scholarly journals Geological Factors and Reservoir Properties Affecting the Gas Content of Coal Seams in the Gujiao Area, Northwest Qinshui Basin, China

Energies ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 1044 ◽  
Author(s):  
Zhuo Zou ◽  
Dameng Liu ◽  
Yidong Cai ◽  
Yingjin Wang ◽  
Jiapeng Li
Keyword(s):  
Gas Content ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Qinshui Basin ◽  
Geological Factors

scholarly journals Study on Reservoir Properties and Critical Depth in Deep Coal Seams in Qinshui Basin, China

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Guiqiang Zheng ◽  
Bin Sun ◽  
Dawei Lv ◽  
Zhejun Pan ◽  
Huiqing Lian
Keyword(s):  
Coal Seam ◽  
Step Change ◽  
Gas Content ◽  
Burial Depth ◽  
Critical Depth ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Qinshui Basin ◽  
Geological Conditions ◽  
Change Characteristics

Coalbed methane (CBM) reservoir properties and relationship of properties with burial depth were studied based on the data derived from 204 deep CBM production wells in Qinshui Basin, China. Through the study, it is found that permeability and porosity decrease with the increase of burial depth and the decreasing trend shows step-change characteristics at a critical burial depth. They also show divisional characteristics at certain burial depth. Gas content, geostress, and geotemperature increase with the increase of burial depth, and the increasing trend shows step-change characteristics and also have divisional characteristics at certain burial depth. Based on the previous study on the reservoir property changes with burial depth, three series of critical depth using different parameters are obtained through simulating the critical depth using the BP neural network method. It is found that the critical depth is different when using different parameters. Combined the previous study with the normalization of three different parameter types, the critical depth in Qinshui Basin was defined as shallow coal seam is lower than 650 m and transition band is 650–1000 m, while deep coal seam is deeper than 1000 m. In deep coal seams, the geological conditions and recovery becomes poor, so it can be defined as unfavorable zones. Therefore, other development means, for example, CO2 injection, need to be used to accelerate the deep coal methane development.

scholarly journals Vertical and lateral variation of gas content associated with coal seams

2015 ◽  
pp. 49-59
Author(s):  
Luis D. Caro ◽  
Astrid Blandón ◽  
Jorge M. Molina
Keyword(s):  
Coal Seam ◽  
Bituminous Coal ◽  
Direct Relationship ◽  
Vitrinite Reflectance ◽  
Gas Content ◽  
Lateral Variation ◽  
Coal Seams ◽  
Content Variation ◽  
Geological Factors ◽  
Proximal Analysis

Vertical and lateral gas content variation associated within a coal seam and its relation to porosity and geology was researched. Several seams of high sub-bituminous and bituminous coal volatile C from Amaga formation were selected. Channel samples were taken and were subdivided into the different plies (lithotypes associations), performing proximal analysis; Petrographic (maceral counting and determining the vitrinite reflectance); furthermore desorption testing and porosity.The higher gas content was in intermediate plies. It was possible to identify that the gas content, and micropores and mesopores has a direct relationship; also, there is a direct relationship between the content of liptinites macerals and gas content. In some cases, these relationships were not clear, since there is influence of geological factors such as the presence of faults favor migration and degassing of the mantles studied.

scholarly journals Productivity subarea of CBM field and its key controlling factors: A case study in the Hancheng pilot test area, southeastern Ordos Basin, China

2018 ◽  
Vol 37 (1) ◽  
pp. 102-124 ◽  
Author(s):  
Yanfei Liu ◽  
Dazhen Tang ◽  
Song Li ◽  
Hao Xu ◽  
Shu Tao ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Ordos Basin ◽  
Gas Production ◽  
Test Area ◽  
Gas Content ◽  
Pilot Test ◽  
Coal Seams ◽  
Geological Factors ◽  
Drop Rate

