Conclusion The efficient identification of eroded channel-vale of weathering crust in Ordovician and top fluctuant configuration of the reservoir created a firm foundation for prediction of O_1m5_(1+2) reservoir thickness,physical and gas-bearing properties,and provided decision-making proofs for development and well position optimization.
The exploration and production of the shallow-middle gas reservoirs in the study area show that seismic exploration plays an important role in delineation of reservoir distribution,description of the spatial geometry of the reservoirs,inverse modeling of the reservoir parameters,study of sedimentary facies and heterogeneity,determining prolific gas-bearing zone,and recognition of gas-bearing properties.
By using qualitative and quantitative analysis,the influence of the factors on gas-bearing properties,such as,burial depth and thickness of coal seams,lithology of roof and floor rocks,and geology structures has been discussed.
On the basis of detailed introduction to the appraisal methods, a prognosis has been made on the gas bearing capacity of deep seated coal beds in the Huainan and Huaibei areas by use of gas bearing gradient method with local geological conditions being taken into consideration. The prognosis result provides data for mass development of coal bed gas in the areas.
Methods Sixty - eight cases of broin mass were confirmed by pathology, and their ultrasonographic findings were categorized as following: cystic (type Ⅰ), cystic and solid (type Ⅱ), solid (type Ⅲ), and air - containing (type Ⅳ).
The results indicate that the mutual confirmations among multiple predictions can eliminate the multi-solutions from single geophysical techniques and improve reservoir prediction and hydrocarbon detection.