Natural Fracture and Cleat Patterns in Coalbed and Shale Gas Reservoirs of the Donets Basin (Ukraine)

Author(s):  
V.A. Pryvalov ◽  
O.A. Panova ◽  
R.F. Sachsenhofer
Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Xiaofei Shang ◽  
Huawei Zhao ◽  
Shengxiang Long ◽  
Taizhong Duan

Shale gas reservoir evaluation and production optimization both require geological models. However, currently, shale gas modeling remains relatively conventional and does not reflect the unique characteristics of shale gas reservoirs. Based on a case study of the Fuling shale gas reservoir in China, an integrated geological modeling workflow for shale gas reservoirs is proposed to facilitate its popularization and application and well improved quality and comparability. This workflow involves four types of models: a structure-stratigraphic model, reservoir (matrix) parameter model, natural fracture (NF) model, and hydraulic fracture (HF) model. The modeling strategies used for the four types of models vary due to the uniqueness of shale gas reservoirs. A horizontal-well lithofacies sublayer calibration-based method is employed to build the structure-stratigraphic model. The key to building the reservoir parameter model lies in the joint characterization of shale gas “sweet spots.” The NF models are built at various scales using various methods. Based on the NF models, the HF models are built by extended simulation and microseismic inversion. In the entire workflow, various types of models are built in a certain sequence and mutually constrain one another. In addition, the workflow contains and effectively integrates multisource data. Moreover, the workflow involves multiple model integration processes, which is the key to model quality. The selection and optimization of modeling methods, the innovation and development of modeling algorithms, and the evaluation techniques for model uncertainty are areas where breakthroughs may be possible in the geological modeling of shale gas reservoirs. The workflow allows the complex process of geological modeling of shale gas reservoirs to be more systematic. It is of great significance for a dynamic analysis of reservoir development, from individual wells to the entire gas field, and for optimizing both development schemes and production systems.


2014 ◽  
Vol 2 (2) ◽  
pp. SE55-SE62 ◽  
Author(s):  
Shukun Yuan ◽  
Michael V. DeAngelo ◽  
Bob A. Hardage

Evaluating and exploiting unconventional complex oil and gas reservoirs such as the Marcellus Shale gas reservoirs within the Appalachian Basin in Pennsylvania, USA, have gained considerable interest in recent years. Technologies such as conventional 3D seismic, horizontal drilling, and hydraulic fracturing have been at the forefront of the effort to exploit these resources. Recently, multicomponent seismic technologies have been integrated into some resource evaluation and reservoir characterization activities of low-permeability rock systems. We evaluated how multicomponent seismic technology provides value to reservoir characterization in shale gas exploration. We improved fault interpretations and natural fracture identifications by means of [Formula: see text] and [Formula: see text] integrated interpretation. In addition, using P-P-/P-SV-joint inversion, we extracted key parameters, such as [Formula: see text] ratio and density, that improve stratigraphic interpretation and rock-property descriptions of shale gas reservoirs.


2019 ◽  
Vol 22 (3) ◽  
pp. 299-320 ◽  
Author(s):  
Guanglong Sheng ◽  
Ting Xu ◽  
Feifei Gou ◽  
Yuliang Su ◽  
Wendong Wang ◽  
...  

Author(s):  
Jiang Xie ◽  
Seong H. Lee ◽  
Zhiming Wang ◽  
Xian-Huan Wen

Author(s):  
Roger Yuan ◽  
Fa Dwan ◽  
Navpreet Singh ◽  
Liang Jin ◽  
Danny Soo ◽  
...  

Author(s):  
Dianshi Xiao ◽  
Shuangfang Lu ◽  
Mingli Shao ◽  
Nengwu Zhou ◽  
Renwen Zhao ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
pp. 219
Author(s):  
Jing Zeng ◽  
Alexey Stovas ◽  
Handong Huang ◽  
Lixia Ren ◽  
Tianlei Tang

Paleozoic marine shale gas resources in Southern China present broad prospects for exploration and development. However, previous research has mostly focused on the shale in the Sichuan Basin. The research target of this study is expanded to the Lower Silurian Longmaxi shale outside the Sichuan Basin. A prediction scheme of shale gas reservoirs through the frequency-dependent seismic attribute technology is developed to reduce drilling risks of shale gas related to complex geological structure and low exploration level. Extracting frequency-dependent seismic attribute is inseparable from spectral decomposition technology, whereby the matching pursuit algorithm is commonly used. However, frequency interference in MP results in an erroneous time-frequency (TF) spectrum and affects the accuracy of seismic attribute. Firstly, a novel spectral decomposition technology is proposed to minimize the effect of frequency interference by integrating the MP and the ensemble empirical mode decomposition (EEMD). Synthetic and real data tests indicate that the proposed spectral decomposition technology provides a TF spectrum with higher accuracy and resolution than traditional MP. Then, a seismic fluid mobility attribute, extracted from the post-stack seismic data through the proposed spectral decomposition technology, is applied to characterize the shale reservoirs. The application result indicates that the seismic fluid mobility attribute can describe the spatial distribution of shale gas reservoirs well without well control. Based on the seismic fluid mobility attribute section, we have learned that the shale gas enrich areas are located near the bottom of the Longmaxi Formation. The inverted velocity data are also introduced to further verify the reliability of seismic fluid mobility. Finally, the thickness map of gas-bearing shale reservoirs in the Longmaxi Formation is obtained by combining the seismic fluid mobility attribute with the inverted velocity data, and two favorable exploration areas are suggested by analyzing the thickness, structure, and burial depth. The present work can not only be used to evaluate shale gas resources in the early stage of exploration, but also help to design the landing point and trajectory of directional drilling in the development stage.


2013 ◽  
Author(s):  
Yvonne Anja Schavemaker ◽  
Mart Zijp ◽  
Jan ter Heege ◽  
Susanne Nelskamp ◽  
Johan Ten Veen

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