Characteristics and influencing factors of Cretaceous reservoir in eastern depression of North Yellow Sea basin

AbstractCretaceous is the key exploration target layer in the eastern depression of North Yellow Sea basin, which has a good prospect for oil and gas exploration. Its huge oil and gas resource potential has attracted great attention from petroleum geologists. In this study, the main rock types, reservoir space types, petrophysical characteristics and main controlling factors of Cretaceous reservoir are studied through core observation, thin section identification, petrophysical analysis and scanning electron microscope observation. The results indicate that the main rock types of Cretaceous reservoir in the eastern depression of North Yellow Sea basin are lithic arkose, feldspar lithic sandstone, some feldspar sandstone and a small amount of lithic sandstone. The average porosity is 6.9%, and the average permeability is 0.46 × 10−3 μm, so Cretaceous reservoir in the study area has poor petrophysical characteristics and belongs to low porosity and low permeability reservoir. Cretaceous reservoirs in the study area mainly develop in secondary pores, which are dominated by dissolution pores (including intragranular pores, intercrystalline pores and cleavage pores), followed by fractures. The main factors affecting petrophysical characteristics of Cretaceous reservoir in the study area are provenance properties, sedimentation, diagenesis (including compaction, cementation and dissolution) and tectonism. The provenance properties and sedimentation are the prerequisite conditions affecting petrophysical characteristics. Petrophysical characteristics of feldspar sandstone of Cretaceous reservoir in the study area and lithic arkose are better than that of feldspar lithic sandstone. Both compaction and cementation reduce the porosity and permeability of Cretaceous reservoir in the study area and make petrophysical characteristics become poor, whereas the dissolution and tectonism play an important role in improving petrophysical characteristics of Cretaceous reservoir.

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Study on the Engineering Geological Properties of Drill Hole in North Yellow Sea

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.1161 ◽

2013 ◽

Vol 353-356 ◽

pp. 1161-1164

Author(s):

Xiao Liu ◽

Xiu Li Feng ◽

Jie Liu

Keyword(s):

Yellow Sea ◽

Oil And Gas ◽

High Strength ◽

Cohesive Soil ◽

Drill Hole ◽

Ocean Engineering ◽

Oil And Gas Exploration ◽

North Yellow Sea ◽

The North ◽

Engineering Geological Properties

The North Yellow Sea basin was located in the middle of the North Yellow Sea. It was possible to find oil and gas reservoirs in this area according to different researches. It was also an oceanic area studied little. In this paper, the engineering geological properties of a drill hole samples collected in the middle of the North Yellow Sea Basin was studied, which could provide basic data for engineering construction and oil and gas exploration and development in this area. In result, stratum of the study area can be divided into 9 units; the mechanical properties of cohesive soil are poor, which have the feature of high compressibility and low shear strength; Granular soil, especially unit 9, has high strength and good engineering property, which is appropriate for use as bearing stratum for drilling platform and other ocean engineering.

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Analysis of pore type and micro pore structure of reservoir in fault basin--Taking Wuerxun depression as an example

E3S Web of Conferences ◽

10.1051/e3sconf/202019405020 ◽

2020 ◽

Vol 194 ◽

pp. 05020

Author(s):

ZHOU Yue ◽

WU Hai-bo

Keyword(s):

Pore Structure ◽

Mineral Composition ◽

Oil And Gas ◽

Authigenic Minerals ◽

Oil And Gas Exploration ◽

Rock Types ◽

Target Layer ◽

Main Factors ◽

Oil Gas ◽

Secondary Pore

Wuerxun depression is the two main oil-bearing depressions in Hailaer basin. Nantun Formation of Wuerxun depression is the most important oil-gas exploration layer, and reservoir characteristics are the main factors controlling oil-gas enrichment. In this paper, the mineral composition and pore type of Nantun Formation reservoir are analyzed by XRD and SEM. It is clear that the main rock types are lithic sandstone and feldspar lithic sandstone. As a whole, it is compact, with poor connectivity of pores and coexistence of primary and secondary pores. Primary pore is mainly residual primary intergranular pore, and secondary pore is the main reservoir space of Nantun Formation, which lays a foundation for further oil and gas exploration. The rock types of the target layer in the study area are mainly lithic sandstone and feldspathic lithic sandstone. Among them, Tongbomiao formation in Wuerxun depression is dominated by conglomerate, while sandstone in Nantun Formation is mainly lithic arkose and feldspathic lithic sandstone; sandstone in Tongbomiao formation and Nantun Formation in Beier depression is dominated by lithic sandstone and feldspathic lithic sandstone. The rocks of Nantun Formation are compact as a whole, with poor connectivity of pores and coexistence of primary and secondary pores. The primary pores are mainly residual primary intergranular pores, mainly of three types. Secondary pore is the main reservoir space of Nantun Formation, including dissolution intergranular pore, dissolution intergranular pore, interstitial matter dissolution pore, intergranular micro pore and micro fracture of authigenic minerals, among which intergranular dissolution pore is the most developed and super large dissolution intergranular pore is the main one.

