The Research In Labotorial Methodologies And Analytical Assessment To Shale Gas Content

As highlight and frontier in the respect of resource, the exploration and exploitation for shale gas has aroused wide focus and attention domestically and abroad. The very success of shale gas in North America also stimulates this trend in gas exploration. Compared with U.S. and some other developed countries, the exploration for shale gas in china is still in the stage of fast initiation. It is still quite vulnerable in the aspects of laboratorial techniques in shale content, and the relative evaluation. Gas content is the key parameter and important basis in the resource assessment, favorable zone optimization, deployment and determination in shale gas exploration and exploitation. Due to these factors, there is the urgency in theoretical analysis and laboratorial research about shale gas content.Through the analysis to the attributes and composition of gas content of shale, the different methodologies of gas content acquiring has been researched. On the basis of case statistics and relative analysis, the dominative factors of shale gas content are revealed. The feasible technique for shale gas content assessment is provided. Eventually, considering the success of North America in shale gas exploration and the actual conditions of shale gas preservation in china, the reference scales in the effectiveness of shale gas content is also offered in this dissertation.The features about shale includes remarkable capability of gas containing, variable phase states in the three forms of gas gathering, which are free gas, adsorbed gas and solution gas. Due to the difference in the shale type and gas gathering condition, the difference in composition of shale gas exists. This dissertation intergrates the research about areal geological attributes of shale gas in china. The characteraitics of gas content for different types of shale are revealed. The shale types includes highly evolved marinre facies shale in South China, Mesozoic and Cainozoic continental facies shale in North China and upper Paleozoic shale in coal measure strata which is widely developed with the transitional feature between marine and continental deposition.The measurements for gas content can be concluded as 2 types of method, which are in direct method and indirect method. Direct method includes in-situ desorption and sealed coring. Indirect method includes isotherm adsorption test, logging data analysis, statistical method. There area different characteristics of there methods, the focal points of the methods are also different in testing gas content. In-situ desorption and sealed coring are the most direct and reliable technique. But the cost of sealed coring is quite high. In isotherm adsorption, the capability of methane adsorption in shale can be calculated, which is the max adsorption gas content. Logging data analysis is developed from the experiments and logging technologies. As a computing method, there is a very wide application in shale gas industry. Due to there mentioned factors, the applying these methods to acquiring shale gas content, there must be full a thorough consideration about the feasibility and applicabilityBased on theoretical and method analysis, different influential factors about shale gas content such as geochemical and geophysical scales, mineral composition, formation depth, temperature and pressure, etc. are researched through plentiful experimental data statistics. The positive relationship is obtained between gas content and TOC content. Besides, the shale maturity, reservoir properties and preservation conditions are also very influential to shale gas content.From the research, the methods such as laboratorial prediction method and probabilistic method etc. are provided. There is the case study and analysis about the feasibility and applicability of these methods, taking Southeast Chongqing as instance. On the basis of gathering and comparing the attributes of shale gas in North America, the effective economic constraints about the viaration of Chinese shale gas content in different formation depths are established under consideration and integration of the geological uniqueness of China. Through this research, some beneficial points can be made to the development of shale gas research in China.