Time: 11:30 am Virtual Social Icebreaker, Noon Speaker Presentation

Speakers: Dr. Michael Grammer and Post Doc Researcher Yulun Wang, Oklahoma State University

Title: Facies Architecture and Reservoir Characteristics of the Caney Shale, Ardmore Basin, Southern Oklahoma, USA

Abstract: The late Mississippian Caney Shale in the Ardmore Basin (southern Oklahoma, USA) has organic-rich intervals and is in the oil window, but its production is sparse and unpredictable. To assess the production potential of the Caney Shale, we are characterizing depositional facies, reservoir properties, and pore system architecture within a sequence stratigraphic frameworkdefined from core. Preliminary results reveal a variety of mudstone, siltstone, and carbonate facies associated with various depositional processes on a slope or ramp system. These processes include low energy background sedimentation of siliciclastic-rich facies and intermittent high energy event deposition (turbidity current, debris flow, longshore current, storm) of carbonate-rich facies sourced from a shallower water platform. Vertically, these facies show upward decreasing and increasing trends of carbonate-rich facies relative to siliciclastic-rich facies at multiple scales, reflecting a hierarchy of facies stacking patterns associated with cyclic variations in sea-level and sediment supply. When tied with gamma-ray (GR) logs, fining- and coarsening-upward packages can be defined correspondingly, suggesting that a hierarchical sequence stratigraphic framework can be defined using core and GR logs. When correlated to porosity logs, these trends commonly show upward increasing and decreasing trends, indicating the direct impact of facies variations in reservoir distribution. At micron to nanometer scale, calcareous siltstone contains abundant intraparticle pores associated with organic matter and clay, whereas carbonate facies contain relatively larger interparticle/intercrystalline pores. This core-to-log tie indicates that an integrated sequence stratigraphic framework can enhance reservoir characterization and prediction at multiple scales. In particular, carbonate-rich facies show distinctively lower value GR and porosity log responses, indicating their sealing potential, whereas adjacent mudstone and siltstone are better reservoirs. Being analogous to the Wolfcamp Formation (Permian Basin), these facies are potentially part of the axis (carbonate) and fringe (mudstone, siltstone) of a vertically stacked submarine fan system. Therefore, connecting facies architecture with reservoir properties in a hierarchical sequence stratigraphic framework allows for enhanced reservoir characterization at multiple scales and improved exploration and production strategies.

Bio: Yulun Wang is a post-doctoral researcher in the Boone Pickens School of Geology of the Oklahoma State University, and is currently focusing on the integrated reservoir characterization of the Caney Shale play in southern Oklahoma. Yulun was born in Panjin, which is a city powered by a major oil field in northeastern China. Driven by his curiosity about the pumpjacks in his backyard, Yulun studied Petroleum Geology in Jilin University (China) which earned him a Bachelor’s degree. He later moved to the University of Tulsa and worked with Dr. Robert W. Scott on the Lower Cretaceous shallow-marine carbonate strata in southwest Texas, which earned him a M.S. degree in Geology. Learned about the boom of unconventional resource plays at that time, Yulun became interested in characterizing these reservoirs and moved to the Boone Pickens School of Geology, Oklahoma State University, to pursue a Ph.D. degree. For his dissertation research which was mentored by Dr. G. Michael Grammer, Yulun focused on the sequence stratigraphic framework, natural fracture system, and rock mechanical properties of the unconventional “Mississippian Limestone”/STACK play in north-central Oklahoma, USA. Benefited from collaborations with industrial sponsors and the University of Miami (CSL – Center for Carbonate Research), Yulun also worked on the Wolfcamp Formation in the Permian Basin and the Vaca Muerta Formation in Argentina. Yulun was the recipient of the AAPG Grants-in-aid Award (2016, 2017) and the Oklahoma Geological Foundation Davis Geology Fellowship (2015), and was a Geology Intern at Tiptop Oil and Gas (Sinopec) (Oklahoma City, 2016).