講演者：  Arkadiusz (Arek) Derkowski 先生
日時：12月16日（月）17:30~
場所：理学部1号館710号室
演題：Free and adsorbed methane in shales
要旨：
   Mudstones and shales have a complex nm-scale pore structure and a permeability of several orders of magnitude lower than conventional, coarser-grained reservoirs. If rich in organic (carbonaceous) matter (OM), in the course of diagenesis they can become self-sourced unconventional reservoirs of natural gas. Methane (CH4) present in shale formations occurs as two fractions: as free gas occupying pore structure and gas adsorbed on the rock compounds’ surface. The total methane in place content in a shale is limited by the overburden pressure and by the porosity of the rock.
   Due to their composition dominated by clay minerals, measuring total and effective porosity in shales remains a challenging step in hydrocarbons reserves calculation. Dual-Liquid Porosimetry (DLP) is a new method of measuring total porosity in shales and other ultra-low porosity geomaterials. DLP applies a combination of light kerosene (kerosene immersion porosimetry) and deionized water (water immersion porosimetry) as saturation-immersion fluids. The DLP method returns the maximum porosity fraction available for hydrocarbons and meets the best practice in petrophysics, overcoming the issues posed by conventional porosity measurement techniques.
   A significant amount of methane can be adsorbed physically on surfaces and in micro- and mesopores. In shales these textural features are commonly controlled by two compounds: organic matter (OM) and clay minerals. In OM-rich shales, the CH4 adsorption is predominantly controlled by OM micropore structure.  The mesopore surface area and volume do not play an important role in CH4 sorption.  The CH4 loading potential in micropores decreases with increasing thermal maturity of OM; the highest CH4 loading potential is linked to OM before metagenesis (Ro < 2%) where the adsorbed CH4 density equivalent was found greater than the density of liquid CH4.  This suggests that in addition to physical adsorption, absorption (dissolution) of CH4 in OM occurs. 
   In OM-poor rocks and sediments, clay minerals contribute to a large portion of the available surface area and microporosity in which methane is adsorbed. Opposite to OM-rich shales, where CH4 adsorption under high pressure corresponds to the sites occupied by CO2, methane adsorption capacity in clay minerals is controlled by N2-accesible micropore volume. CH4 adsorption sites are located mainly outside of the interlayer galleries of expandable clays unless they are open wide enough (e.g. pillared by organic cations or incompletely dried divalent cations). Clays adsorption capacity of CH4 is primarily controlled by the clay particles texture, as the crystallite planar dimensions and the way that they assemble.    

講演者：  對比地 孝亘 先生
日時：11月25日（月）17:30~
場所：理学部1号館710号室
演題：日本最南端の恐竜産地からー鹿児島県甑島列島での調査の最前線ー
要旨：鹿児島県甑島列島に分布する上部白亜系姫浦層群には蛇行河川を中心とする陸成堆積物が含まれており、断片的ではあるが陸生脊椎動物を多産する層準が存在する。ここ１０年間にわたる、熊本大学を中心とするチームによる調査の結果、陸生脊椎動物を産出する層準はカンパニアン中期とマストリヒチアンの主に２つあることがわかった。発表では、このような地質学的・古脊椎動物学的研究の結果について報告する。