Fractured tight sandstone oil and gas reservoirs: A new play type in the Dongpu depression, Bohai Bay Basin, China

AAPG Bulletin ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 363-377 ◽  
Author(s):  
Lianbo Zeng ◽  
Hui Su ◽  
Xiaomei Tang ◽  
Yongmin Peng ◽  
Lei Gong
Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6991
Author(s):  
Zehou Xiang ◽  
Kesai Li ◽  
Hucheng Deng ◽  
Yan Liu ◽  
Jianhua He ◽  
...  

Tight sandstone oil and gas reservoirs are widely distributed, rich in resources, with a bright prospect for exploration and development in China. Due to multiple evolutions of the structure and sedimentary system, the gas–water distribution laws are complicated in tight sandstone gas reservoirs in the northern Ordos area. It is difficult to identify gas and water layers in the study area. In addition, in the development and production, various factors, such as the failure of the instrument, the difference in construction parameters (injected sand volume, flowback rate), poor test results, and multi-layer joint testing lead to unreliable gas test results. Then, the inaccurate logging responses will be screened by unreliable gas test results for different types of fluids. It is hard to make high-precision fluid logging identification charts or models. Therefore, this article combines gas logging, well logging, testing and other data to research the test and logging data quality classification. Firstly, we select reliable standard samples through the initial gas test results. Secondly, we analyze the four main factors which affect the inaccuracy of gas test results. Thirdly, according to these factors, the flowback rate and the sand volume are determined as the main parameters. Then, we establish a recognition chart of injected sand volume/gas–water ratio. Finally, we proposed an evaluation method for testing quality classification. It provides a test basis for the subsequent identification of gas and water through the second logging interpretation. It also provides a theoretical basis for the exploration and evaluation of tight oil and gas reservoirs.


2021 ◽  
Author(s):  
Sian Zhu ◽  
Hongtao Chen ◽  
Yongjun Hu ◽  
Feng Yang ◽  
Yubin Feng

Abstract The genetic mechanism of shallow gas reservoirs is complex, which is usually characterized by shallow burial depth, multiple types, low reserves and wide distribution, so that the inversion based on P-wave data alone may be ambiguous. For shallow reservoir with large lateral variation, it is hard to accurately predict oil and water distribution by conventional P-wave prestack inversion. Marine four-component (M4C) P-wave and S-wave joint inversion can solve the problem effectively. M4C seismic survey collects P-wave and S-wave seismic data. An initial model can be established based on fine structural interpretation of P-wave and S-wave data and S-wave compression pattern matching. It lays a good foundation for subsequent P-wave and S-wave joint inversion. Based on the P-wave seismic record equation proposed by Fatti et al., a seismic record equation from poststack P-wave and S-wave joint inversion was derived according to the relationship among reflection coefficient, P-wave impedance, S-wave impedance and density, then important lithologic parameters (P-wave impedance, S-wave impedance and density) were calculated, and finally the ratio of P-wave velocity to S-wave velocity which is more sensitive to oil and gas was obtained. According to the ratio of P-wave velocity to S-wave velocity, the oil and gas distribution was predicted in shallow Bohai Bay Basin. Application has proven that the inversion can well reflect the fluid distribution, and the coincidence between the inversion results and the drilling data is up to 85%.M4C seismic survey was conducted for the first time to the shallow oil and gas reservoirs with rapid lateral variation in the Bohai Bay Basin, and collected raw P-wave and S-wave seismic data. Based on the data, the precision and reliability of P-wave and S-wave joint inversion was improved. The results provided strong technical support to the reserves and production increase in the Bohai Bay Basin.


Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1122
Author(s):  
Enli Wang ◽  
Junduo Zhang ◽  
Guoliang Yan ◽  
Qing Yang ◽  
Wanjin Zhao ◽  
...  

Fault detection is important to seismic interpretation, especially for tight oil and gas reservoirs. Generally speaking, large-scale faults can be accurately imaged and are easy to detect by conventional methods, but the concealed ones in low-amplitude structural regions are difficult to find. In these areas, the scale and displacement of concealed faults are usually very small. Due to the good uniform and weak amplitude disturbances in the seismic events, the traditional discontinuity attributes extracted from seismic data are always not effective. This is because the discontinuous features of large faults are very significant, and the weak anomalies caused by hidden faults are very close to the continuous background. This paper takes a tight sandstone reservoir in the Ordos Basin of China as an example to explore the detection method of subtle faults in low-amplitude structural areas. With the phase congruency analysis method, we extract edge features from the post-stack coherence attributes to identify hidden faults. Practice shows that this idea has outstanding performance in mining hidden fracture features and improving the accuracy of fracture recognition. The results successfully predict a shear fault zone in the northeast of the work area, find a new fracture zone in the center of the survey and a series of hidden faults in non-target strata. It would be beneficial to extend the strata and area of oil and gas reservoirs.


ACS Omega ◽  
2021 ◽  
Author(s):  
Donglin Zhang ◽  
Youjun Tang ◽  
Hongbo Li ◽  
Tianwu Xu ◽  
Yunxian Zhang ◽  
...  

2018 ◽  
Vol 36 (5) ◽  
pp. 1229-1244
Author(s):  
Xiao-Rong Qu ◽  
Yan-Ming Zhu ◽  
Wu Li ◽  
Xin Tang ◽  
Han Zhang

The Huanghua Depression is located in the north-centre of Bohai Bay Basin, which is a rift basin developed in the Mesozoic over the basement of the Huabei Platform, China. Permo-Carboniferous source rocks were formed in the Huanghua Depression, which has experienced multiple complicated tectonic alterations with inhomogeneous uplift, deformation, buried depth and magma effect. As a result, the hydrocarbon generation evolution of Permo-Carboniferous source rocks was characterized by discontinuity and grading. On the basis of a detailed study on tectonic-burial history, the paper worked on the burial history, heating history and hydrocarbon generation history of Permo-Carboniferous source rocks in the Huanghua Depression combined with apatite fission track testing and fluid inclusion analyses using the EASY% Ro numerical simulation. The results revealed that their maturity evolved in stages with multiple hydrocarbon generations. In this paper, we clarified the tectonic episode, the strength of hydrocarbon generation and the time–spatial distribution of hydrocarbon regeneration. Finally, an important conclusion was made that the hydrocarbon regeneration of Permo-Carboniferous source rocks occurred in the Late Cenozoic and the subordinate depressions were brought forward as advantage zones for the depth exploration of Permo-Carboniferous oil and gas in the middle-northern part of the Huanghua Depression, Bohai Bay Basin, China.


2015 ◽  
Vol 75 (11) ◽  
Author(s):  
Mostafa Alizadeh ◽  
Zohreh Movahed ◽  
Radzuan Junin ◽  
Rahmat Mohsin ◽  
Mehdi Alizadeh ◽  
...  

The purpose of modelling the fractures is to create simulation properties with the power to predict the reservoir behaviour. Petrel software is one of the best softwares in the market that can do this task very well, but there is no available educational paper for every researcher. Therefore, in this work, a fracture modelling job was done in one of the most important Iranian fields using Petrel software and image log data. The purpose of this work was  to determine the new information of the fractures in Gachsaran field and also to prepare a valuable educational paper for other researchers who are interested to learn about the fracture modelling. This work revealed that in this field, the longitudinal fractures had been parallel to minimum stress (Zagros trend), fracture intensity was the nearest to the major fault and northern flank, fracture porosity was 0-7%, fracture permeability was 0-6000 MD, and more valuable information is provided in this paper.


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