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在低温显微测温分析过程中,笼形水合物可能会形成于含水的、富气体的流体包裹体中。气体在笼形水合物和残留流体之间的不均匀分配,是温度、压力和总成分的函数。尤其是在含多成分气体的包裹体中,各种气体在笼形水合物中的选择性分配会强烈影响显微测温资料的解释。气体在残留流体中亏损(被笼形水合物吸收)的绝对程度,依赖于气体成分以及水和富气体流体的相对比例。笼形水合物体系中的平衡相关系可以模式化,以便作笼形水合物存在的校正。CO_2-CH_4-H_2O的定量模拟以及CO_2-N_2-H_2O、N_2-CH_4-H_2O和H_2S-CH_4-H_2O的研究,指示了气体不均匀分配的方向和程度以及笼形物的温度-压力-成分的稳定性。例如,在地质上合理的压力范围内,H_2S和CH_4在笼形水合物中的分配远比N_2强而在CO_2和CH_4之间,及在CO_2和N_2之间的分配方向则是温度、压力和成分的相对含量的函数。 单气体系和双气体体系之间的实验数据的对比以及John等(1985)的模式表明,该模式能正确地预测笼形化合物稳定性,因而对流体包裹体的研究很有用。
During cryogenic microscopy, clathrates may form in aqueous, gas-rich fluid inclusions. The uneven distribution of gas between the clathrate hydrate and the residual fluid is a function of temperature, pressure, and total composition. Especially in multi-component gas inclusions, the selective distribution of various gases in the clathrate hydrate will strongly affect the interpretation of microscopic temperature data. The absolute degree of gas loss (retained by the clathrate hydrate) in the residual fluid depends on the gas composition and the relative proportions of water and gas-rich fluid. The equilibrium phase relationship in the clathrate hydrate system can be modeled for the correction of the presence of clathrate hydrate. The quantitative simulation of CO_2-CH_4-H_2O and the study of CO_2-N_2-H_2O, N_2-CH_4-H_2O and H_2S-CH_4-H_2O indicate the direction and degree of nonuniform gas distribution and the temperature-pressure- stability. For example, the distribution of H 2 S and CH 4 in clathrates over geologically reasonable pressures is stronger than that of N 2 and the distribution between CO 2 and CH 4, and between CO 2 and N 2, is temperature, pressure and A function of the relative content of ingredients. Comparisons of experimental data between single- and double-gas systems and the model of John et al. (1985) show that this model can correctly predict the stability of clathrates and therefore is useful in the study of fluid inclusions.