3 edition of Measuring formation pressures and the degree of gas drainage in a large coalbed gas drainage field found in the catalog.
Bibliography: p. 15.
|Statement||U.S. Dept. of the Interior, Bureau of Mines|
|Publishers||U.S. Dept. of the Interior, Bureau of Mines|
|The Physical Object|
|Pagination||xvi, 138 p. :|
|Number of Pages||79|
|3||Report of investigations (United States. Bureau of Mines) ;|
nodata File Size: 3MB.
CBM and CO 2-ECBM related sorption processes in coal, a review. Based on the results of test wells case verification, the optimized production strategies should be adopted in the CBM production process to ensure production wells produce efficiently.
Otherwise, coal reservoirs are not only damaged by a stress-sensitive effect, but also blocked by the coupled relationship between gas and water, resulting in insufficient pressure propagation.and its average pressure is further described by Eq. During CBM development, the coal reservoir is damaged by the effective stress effect, with recovery occurring due to the matrix shrinkage effect and the slippage effect. Methane forms inside coal beds according to geological conditions through coalification.
We combine material balance and production equations, and then apply the dimensionless water production index. In addition, although the actual cumulative gas production is greater in the early stage, optimized cumulative gas production exceeds the actual value after 700 days of production Fig. 13a and bthe average desorption rate of tectonic coal is much larger than that of intact coal under the same pressure, indicating the initial rapid desorption capacity.
3986 Sample 4 Water 1 0. Gas outburst disasters and the mining technology of key protective seam in coal seam group in the Huainan coalfield. The combination of pressure and gas content data has also allowed an in situ isotherm curve, relating the formation pressure to adsorbed gas content, to be developed for the area of the production wells. It was found that vitrinite levels in Tabas and Shahrood mines coal were 81. A principle for BHFP and gas production control is proposed and a mathematical model for the optimization of drainage strategies is established, which are then applied to CBM wells in the Shizhuangnan Block China to verify the applicability of this method.
The comparable roof refractions from the monitored seismogram and CT-inverted velocity distributions demonstrate that changes in the coalbed roof during the gas drainage are minor. Otherwise, a rapid drop in BHFP or a rapid increase in gas production can cause a decrease in reservoir permeability and inhibit expansion of the desorption radius, resulting in inefficient depressurization and low gas production in CBM wells.
However, these optimal strategies are essentially qualitative or semi-quantitative. A parametric study of the effects of coal seam properties on gas drainage efficiency. 3 Well HC01 997 148. International Journal of Rock Mechanics and Mining Sciences, 71, 105—116. Accordingly, test data are analyzed with the water well test analysis method. This has been illuminated in some Chinese and foreign literatures.
" Journal of Coal Science and Engineering China 16.
This exponent is necessary to account for the deliverability, heterogeneity, and well-spacing, among other factors that affect the gas recovery [ 43].
Average desorption rate of tectonic and intact coals at different times.