Sedimentary and reservoir architectures of MB1-2 sub-member of Middle Cretaceous Mishrif Formation of Halfaya Oilfield in Iraq

SUN Wenju,QIAO Zhanfeng,SHAO Guanming,SUN Xiaowei,GAO Jixian,CAO Peng,ZHANG Jie,CHEN Wangang

Fig. 4. Bioclastic shoal microfacies in MB1-2 sub-member of Mishrif Formation in Well N195 of Halfaya Oilfield. (a) 3061.00- 3061.50 m, grainstone with cross-bedding and visible grading sequence change, core photo; (b) 3060.00-3060.50 m, packstone with obvious grain sense, core photo; (c) 3061.11 m, grainstone with intergranular pores, bioclasts of mainly non-fixed bivalves, echinoderms and spherulites, cast thin section; (d) 3060.12 m, grain dominated packstone, with intergranular pores and mold pores, and marl filling between grains, cast thin section.