Lithology identification and reservoir characteristics of the mixed siliciclastic-carbonate rocks of the lower third member of the Shahejie formation in the south of the Laizhouwan Sag, Bohai Bay Basin, China

2020 ◽  
Vol 35 (2) ◽  
Author(s):  
Yajun Duan ◽  
Jun Xie ◽  
Baichuan Li ◽  
Mengqi Wang ◽  
Tianqi Zhang ◽  
...  
Keyword(s):  
Carbonate Rocks ◽  
Bohai Bay ◽  
The South ◽  
Bohai Bay Basin ◽  
Reservoir Characteristics ◽  
Lithology Identification ◽  
Shahejie Formation

Rock Types and Reservoir Characteristics of Shahejie Formation Marl in Shulu Sag, Jizhong Depression, Bohai Bay Basin

2021 ◽  
Vol 32 (4) ◽  
pp. 986-997
Author(s):  
Jingwei Cui ◽  
Xuanjun Yuan ◽  
Songtao Wu ◽  
Ruifeng Zhang ◽  
Song Jin ◽  
...  
Keyword(s):  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Reservoir Characteristics ◽  
Rock Types ◽  
Shulu Sag ◽  
Shahejie Formation ◽  
Jizhong Depression

Mixed siliciclastic-carbonate deposition and cyclical evolution of the Upper Shahejie formation and its impact on reservoir development in Eocene Huanghekou sag, Bohai Bay Basin, East China

2020 ◽  
pp. 1-47
Author(s):  
Sen Li ◽  
Hongtao Zhu ◽  
Jie Liang ◽  
Du Xiaofeng ◽  
Qingbin Wang ◽  
...  
Keyword(s):  
Carbonate Rocks ◽  
Climate Changes ◽  
Data Sets ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Reservoir Development ◽  
Sandwich Type ◽  
Shahejie Formation ◽  
Sedimentary System ◽  
High Level

We systematically investigated a typical lacustrine mixed siliciclastic-carbonate sedimentary system in this study, which primarily deposited in Eocene Upper Shahejie Formation (Es1 formation) of Huanghekou sag, Bohai Bay Basin. Using synthetic lithological data sets, we summarized eight lithofacies from mixed siliciclastic-carbonate rocks and classified them into siliciclastic- and carbonate-dominated groups, indicating the variation of relative intensity between fluvial/deltaic process and carbonate productivity. Combining petrological and mineral component analysis, most lithofacies are compositionally replaced by micrite dolomite and shown vertically different scales of cyclicity. The high-level cyclicity suggests the alternation between siliciclastic- and carbonate-dominated mixed rocks, while the lower level indicates interbedding of different dolomite-dominated lithofacies. The controlling factors on both levels are different. The higher level is probably controlled by climate changes, which finally resulted in relative variations of siliciclastic supply. While the lower level of cyclicity changes more frequently and is considered to have been controlled by fluctuated hydrodynamic conditions. Typical mixed rocks depositing patterns are summarized as “sandwich type” which mainly distributed at siliciclastic-dominated section and “interbedded type” at carbonate-dominated section. Besides, reservoir physical properties among lithofacies displays significant differences as well, and grain-supported framework of carbonate-dominated lithofacies suggests most constructive in keeping intergranular pores. The investigated lacustrine cyclical sedimentation in mixed siliciclastic-carbonate rocks has been less concerned in previous studies and may serve as a useful reference for lacustrine mixed rocks analysis in other rifted basins.

scholarly journals The influences of sedimentary environments on organic matter enrichment in fine-grained rocks of the Paleogene Shahejie formation in Nanpu Sag, Huanghua Depression, Bohai Bay Basin

2021 ◽  
pp. 014459872110310
Author(s):  
Min Li ◽  
Xiongqi Pang ◽  
Guoyong Liu ◽  
Di Chen ◽  
Lingjian Meng ◽  
...  
Keyword(s):  
Organic Matter ◽  
Source Rocks ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Humid Climate ◽  
High Productivity ◽  
Fine Grained ◽  
Huanghua Depression ◽  
Shahejie Formation ◽  
Nanpu Sag

