Title: “Relating Gas Accumulation, Hydraulic Fracturing and Production to Complex Geology: The Lower Paleozoic Marine Shales on the Yangtze Platform in South China”

Date: December 9, 2015
Time: 3:00-4:00 p.m.
Place: WEB L102

There will be light refreshments afterwards.

Please plan on attending this seminar. It could really impact your industrial and research attitudes. Dr. Shu Jiang is a Research Assistant Professor and the Energy & Geoscience Institute’s China Coordinator.

Industrial activities and our ongoing research on Lower Paleozoic marine shales on the Yangtze Platform in South China indicate that the distribution of prospective shale plays, the challenge of shale gas exploration, as well as the effectiveness of hydraulic fracturing and production are all related to a very complex geologic setting. The key geologic variables include the regional tectonic and depositional settings, the geologic history, and the rock properties. Relevant rock properties include heterogeneous lithofacies, variable geochemistry and mineralogy as well as the presence of natural fractures and the reservoir pressures.

Detailed geologic studies indicate that the emerging Cambrian and Silurian shale plays on the Yangtze Platform were deposited in the intra-shelf low to slope environments away from clastic dilution. High quality shale reservoirs – with high organic content, favorable porosity and hydrocarbon content and abundant brittle minerals – are usually located in transgressive system tracts to early highstand systems tract intervals deposited in anoxic settings. Distinct shale gas production rates in different regions with similar shale properties (sedimentology, geochemistry, mineralogy and petrophysics) are probably related to different tectonic settings.

The Yangtze platform can be divided into three geologically-different regions

  1. a tectonically stable area with broad syncline and gentle fold in the Sichuan Basin in the Upper Yangtze Platform,
  2. a tectonically transitional area with tight synclines and many faults in the Upper Yangtze Platform outside the Sichuan Basin and in the Middle Yangtze Platform, and,
  3. a tectonically active area with high structural deformation due to at least four intense tectonic events on the Lower Yangtze Platform.

High shale gas content and high production rates from the overpressured marine shale reservoir in the recently discovered Fuling Shale Gas Field in the SE Sichuan Basin reveal good shale gas accumulations and production potential in the tectonically stable area. Exploration and production tests in the tectonically transitional area show dramatically reduced production rates in slightly under-pressured synclines and little or no production in areas close to faults. The tectonically active area has almost no shale gas shows.

The variations of shale gas content, overpressure and production in different tectonic settings indicate that post-depositional tectonic activities strongly influence gas generation, accumulation, leakage, pressure history and production. Multi-stage, intensive tectonic movements could have disrupted shale gas accumulation and caused the loss of early accumulated shale gas. Tectonics also affects the complexity of induced fractures created by hydraulic fracturing. Stress field analysis and hydraulic fracturing simulation imply that organic-rich siliceous marine shale intervals in the areas less influenced by the collision of the Indian and Eurasian plates are more favorable for hydraulic fracturing. The sweet spots with good reservoir quality and completion quality are likely located in broad synclines and anticlines in tectonically stable areas with small far-field horizontal stresses.

Shu Jiang received a B.S. in Petroleum Engineering and a Ph.D. in petroleum geology, both from China University of Geosciences at Wuhan. He worked for CNOOC (China National Offshore Oil Corporation) and the University of Colorado at Boulder before he came to the Energy & Geoscience Institute (EGI) at the University of Utah in 2010. He is a Research Assistant Professor and is EGI’s Coordinator for the China Program. He is also an Adjunct Professor at the China University of Geosciences in Wuhan and at the China University of Petroleum (East China) at Qingdao.

Dr. Jiang has more than 15 years’ experience in geology and engineering for conventional and unconventional oil and gas. His worldwide industry and academic experiences span continental to deep water basin setting (eastern China lacustrine rifted basins, northern China cratonic basin, western China foreland basins, the South China Sea passive margin, basins in the Rocky Mountains, to deep-water Gulf of Mexico, Angola, and Northwest Shelf Australian basins). In the last several years, more than 20 multinational oil companies and government organizations have supported his research on shale geology and engineering.

He is a certified petroleum geologist (CPG), an active member of AAPG, and SEG. He served as AAPG sub-committee chair for the 2013 IPTC and session chair for the 2013 AAPG Annual Meeting, among numerous other roles at conferences and meetings. He also serves as an advisory member of the AAPG Shale Gas and Liquids Committee. He has published 61 peer-reviewed papers in leading journals and books, e.g., AAPG Bulletin, Energy & Fuels, Marine and Petroleum Geology, Journal of Asian Earth Sciences, etc.