| Sanbei yangchang-Kucaowa mining area belongs to Zhuozishan coalfield,which is located in the thrust belt of the western margin of ordos basin.The main coal-bearing strata are upper carboniferous taiyuan formation(C2t)and lower Permian shanxi formation(P1s).Overall is an anticlinal structure,the axial near the north and south,east wing structure is complex,the west wing dip in more than 25°,more development and thrust fault.In this paper,through a comprehensive system to collect three norths sheep farm-bitter herb depression mining geological data,such as the regional geology,coal field exploration and related research results,on the basis of the three north sheep farm-bitter herb depression mining coal-bed methane resources occurrence conditions of system analysis,and the further study of existing geological data,through data processing,field geological investigation,methods of preparation of thematic maps,summarize in the coal reservoir geological characteristics and physical property characteristics;The formation and distribution of coalbed methane(CBM)in sanbei yangchang-kukaowa area and the conditions of reservoir formation were studied in depth,the potential of CBM exploration and development in the investigated area was evaluated,and the favorable zones for CBM occurrence were delineated.The main coal-bearing strata in the Sanbei yangchang-Kucaowa mining area are carboniferous Permian shanxi formation and taiyuan formation.The average thickness of 9coals is 7.23m.16.The average thickness of coal is 4.23m;The accumulated thickness of the main minable coal seam is generally greater than 10m.The degree of metamorphism of coal is relatively high,and the coal is mainly 1/3 coking coal and gas coal.9.Buried depth of coal:804.71-1483.54m;16 the buried depth of coal is 905.65--1510.89m.The top and bottom mudstone is mainly mudstone,sandy mudstone and thick.The coalbed methane reservoir of shanxi formation in the study area is mainly composed of 9 coals,and the coalbed methane reservoir of taiyuan formation is mainly composed of 16 coals.The maximum reflectance of vitrinite in coal seam ranges from 0.5%to 1.2%,with an average of 0.8%.The metamorphism degree is determined to be stage II of bituminous coal,namely,gas coal stage.Gas measurement data of qishen well 1 near the study area showed that the total hydrocarbon anomaly in coal seam was relatively high,with the highest value of total hydrocarbon anomaly in shanxi group reaching 3.67%and that in taiyuan group reaching 5.54%.The gas content data of qishen well 1 showed that the gas content of 9 coal was 3.48m3/t,and the gas content of 16 coal was 6.38m3/t?9.75m3/t,with an average of 7.88m3/t,indicating that the gas content of this area was relatively good.Contains 9 coal in the study area and the two main purposes of 16 coal seam,through to the coal seam portfolio analysis of the evaluation results of single purpose,take the scope of their respective areas of overlap completely as the target area of coal bed methane(CBM),completely overlapping areas favorable as the target area of coal bed methane(CBM),the range of vision zone completely overlapping areas favorable for coalbed methane and the range of time vision area completely overlapping range as the CBM vision area,eventually determine the whole prospect areas in the study area,favorable area,target area and the target area.According to this standard,the target area of CBM was finally determined to be located in the northern area of kukaowa with an area of 40.80 km2.To sum up,the complex structure in the study area,the buried depth of coal seam is relatively great,big coal thickness,coal bed methane occurrence condition is good,kind is given priority to with gas coal and 1/3 coking coal,coal pore fracture,permeability medium,organic maceral components of coal and rock is given priority to with vitrinite,hydrocarbon generation ability,high hydrocarbon content,are concentration of cultural resources,has great coal-bed methane resources exploration and development potential. |
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