The fine-grained rocks in the Paleogene Shahejie Formation in Nanpu Sag, Huanghua Depression, Bohai Bay Basin, are extremely important source rocks. These Paleogene rocks are mainly subdivided into organic-rich black shale and gray mudstone. The average total organic carbon contents of the shale and mudstone are 11.5 wt.% and 8.4 wt.%, respectively. The average hydrocarbon (HC)-generating potentials (which is equal to the sum of free hydrocarbons (S1) and potential hydrocarbons (S2)) of the shale and mudstone are 39.3 mg HC/g rock and 28.5 mg HC/g rock, respectively, with mean vitrinite reflectance values of 0.82% and 0.81%, respectively. The higher abundance of organic matter in the shale than in the mudstone is due mainly to paleoenvironmental differences. The chemical index of alteration values and Na/Al ratios reveal a warm and humid climate during shale deposition and a cold and dry climate during mudstone deposition. The biologically derived Ba and Ba/Al ratios indicate high productivity in both the shale and mudstone, with relatively low productivity in the shale. The shale formed in fresh to brackish water, whereas the mudstone was deposited in fresh water, with the former having a higher salinity. Compared with the shale, the mudstone underwent higher detrital input, exhibiting higher Si/Al and Ti/Al ratios. Shale deposition was more dysoxic than mudstone deposition. The organic matter enrichment of the shale sediments was controlled mainly by reducing conditions followed by moderate-to-high productivity, which was promoted by a warm and humid climate and salinity stratification. The organic matter enrichment of the mudstone was less than that of the shale and was controlled by relatively oxic conditions.

The lithologic differences between the third and fourth members of the Eocene Shahejie Formation in the Bohai Bay Basin and the associated climatic evolution

2017 ◽  
Vol 53 (3) ◽  
pp. 788-802 ◽  
Author(s):  
Liangjun Wu ◽  
Fukui Wang ◽  
Dehai Wang ◽  
Mao Fu ◽  
Yuhua Jia
Keyword(s):  
Bohai Bay ◽  
Bohai Bay Basin ◽  
The Third ◽  
Shahejie Formation ◽  
Climatic Evolution

scholarly journals Reservoir Characteristics of Buried-hill Draping Zone in L Oilfield, Offshore China

2021 ◽  
Vol 10 (2) ◽  
pp. 33
Author(s):  
Yujuan Liu ◽  
Qianping Zhang ◽  
Bin Zheng ◽  
Jing Zhang ◽  
Zhaozhao Qu
Keyword(s):  
Seismic Data ◽  
Eastern China ◽  
Seismic Facies ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Sedimentary Characteristics ◽  
Reservoir Characteristics ◽  
Production Practices ◽  
Buried Hill ◽  
Different Parts

The reservoir in different parts of buried-hill draping zone is often quite different, so it is of great significance to clarify the reservoir characteristics for exploration and development. Based on core, well logging, seismic data and production data, reservoir characteristics of oil layer Ⅱ in the lower second member of Dongying Formation of L oilfield, Bohai Bay Basin, offshore eastern China are systematically studied. Analyses of seismic facies, well-seismic combination, paleogeomorphology, and sedimentary characteristics are carried out. Sediment source supply, lake level and buried hill basement geomorphology all contribute to reservoir quality. The research suggests that the different parts of buried-hill draping zone can be divided into four types. Reservoir thickness and physical properties vary. The area where the provenance direction is consistent with the ancient valley direction is a favorable location for the development of high-quality reservoirs. Under the guidance of the results, oilfield production practices in L oilfield offshore China are successful. Knowledge gained from study of L oilfield has application to the development of other similar fields.

Depositional model for lacustrine nearshore subaqueous fans in a rift basin: The Eocene Shahejie Formation, Dongying Sag, Bohai Bay Basin, China

Sedimentology ◽  
2018 ◽  
Vol 65 (6) ◽  
pp. 2117-2148 ◽  
Author(s):  
Yingchang Cao ◽  
Yanzhong Wang ◽  
Jonathan Gordon Gluyas ◽  
Huimin Liu ◽  
Haining Liu ◽  
...  
Keyword(s):  
Bohai Bay ◽  
Depositional Model ◽  
Rift Basin ◽  
Bohai Bay Basin ◽  
Dongying Sag ◽  
Shahejie Formation
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