Seismically induced soft-sediment deformation structures in the Palaeogene deposits of the Liaodong Bay Depression in the Bohai Bay basin and their spatial stratigraphic distribution

Sedimentary Geology ◽

10.1016/j.sedgeo.2016.06.014 ◽

2016 ◽

Vol 342 ◽

pp. 78-90 ◽

Cited By ~ 13

Author(s):

Lei Liu ◽

Yijiang Zhong ◽

Hongde Chen ◽

Changgui Xu ◽

Kui Wu

Keyword(s):

Bohai Bay ◽

Soft Sediment ◽

Liaodong Bay ◽

Bohai Bay Basin ◽

Deformation Structures ◽

Sediment Deformation ◽

Soft Sediment Deformation

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Buried Strike-Slip Fault Identification Technique Based on a 3D Stress Body Attribute Considering Formation Deformation and Lithologic Variation

10.2523/iptc-21442-ms ◽

2021 ◽

Author(s):

Wei Wang ◽

Kui Wu ◽

Lin Kang ◽

Xiaobo Huang ◽

Jian Yao

Keyword(s):

Stress Field ◽

Plate Theory ◽

Critical Role ◽

Sudden Change ◽

Strike Slip ◽

The Body ◽

Strike Slip Fault ◽

Wave Number ◽

Bohai Bay ◽

Bohai Bay Basin

Abstract The identification and interpretation of buried strike-slip faults are of great significance int the search for structural traps in oil and gas exploration. However, it is difficult to identify and interpret buried strike-slip faults from seismic profiles and variance slicing, because they may be clear at depth but vague in the shallow. This study proposes a 3D stress body attribute taking into consideration formation deformation and lithologic variation to identify buried strike-slip faults. Taking into account thin plate theory and the generalized Hooke's law, a relationship between stress field, formation deformation and lithologic variation is established. Structural curvature body is used to represent the formation deformation, which is obtained by scanning of the body dip angle and second-order derivation of the wave number domain, while Poisson's ratio and Young's modulus volumes are employed to reflect the spatial lithologic variation, which are calculated by the multivariate linear fitting method or prestack inversion. This technique is applied to the secondary structural interpretation of JinZhou 25-1 oilfield in LiaoDong Bay depression of BoHai Bay Basin. Compared with the 2000 ms variance slice, it can be seen clearly that there is a significant stress concentration zone in the location of LiaoXi buried strike-slip fault from the 3D stress body attribute slice, which is consistent with a sudden change in strata observed on the profile. The LiaoXi buried strike-slip fault has been identified and interpreted. Many structural traps greater than 20km2 have been found along its course. Among them, W structure was drilled in 2016 and about 4.5 million tons of oil was found. This suggests that the spatial distribution of buried strike-slip faults associated with tectonics can be effectively identified through the strength property of the stress field, which is greatly superior to the conventional variance-related methods. It verifies the ability of this technique in the identification and interpretation of strike-slip faults in the entire Bohai Bay Basin and thus its potentially critical role in guiding secondary seismic interpretation.

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