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Distribution of porosity and permeability in fractured basement reservoir of White Tiger oilfield by core and logging data

Science and Technology Development Journal ◽

10.32508/stdj.v19i1.518 ◽

2016 ◽

Vol 19 (1) ◽

pp. 203-211

Author(s):

Kha Xuan Nguyen ◽

Thanh Quoc Truong ◽

Xuan Van Tran ◽

Son Xuan Pham ◽

Quy Van Hoang

Keyword(s):

Oil And Gas ◽

General Rule ◽

Core Sample ◽

Measuring System ◽

Oil And Gas Exploration ◽

Exploration And Production ◽

Porosity And Permeability ◽

White Tiger ◽

Area North ◽

Favorable Conditions

Determining the porosity and permeability distributions take very important role in the processes of oil and gas exploration and production. With oil fractured basement reservoir, due to high heterogeneity makes assessment even more difficult porosity and permeable. FBR of White Tiger is a typical reservoir with huge dimension world wide special body of world oil production with very large. With more volume and core sample wells measuring system complete log is updated constantly and regularly create favorable conditions for the integration of data from core samples and logging to assess distribution of Fracture basement reservoir White Tiger. In this work we focus on evaluating the distribution center is empty abyss of blocks and blocks north. Through research results show the heterogeneity of permeability of FBR however general rule remains unchanged, the area north of the mine seepage porosity values decreased compared to previous studies.

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Analysis of Seismic Damage Zones: A Case Study of the Ordovician Formation in the Shunbei 5 Fault Zone, Tarim Basin, China

Journal of Marine Science and Engineering ◽

10.3390/jmse9060630 ◽

2021 ◽

Vol 9 (6) ◽

pp. 630

Author(s):

Zhan Zhao ◽

Jingtao Liu ◽

Wenlong Ding ◽

Ruiqiang Yang ◽

Gang Zhao

Keyword(s):

Oil And Gas ◽

Damage Zone ◽

Power Law Distribution ◽

Oil And Gas Development ◽

Factors Affecting ◽

Oil And Gas Exploration ◽

Carbonate Formation ◽

Fault Damage Zone

Fault damage zone has an important influence on subsurface fluid flow and petrophysical properties. Therefore, it is of great significance to study the characteristics of fault damage zone for oil and gas development of ultra-deep carbonate formation. This study uses seismic data and the derived variance attribute to identify two types of damage zones and analyze the spatial geometric characteristics of the damage zones. The results show that the type 1 damage zone is wider than the type 2 damage zone. The width of damage zones distributed on both sides of the Shunbei 5 fault core shows obvious asymmetry, and the damage zone width and throw conforms to the typical power-law distribution on the log-log plot. We discuss the factors affecting the width of the damage zone and its formation process. Finally, we discuss the influence of the damage zones on oil and gas exploration. It seems that the seismic variance attribute is a useful technique for characterizing the ultra-deep strike-slip fault damage zones.

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Study of Sedimentary Microfacies of Putaohua Reservoir at Xu 30 Block in Yushulin Oil Field

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.300 ◽

2014 ◽

Vol 962-965 ◽

pp. 300-304

Author(s):

Ming Qin ◽

Shi Zhong Ma ◽

Zan Gao ◽

Xiao Fei Chen

Keyword(s):

Oil And Gas ◽

Oil Field ◽

Distribution Law ◽

Delta Front ◽

Sedimentary Characteristics ◽

Oil And Gas Exploration ◽

Target Layer ◽

Sedimentary Microfacies ◽

Plane Distribution ◽

Distributary Channel

Xu 30 block is located in the southwest of Yushulin oil field, Putaohua reservoir is the main reservoir. Based on the analysis of the core information and well logging facies elements, and combining with the sedimentary characteristics of the study area, this paper discusses the types of sedimentary microfacies of Xu 30 block in Yushulin oil field in order to guide the future oil and gas exploration and development. The results show that the target layer in the study area having obvious characteristics of underwater distributary channel is delta front facies, and it can be divided into underwater distributary channel, seat body, sheet sand, the inner front sheet sand and the external delta front sedimentary microfacies. Further analysis of sedimentary characteristics, this paper establishes logging microfacies models and draws out 9 time units sedimentary microfacies in plane distribution diagrams. This study can offer not only an important geologic evidence for Putaohua reservoir at Xu 30 block, but also a basement for the distribution law of oil, water and the remaining oil.

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