The Study Of High Coal Rank Coal Reservoir And Recoverable In Qinshui Basin Heshun Block

The study area is located in the North part of eastern margin of the Qin Shui basin, due to the effect of the multi-period structural superposition in Northern China and multi-period tectonic events, its geological features are complex with a high degree of coal metamorphism.At present,five parameter-wells have been implemented and drilled into drainage,received coal bed gas evaluation parameters, such as coal- bearing property and gas bearing property in the southeast area.The admissibility main coal seam has also been of initial understanding.This article systematically analyses and elaborates the geological conditions of coal-bed methane, characteristics of coal reservoir and admissibility of the geological factors on the basis of systematic collection of past related exploration and research results in the study area and of the researches at home and abroad,through the geological map, outcrop observation and experimental analysis.On the basis of resource calculation and evaluation of coal reservoir, effective and rational deploymen of Coal-bed Methane Wells group are made.The following results are obtained:1.Main objective of the study area No.15 and No.3 coal reservoirs are low ash, high sulfur, high calorific value lean coal and anthracite, thick coal seam, medium depth buried, good gas content, strong adsorption, Lan's pressure also relatively high, but the coal porosity, permeability and gas saturation are relatively low, reservoir pressure of coal is low as well with evident heterogeneity coal reservoir parameters.2.Geological factors affecting on the admissibility of the system are sumarized as two aspects: First, is resource conditions, mainly coal seam thickness, seam gas content, target layer depth; Second, conditions for recovery of coal bed methane, depending on coal permeability, coal reservoir pressure, coal bed methane gas saturation, the desorption and adsorption properties of coal and hydro-geological conditions and coal reservoirs and other aspects can be modified.3.According to the resource calculation combined with coal reservoir evaluation, comprehensive evaluation, No.3 coal-bearing area is about 266.km2, No.15 coal-bearing area is about 1040.40km2. Among them, typeⅠtarget areas are located in the eastern and northern edges, coal-bed gas resource is about 178.72×108m3,Ⅱtype area is about 819.66×108m3.4.Through the study of geological factors on production collected and coal reservoir evaluation, compared to 5 drilled wells, H2 Well optimized production well as exclusive group of the same experiment. Consider the rolls of artificial cracks in the main direction of infiltration, drainage and gas test wells to determine well H2 using five-point type (diamond) well pattern, well away from the gateway for the 300 m×250 m.This thesis further understands reservoir geological conditions, reservoir characteristics and admissibility of the geological factors , it provides scientific basis and an important guiding role in large-scale rationalization and exploration and development of coal bed gas for the next step.