Characteristics and geological significance of fluorescence for sandstone grains and hydrocarbon extracts from low permeability reservoirs in the Ordos Basin, China

With the continuous enhancement of exploration and development in the Ordos Basin, in-depth research has been carried out on the petrological and reservoir characteristics of Chang 2 reservoir in Area A, which provides a geological basis for the efficient development of oil reservoirs. Comprehensive use of reservoir sandstone thin section identification casting analysis, mercury intrusion analysis, logging analysis and other methods to systematically study the petrological characteristics, pore characteristics and reservoir physical properties of Chang 2 reservoir in Area A. The results show that the reservoirs in the study area are dominated by fine-grained sandstones, with low component maturity and high structural maturity. They are all medium-low porosity, low-permeability and ultra-low permeability reservoirs. Primary intergranular pores and residual intergranular pores are developed, the reservoir drainage pressure is low, which is good-medium, and the mercury removal efficiency is high, indicating that the reservoir has good storage performance and seepage properties.

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A case study: evaluating low-porosity and ultra-low-permeability Triassic reservoir rocks in the Ordos Basin by the integration of logs and core

Petroleum Geoscience ◽

10.1144/petgeo2016-146 ◽

2017 ◽

Vol 23 (4) ◽

pp. 454-465 ◽

Cited By ~ 2

Author(s):

Fengqi Tan ◽

Rui Zhao ◽

Yangyang Zhao ◽

Zhejun Pan ◽

Hongqi Li

Keyword(s):

Ordos Basin ◽

Low Permeability ◽

Reservoir Rocks ◽

The Ordos Basin ◽

Low Porosity

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Main Controlled Elements for Accumulation of Ultro-Low Permeability Sandstone Oil Reservoir, Zhenjing Oilfield, Ordas Basin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.868.70 ◽

2013 ◽

Vol 868 ◽

pp. 70-73

Author(s):

Yi Wei Hao ◽

Hai Yan Hu

Keyword(s):

Oil And Gas ◽

Sedimentary Basin ◽

Ordos Basin ◽

Low Permeability ◽

Oil Reservoir ◽

Tight Sandstone ◽

Buoyant Force ◽

Accumulation Mechanism ◽

Oil And Gas Resources ◽

Low Permeability Reservoirs

Ordos Basin is the second largest sedimentary basin in China with very rich oil and gas resources. The exploration targets are typical reservoirs of low permeability. To determine the accumulation mechanism of tight sandstone reservoir, thin section, SEM, numerical calculation were used. The result showed that sandstone should be ultro-low permeability reservoirs with the high content feldspar and lithic arkose or feldspathic litharenite. The reservoir became tight while oil filling, buoyant force is too small to overcome the resistance of capillary force. Therefore, overpressure induced by source rock generation is the accumulation drive force.

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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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.96 ◽

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%.

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Study on the Influential Factors of CO2 Storage in Low Permeability Reservoir

Energies ◽

10.3390/en15010344 ◽

2022 ◽

Vol 15 (1) ◽

pp. 344

Author(s):

Ping Yue ◽

Rujie Zhang ◽

James J. Sheng ◽

Gaoming Yu ◽

Feng Liu

Keyword(s):

Carbon Dioxide ◽

Co2 Storage ◽

Ordos Basin ◽

Influential Factors ◽

Low Permeability ◽

Geological Storage ◽

Co2 Geological Storage ◽

Low Permeability Reservoir ◽

Low Permeability Reservoirs ◽

Breakthrough Pressure

As the demands of tight-oil Enhanced Oil Recovery (EOR) and the controlling of anthropogenic carbon emission have become global challenges, Carbon Capture Utilization and Sequestration (CCUS) has been recognized as an effective solution to resolve both needs. However, the influential factors of carbon dioxide (CO2) geological storage in low permeability reservoirs have not been fully studied. Based on core samples from the Huang-3 area of the Ordos Basin, the feasibility and influential factors of geological CO2 sequestration in the Huang-3 area are analyzed through caprock breakthrough tests and a CO2 storage factor experiment. The results indicate that capillary trapping is the key mechanism of the sealing effect by the caprock. With the increase of caprock permeability, the breakthrough pressure and pressure difference decreased rapidly. A good exponential relationship between caprock breakthrough pressure and permeability can be summarized. The minimum breakthrough pressure of CO2 in the caprock of the Huang-3 area is 22 MPa, and the breakthrough pressure gradient is greater than 100 MPa/m. Huang-3 area is suitable for the geological sequestration of CO2, and the risk of CO2 breakthrough in the caprock is small. At the same storage percentage, the recovery factor of crude oil in larger permeability core is higher, and the storage percentage decreases with the increase of recovery factor. It turned out that a low permeability reservoir is easier to store CO2, and the storage percentage of carbon dioxide in the miscible phase is greater than that in the immiscible phase. This study can provide empirical reference for caprock selection and safety evaluation of CO2 geological storage in low permeability reservoirs within Ordos Basin.

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