Chlorite coatings of quartz grains and the implications for Permian gas reservoirs in the Ordos Basin (China)

2022 ◽  
pp. 171-177
Author(s):  
Aiping Fan ◽  
Jinbu Li ◽  
Zhongjun Zhao ◽  
A.J. (Tom) van Loon
Keyword(s):  
Ordos Basin ◽  
Gas Reservoirs ◽  
The Ordos Basin ◽  
Quartz Grains

scholarly journals Analysis of the charging process of the lacustrine tight oil reservoir in the Triassic Chang 6 Member in the southwest Ordos Basin, China

2017 ◽  
Vol 54 (12) ◽  
pp. 1228-1247
Author(s):  
Zhengjian Xu ◽  
Luofu Liu ◽  
Tieguan Wang ◽  
Kangjun Wu ◽  
Wenchao Dou ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Source Rocks ◽  
Driving Mechanism ◽  
Tight Oil ◽  
Geological Time ◽  
Tight Sandstone ◽  
Main Production ◽  
The Ordos Basin ◽  
Homogenization Temperatures ◽  
Quartz Grains

With the success of Bakken tight oil (tight sandstone oil and shale oil) and Eagle Ford tight oil in North America, tight oil has become a research focus in petroleum geology. In China, tight oil reservoirs are predominantly distributed in lacustrine basins. The Triassic Chang 6 Member is the main production layer of tight oil in the Ordos Basin, in which the episodes, timing, and drive of tight oil charging have been analyzed through the petrography, fluorescence microspectrometry, microthermometry, and trapping pressure simulations of fluid inclusions in the reservoir beds. Several conclusions have been reached in this paper. First, aqueous inclusions with five peaks of homogenization temperatures and oil inclusions with three peaks of homogenization temperatures occurred in the Chang 6 reservoir beds. The oil inclusions are mostly distributed in fractures that cut across and occur within the quartz grains, in the quartz overgrowth and calcite cements, and the fractures that occur within the feldspar grains, with blue–green, green, and yellow–green fluorescence colours. Second, the peak wavelength, Q650/500, and QF535 of the fluorescence microspectrometry indicate three charging episodes of tight oil with different oil maturities. The charging timings (141–136, 126–118, and 112–103 Ma) have been ascertained by projecting the homogenization temperatures of aqueous inclusions onto the geological time axis. Third, excess-pressure differences up to 10 MPa between the Chang 7 source rocks and the Chang 6 reservoir beds were the main driving mechanism supporting the process of nonbuoyancy migration.

Logging Identification Technology of Sedimentary Facies and Gas Layers within Low Pressure, Low Permeability and Low Abundance Gas Reservoirs: Example from SQW Block of the Sulige Gas Field, Ordos Basin, China

2012 ◽  
Vol 616-618 ◽  
pp. 96-99
Author(s):  
Fang Lu ◽  
Xin Jiang Du ◽  
Zhi Jun Mao ◽  
Yan Zhou ◽  
Yue Bin Cui ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Sedimentary Facies ◽  
Low Pressure ◽  
Low Permeability ◽  
Braided River ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Exploration Target ◽  
The Ordos Basin ◽  
Gas Potential

Sulige Gas Field is located in the Suligemiao area, northwest of the Ordos Basin, with a prospecting area of about 4×104km2. Owing to the strong heterogeneity in the SQW Block, one of exploration blocks in the Sulige Gas Field, remains reservoir characteristics of the gas field: lithologic gas reservoirs with characteristics of “three low” (low pressure, low permeability and low abundance). The He8 member of the Shihezi formation, the major exploration target, is deposited in braided river environment. The conventional logging data is very useful to indentify different facies and to estimate gas potential. The technology of discrimination with sedimentary facies and gas layers using logging data is established in this paper. We use the technology combining with AVO and other exploration methods to pick out 4 favorable exploration target areas with the success rate of more than 80%.

scholarly journals Detection of gas reservoirs by the joint use of P- and PS-waves: A case study on the Ordos basin, China

2009 ◽  
Vol 22 (3) ◽  
pp. 307-313
Author(s):  
Xiucheng Wei ◽  
Xiangyang Li ◽  
Yang Liu ◽  
Songqun Shi ◽  
Weidong Jiang
Keyword(s):  
Ordos Basin ◽  
Gas Reservoirs ◽  
The Ordos Basin

scholarly journals A novel productivity evaluation approach based on the morphological analysis and fuzzy mathematics: insights from the tight sandstone gas reservoir in the Ordos Basin, China

