症例は55歳の女性．食後の嘔吐を繰り返すと，当院を受診し入院した．腹部CTで十二指腸水平脚に浸潤・閉塞，上腸間膜静脈を閉塞し，大動脈に接した局所進行切除不能膵癌と診断した．開腹下に胃空腸吻合および腫瘍の生検を行い，膵癌の病理診断を確定した．UGT1A1（uridine diphosphate glucuronosyltransferase 1A1）遺伝子多型＊28，＊6複合ヘテロ接合体を持つも，比較的若く全身状態も良いため，FOLFIRINOX療法（オキサリプラチン，イリノテカン，フルオロウラシル，レボホリナートによる併用療法）をイリノテカンの減量および注意深い副作用への対処の下，また途中から好中球減少にペグフィルグラスチム予防的投与を行いながら，治療開始から2年6カ月継続した．腫瘍の著明な縮小は無いものの，比較的長期に病勢を制御し生存を得ているので，報告した．

The Onnagawa shale is a middle Miocene deposit that extends along the Akita coastal area. This formation contains organic carbon enriched siliceous mudstones deposited in the basins during the early stages of the Japanese sea opening. Some researchers in petroleum geochemistry have demonstrated that these organically enriched rocks possess attributes common to oil source rocks. JOGMEC has previously perfomed shale oil reservoir characterization of the Onnagawa shale, pilot hydraulic fracturing tests, and coring through the Onngawa shales sequence. The main goal of this paper is to use methods to estimate rock properties characterized by porosity and permeability to develop an understanding of fraccability based on lithofacies and mineral composition and their distribution in the Onnagawa Formation.

Core sample from the Onnagawa shale were drilled at the Unosaki coast in the Oga peninsula. Rock property, mineral composition, and lithofacies were analyzed by CMS-300, QEMSCAN, and FIB-SEM in JOGMEC-TRC. The study results identify successes or fail parts of hydraulic fracturing depending on lithofacies and mineral compositions and indicate that 1）the lihofacies of the Onnagawa shale are dark gray to light gray colored massive, bedded, and laminated. 2）the porosity and permeability values in the light gray colored facies are relatively higher than dark gray colored facies. 3）the QEMSCAN shows the Onnagawa Formation is characterized by layered carbonate concretions with dolomite and calcite and consists chiefly of quartz with clay minerals and framboidal pyrite. 4）hydraulic fracturing tests succeeded in dolomite and calcite composed carbonate concretion layers.