scholarly journals Thickening-upward cycles in deep-marine and deep-lacustrine turbidite lobes: examples from the Clare Basin and the Ordos Basin

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Lei-Fu Zhang ◽  
Da-Zhong Dong
Keyword(s):  
Oil And Gas ◽  
Ordos Basin ◽  
Element Model ◽  
Layer By Layer ◽  
Yanchang Formation ◽  
Oil And Gas Exploration ◽  
Unconventional Oil And Gas ◽  
Sandstone Formation ◽  
Western Ireland ◽  
Bottom To Top

AbstractDeep-marine and deep-lacustrine reservoirs have been targets for conventional and unconventional oil and gas exploration and development for decades. Thickening-upward cycles in the deep-marine Carboniferous Ross Sandstone Formation outcrops in western Ireland and the deep-lacustrine Triassic Yanchang Formation outcrops in southeast Ordos Basin have been investigated and correlated in this study. Typical thickening-upward cycles consisting of, from bottom to top: (1) laminated shales/shales with interbedded siltstone beds; (2) interbedded sandstones/siltstones and mudstones; (3) structureless massive sandstones, are well recognized in these outcrops and are interpreted as turbidite lobes. A continuously prograding lobe-element model is proposed to explain the repeated stacking of thickening-upward cycles. Thickening-upward cycles developed within deep-marine and deep-lacustrine environments are highly comparable in many aspects, such as sedimentary structures, sheet-like geometries and amalgamation features. A frequent and strong degree of amalgamation is developed within the massive sandstone at the top of each thickening-upward cycle, suggesting a layer-by-layer depositional manner. Field observations and comparison with deep-marine counterparts support the occurrence of turbidity flows in the Yanchang Formation, Ordos Basin.

Features of Sandy Debris Flows of the Yanchang Formation in the Ordos Basin and Its Oil and Gas Exploration Significance

2011 ◽  
Vol 85 (5) ◽  
pp. 1187-1202 ◽  
Author(s):  
Xiangbo LI ◽  
Qilin CHEN ◽  
Huaqing LIU ◽  
Yanrong WAN ◽  
Lihua WEI ◽  
...  
Keyword(s):  
Debris Flows ◽  
Oil And Gas ◽  
Ordos Basin ◽  
Yanchang Formation ◽  
Oil And Gas Exploration ◽  
The Ordos Basin

Study on the distribution of extractable organic matter in pores of lacustrine shale: An example of Zhangjiatan Shale from the Upper Triassic Yanchang Formation, Ordos Basin, China

2017 ◽  
Vol 5 (2) ◽  
pp. SF109-SF126 ◽  
Author(s):  
Yuxi Yu ◽  
Xiaorong Luo ◽  
Ming Cheng ◽  
Yuhong Lei ◽  
Xiangzeng Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Storage Capacity ◽  
Ordos Basin ◽  
Organic Content ◽  
Capacity Control ◽  
Yanchang Formation ◽  
Geochemical Characterization ◽  
Extractable Organic Matter

Shale oil and gas have been discovered in the lacustrine Zhangjiatan Shale in the southern Ordos Basin, China. To study the distribution of extractable organic matter (EOM) in the Zhangjiatan Shale ([Formula: see text] ranges from 1.25% to 1.28%), geochemical characterization of core samples of different lithologies, scanning electron microscope observations, low-pressure [Formula: see text] and [Formula: see text] adsorption, and helium pycnometry were conducted. The content and saturation of the EOM in the pores were quantitatively characterized. The results show that the distribution of the EOM in the shale interval is heterogeneous. In general, the shale layers have a higher EOM content and saturation than siltstone layers. The total organic content and the original storage capacity control the EOM content in the shale layers. For the siltstone layers, the EOM content is mainly determined by the original storage capacity. On average, 75% of the EOM occurs in the mesopores, followed by 14% in the macropores, and 11% in the micropores. The EOM saturation in the pores decreases with the increase in pore diameter. The distribution of EOM in the shale pores is closely related to the pore type. Micropores and mesopores developed in the kerogens and pyrobitumens and the clay-mineral pores coated with organic matter are most favorable for EOM retention and charging.