The Hancheng block in the southeastern Ordos Basin is one of the earliest and the most important areas for coalbed methane exploration and development in China. However, there are significant production variations in different wells or even some adjacent wells in the Hancheng block. To reveal the reasons of production differences in such a small scale, further detailed studies of coalbed methane productivity in the Hancheng pilot test area, a precursor trial area in Hancheng block with mature, well-characterized coalbed methane reservoirs and long-term production database, were conducted. The influence of nine factors (including engineering and geological factors) on gas production was analyzed. By introducing the rough set theory, which is applicable to the vague, imprecise, and incomplete information system, this paper presents a method for quantitative evaluation of the influencing factors on gas production. The results indicate that there are certain distribution characteristics of productivity in Hancheng pilot test area, which can be partitioned into four zones. The degressive order of the influencing degree of these nine factors is (i) the distance between the well and the fault, (ii) the structure curvature of the coal seams, (iii) the gas content, (iv) the critical reservoir ratio, (v) the volume of the fracturing liquids per meter, (vi) the volume of the fracturing sand per meter, (vii) the dynamic liquid level drop rate, (viii) the depth, and (ix) the thickness. Geological factors, especially the influence of fault, structural curvature of the coal seams and gas content, play a major role in controlling long-term gas production. Engineering factors (effect of fracturing and dynamic liquid level drop rate) have always been integral parts of coalbed methane development.

Technologies extraction of coalbed methane in the Qinshui basin of China

2018 ◽  
pp. 102-108
Author(s):  
Lu Yanjun ◽  
Han Jinxuan ◽  
V. V. Shelepov ◽  
E. Yu. Makarova ◽  
Li Kai ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Electric Pulse ◽  
Gas Content ◽  
Low Permeability ◽  
Reservoir Pressure ◽  
Vertical Wells ◽  
Coal Seams ◽  
Qinshui Basin ◽  
Multi Stage ◽  
Total Resource

Coalbed methane (CBM) is a new clean and unconventional energy that has broad space for development. In Qinshui basin, CBM reserves reach 3,97·1012m3, which is 10,8% of the total resource in China. Compared to the main coal basins of USA, Australia, Canada and Russia, coal seams in Qinshui basin have the characteristics of high metamorphism, high gas content, low porosity, low permeability and low reservoir pressure. Therefore, effective stimulation treatments must be used in Qinshui basin to realize industrial exploitation of CBM. At present, vertical wells with hydraulic fracturing are dominated in Qinshui basin. In addition, injection CO2, electric pulse, multi-stage fracturing and other technologies are also applied to the CBM exploitation.

Comparative geological setting of conventional oil and gas fields and CSG resources in the Surat/Bowen Basin, Queensland

2009 ◽  
Vol 49 (2) ◽  
pp. 580
Author(s):  
Rob Willink
Keyword(s):  
Oil And Gas ◽  
Gas Content ◽  
Small Contribution ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Oil And Gas Fields ◽  
The Difference ◽  
Permian Coal ◽  
Gas Fields ◽  
Coal Measures

The Surat/Bowen Basin has long been of interest to explorers in pursuit of gas and oil in conventional reservoirs. Some 500 BCF of gas and 32 million barrels of oil have been produced from sandstones of Permian, Triassic and Jurassic age. Geochemical evidence suggests that these hydrocarbons were sourced almost exclusively from Permian coal measures, though a small contribution from Triassic coals cannot be discounted. Primary interest in these basins today, however, resides in the exploration for, and commercialisation of, methane trapped in coal seams within the Permian and Jurassic successions. Total industry declared proven, probable and possible (3P) coal seam gas (CSG) reserves exceed 30 TCF, of which some 8 TCF are attributed to reserves in Permian coal seams, and 22 TCF in Jurassic coal seams. With particular reference to a representative regional seismic traverse through the basin, this presentation will explain why known conventional and CSG fields in these basins are located where they are from a regional structural and stratigraphic perspective. The difference between the reservoir properties of coals and sandstones, and between the Permian and Jurassic coals will be discussed in terms of their maceral composition, gas content, adsorption capacity and thermal maturity. In addition, the location of known sweetspots within CSG fairways will be revealed. The presentation will conclude with some speculative comments on what the future holds for both conventional and CSG exploration in these basins and will show that Origin Energy, in particular through its investment with Conoco Phillips in Australian Pacific LNG (APLNG), is well placed to participate in that future.

