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Marine shale reservoirs have experienced intense tectonic movements in southeastern Chongqing, resulting in widely developed folds, faults and bedding slip deformation. The gas content is of a wide range while the organic matter content and thickness are sufficient for shale gas accumulation. Here, we review previous work and present outcrop and core data from 11 shale wells around southeastern Chongqing to analyze and summarize tectonic types and their combinations, as well as their influence on shale gas preservation and enrichment. Fault and bedding slips are prevalent in shale reservoirs, and they apparently influence shale gas content. Bedding slip crush is usually formed at the bottom interval where the total organic content is high from intense horizontal compression. Bedding slip crushing and well-developed high-angle natural fractures form a net fracture system where shale gas is enriched in an anticline structure or lost to air in a syncline structure laterally. Strata dip is the key geological factor that controls bedding slip deformation in shale reservoirs in certain areas. According to the established bedding slip geological model, when bedding slip occurred, the critical strata dips of the lower Silurian Longmaxi Formation were 13.34°, respectively. Bedding slip crushed anticlines without faults and synclines without faults and bedding slip crushing are the two tectonic patterns that are favorable for shale gas preservation and enrichment, which should be the focus of further explorations of lower Paleozoic shale gas in southeastern Chongqing.

The adsorption/desorption characteristics of a coal reservoir play an important role in coalbed methane (CBM) development. The proximate analysis, maceral analysis and methane isothermal adsorption/desorption experiment are carried out based on coal samples from no. 4+5 coal seam in Baode block. Combing with coal experimental data and the CBM well-produced water salinity data in the Baode block, the effect of salinity and water content on CBM adsorption/desorption characteristics of the coal reservoir and its influencing mechanism is discussed. The results show that the CBM adsorption and desorption capacity decreases with the increase of water salinity and the decrease value shows a decreasing trend. The increase of water salinity reduces the solubility of methane in coal seam water and then reduces the adsorption capacity of methane. With the increase of water content, the adsorption and desorption capacities of CBM decrease gradually. The CBM adsorption and desorption capacities decrease with the increase of water content in coal samples. The adsorption/desorption capacities of coal samples change rapidly in the low-water content stage and slowly in the high-water content stage. The competitive adsorption effect and water blocking effect between water and methane molecules are the main influencing mechanisms of water content on CBM adsorption/desorption. It can be seen that the salinity and water content will have a certain adverse impact on the adsorption and desorption capacity of CBM in the Baode block. The influence of the difference in water content and salinity in the coal seam cannot be ignored in reserve evaluation and productivity prediction of CBM. The continuous, stable, and effective drainage is one of the key factors to ensure the efficient development of CBM wells in the Baode block.

We propose a scheme to attain shorter multicast delay and higher efficiency in the data transfer of sensor grid. Our scheme, in one cluster, seeks the central node, calculates the space and the data weight vectors. Then we try to find a new vector composed by linear combination of the two old ones. We use the equal correlation coefficient between the new and old vectors to find the point of game and balance of the space and data factorsbuild a binary simple equation, seek linear parameters, and generate a least weight path tree. We handled the issue from a quantitative way instead of a qualitative way. Based on this idea, we considered the scheme from both the space and data factor, then we built the mathematic model, set up game and balance relationship and finally resolved the linear indexes, according to which we improved the transmission efficiency of sensor grid. Extended simulation results indicate that our scheme attains less average multicast delay and number of links used compared with other well-known existing schemes.