Experimental Analysis on Mechanical Properties of Perforated Casing in Complex Fracturing

2019 ◽  
Vol 944 ◽  
pp. 918-922
Author(s):  
Li Hong Han ◽  
Guang Xi Liu ◽  
Shang Yu Yang ◽  
Peng Wang
Keyword(s):  
Mechanical Properties ◽  
Oil And Gas ◽  
Physical Simulation ◽  
Element Model ◽  
Simulation Test ◽  
Gas Field ◽  
Gas Well ◽  
Fracturing Process ◽  
Oil And Gas Field ◽  
Unconventional Oil And Gas

For unconventional oil and gas well perforating technology, field complex fracturing process to carry out the casing perforation physical simulation test, determine the different perforating process corresponding to the aperture size morphology, based on this, according to the physical simulation test results, perforating casing finite element model is established, the analysis of stress concentration around the perforation under different construction conditions, determine the outer extrusion safety factor, for complex oil and gas field casing string design and provide technical support. Keywords: complex fracturing;perforation; casing; mechanical properties

Classification of Tight Sandstone Reservoir Based on the Conventional Logging

2014 ◽  
Vol 633-634 ◽  
pp. 526-529 ◽  
Author(s):  
Xiao Ling Xiao ◽  
Jia Li Cui ◽  
Yu Peng Zhang ◽  
Xiang Zhang ◽  
Han Wu
Keyword(s):  
Support Vector Machine ◽  
Oil And Gas ◽  
Identification Accuracy ◽  
Support Vector ◽  
Tight Sandstone ◽  
Oil And Gas Exploration ◽  
Unconventional Oil ◽  
Unconventional Oil And Gas ◽  
Sandstone Reservoir

With the increasing social demand for oil and gas resources, the exploration and development of unconventional oil and gas reservoirs will pay more and more attention. Tight sandstone reservoir classification is one of the important tasks in the research of unconventional oil and gas exploration and development.Limitations exist in tight sandstone reservoir classification by various conventional logging.A method for the classification of tight sandstone reservoir based on support vector machine is presented in this paper, combining with the core data and flow unit to establish the reservoir classification standard. Tight sandstone reservoirs of no coring wells are classified based on the model made by support vector machine using conventional logging.The application results show that this method has high suitability and identification accuracy.

scholarly journals Electromagnetic propagation logging while drilling data acquisition method based on undersampling technology

2021 ◽  
Vol 18 (5) ◽  
pp. 653-663
Author(s):  
Xinghan Li ◽  
Wenxiu Zhang ◽  
Wenxuan Chen ◽  
Yali Zhang ◽  
Jian Zheng ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Correction Coefficient ◽  
Sampled Data ◽  
Electromagnetic Propagation ◽  
Oil And Gas Exploration ◽  
Unconventional Oil And Gas ◽  
Logging While Drilling ◽  
Analogue To Digital ◽  
Acquisition Method ◽  
Selection Of

Abstract With the development of complex and unconventional reservoirs, oil and gas exploration becomes increasingly difficult. Highly deviated wells/horizontal wells are widely used. The electromagnetic propagation logging while drilling (LWD) is more effective in complex geological environment detection owing to geological orientation and real-time formation evaluation. However, its operating frequency is generally at the MHz level. Traditional acquisition techniques require an analogue to digital converter with high sampling rates, which will introduce complex circuit structures and increase sampling costs. The undersampling technology has overcome these disadvantages. The difficulties in the undersampling technology include the selection of an undersampling frequency and the acquisition of a signal correction coefficient. The range of undersampling frequencies and a correction coefficient has been developed to process the electromagnetic propagation LWD measurements in this paper. The range of undersampling frequency ensures the validity of the sampled data. The correction coefficient ensures that different frequency signals use the same undersampling frequency to obtain the same frequency recovery signal. The correctness of these parameters is verified by simulation and field data examples. The range of undersampling frequency and a correction coefficient has been applied, improving the data stability and providing reliable technical support for the exploration and development of unconventional oil and gas.

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