Comprehensive Analysis of Factors Affecting Coalbed Methane Productivity: A Case Study of Southern Qinshui Basin

2014 ◽  
Vol 962-965 ◽  
pp. 21-28
Author(s):  
Bei Liu ◽  
Wei Hua Ao ◽  
Wen Hui Huang ◽  
Qi Lu Xu ◽  
Juan Teng
Keyword(s):  
Coalbed Methane ◽  
Gas Production ◽  
Gas Content ◽  
Burial Depth ◽  
Reservoir Pressure ◽  
Factors Affecting ◽  
Qinshui Basin ◽  
Geological Conditions ◽  
Geological Factors ◽  
Southern Qinshui Basin

Coalbed methane (CBM) productivity is influenced by various factors. Based on field production data and test data of southern Qinshui Basin, factors including geological factors, engineering factors and drainage factors that affect CBM productivity are analyzed. Analytic hierarchy process (AHP) is introduced to calculate the contribution of each parameter to CBM productivity. A three-level model for evaluating CBM productivity based on AHP is established. The results show that average daily gas production of single well in southern Qinshui Basin increases with gas content, coal seam thickness, permeability, porosity, gas saturation, critical desorption pressure. Filling minerals in pores and fractures of coal can decrease gas content, porosity and permeability of coal reservoir. When burial depth is deeper than 500m or reservoir pressure is greater than 2MPa and burial depth is shallower than 1000m or reservoir pressure is less than 10MPa, CBM productivity is relatively high. According to the calculation, the weight of geological factors, engineering factors and drainage factors are 50%, 25% and 25%, respectively. Reservoir physical properties, geological conditions, fracturing technology and drainage process have the most impact, the weight of which are 33.33%, 16.67%, 11.79%, and 15.00%, respectively.

A comprehensive analysis of conditions and features of oil-and-gas content within the Akhlovskaya structural zone (the North Caucasus)

2021 ◽  
pp. 25-38
Author(s):  
I. I. Bosikov ◽  
A. I. Mazko ◽  
A. V. Mayer ◽  
O. V. Gagarina
Keyword(s):  
Oil And Gas ◽  
Gas Content ◽  
North Caucasus ◽  
Reservoir Properties ◽  
Resource Base ◽  
Entire Area ◽  
The North ◽  
Urgent Task ◽  
Porosity Coefficient ◽  
Saturated Thickness

At the present stage, the development of the oil industry of the Russian Federation is impossible without replenishing the resource base, and therefore an urgent task is to analyze and assess the conditions and characteristics of oil-andgas content in unexplored regions.Purpose of the study is an analysis and an assessment of reservoir properties of rocks of the Aptian horizon Р1+2- К2 within the Akhlovskaya structure.We analyzed the graphs of the distribution of indicators in wells R-212 and R-213 in the Akhlovsky area and concluded that the reservoir is heterogeneous, and there are interlayers of mudstones with other reservoir properties and geophysical characteristics. The following pairs of parameters (porosity coefficient and oil-saturated thickness of rocks, rock resistivity and porosity coefficient, rock resistivity and oil-saturated thickness of rocks) have a significant positive correlation. Having studied the distribution of indicators in the Akhlovsky area for wells R-212 and R-213 along one horizon, we concluded that these indicators differ very slightly, which indicates the homogeneity of the reservoir properties. Qualitative indicators Qualitative indicators don't change. Thus, we can expect similar indicators within the entire area of the explored layer Р1+2- К2 in the territory of the Akhlovsky area.

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