2019 ◽  
Vol 10 (4) ◽  
pp. 1263-1275
Author(s):  
Shanyong Liu ◽  
Gongyang Chen ◽  
Yishan Lou ◽  
Liang Zhu ◽  
Daoyao Ge
Keyword(s):  
Ordos Basin ◽  
Gas Content ◽  
Practical Significance ◽  
Fuzzy Mathematics ◽  
Tight Gas ◽  
Test Results ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs ◽  
Morphological Theory ◽  
The Ordos Basin

AbstractTight gas reservoirs have rich potential resources, which are hot spots in unconventional oil and gas exploration and development. Due to their strong heterogeneity and complex pore structures, the conventional approaches of productivity evaluation always have difficulty in predicting the gas content. This study aims to devise a new method to interpret the productivity of LX Block in the Ordos Basin using the morphological theory and fuzzy mathematics. First, core test results were used to investigate the reservoir quality and physical properties. Then, the change law of gas content was defined by the morphological theory of logging and mud logging curves. Assignments of those factors that affected the final production were provided based on fuzzy mathematics. Finally, the prediction model of productivity was established. The results show that the lower limit of the reservoir thickness in the LX Block is 3.1 m, whereas the porosity and permeability are 5% and 0.15 × 10−3 μm2, respectively. The morphological characteristic of the gas logging curve for those layers with high potential production normally presents a box shape with a high relative number of serration. The reservoir in the studied area can be classified into four categories according to the relationship between the logging curve shape and daily production, and each category is automatically identified. The coincidence rate between the prediction results and the gas test results is 84.1%, which satisfies the demand on the field. The findings have important theoretical and practical significance for screening the location of fracturing spots and predicting the production of tight gas reservoirs.

scholarly journals A new multi-disciplinary integrated steering technology for horizontal wells in tight sandstone gas reservoirs: A case study of the Ordos Basin

2020 ◽  
Vol 7 (4) ◽  
pp. 328-336
Author(s):  
Shixiang Fei ◽  
Yubin Du ◽  
Yijun Wang ◽  
Nan Chen ◽  
Yang Gao ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Horizontal Wells ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
The Ordos Basin

scholarly journals Control of differential diagenesis of tight sandstone reservoirs on the gas–water distribution: A case study on the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin

2021 ◽  
pp. 014459872110345
Author(s):  
Xinshe Liu ◽  
Xing Pan ◽  
Huitao Zhao ◽  
Zhenliang Wang ◽  
Peilong Meng ◽  
...  
Keyword(s):  
Water Distribution ◽  
Ordos Basin ◽  
Gas Reservoirs ◽  
Reservoir Heterogeneity ◽  
Upper Paleozoic ◽  
Medium Strength ◽  
Porosity And Permeability ◽  
Differential Diagenesis ◽  
The Ordos Basin ◽  
Diagenetic Facies

The sandstone reservoirs in the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin are vastly different and feature particularly complex gas–water distributions. Scanning electron microscopy, fluorescence, Raman spectroscopy inclusions, relative permeability analysis, and nuclear magnetic resonance were utilized in this study based on core data, identification statistics, and various thin-section microscope measurements. Samples from the Upper Paleozoic He 8 Member in the northern Tianhuan depression were collected to study the characteristics of reservoir heterogeneity and gas–water distribution, which were controlled by differential diagenesis. The results indicate that compaction and dissolution are the two most important factors controlling reservoir heterogeneity. Large differences in diagenesis–accumulation sequences and pore structure characteristics affect reservoir wettability, irreducible water saturation, and gas displacement efficiency, thereby controlling the gas–water distribution. The He 8 Member is a gas reservoir that is densified because of accumulation. Reservoirs can be divided into three types based on the relationship between diagenetic facies and gas–water distribution. Type I is characterized by weak compaction, precipitate or altered kaolinite cementation, strong dissolution of diagenetic facies, and high porosity and permeability. This type is dominated by grain-mold pores and intergranular dissolution pores and produces gas reservoirs with high gas yield. Type II is characterized by medium-strength compaction, altered kaolinite or chlorite cementation, weak dissolution of diagenetic facies, and medium porosity and permeability. This type is dominated by residual intergranular pores, a few residual intergranular pores, and dispersed dissolution pores, producing gas reservoirs with low gas yield. Type III is characterized by medium-strength compaction, altered kaolinite cementation, and medium-strength dissolution of diagenetic facies. This type is dominated by kaolinite intercrystal pores and dispersed dissolution pores, producing gas reservoirs with high water yield.

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