He Yuan has received his BS degree in Yangtze University, China and MS degree in Petroleum Engineering from Research Institute of Petroleum Exploration & Development, China. Presently, he is engaged with shale gas geology research in China and focuses on geological characteristics, sedimentary model and reservoir characterization. He has published over 6 papers in the oil and gas development fields.
Abstract
There are two sets of organic-matter marine shale containing upper Ordovician Wufeng Formation and the lower Silurian Longmaxi Formation in southern China. These resources provide the basis of building several commercial zones of shale gas development. Zhaotong area is in the southern margin of the Sichuan basin, Jianwu syncline south wing. In the area of high quality shale section, thickness of Wufeng and Longmaxi 11 formation ranges from 35 to 40m. By use of well drilling date and core samples, these samples were analyzed throughout incorporating a variety of test methods. The results show that: (1) the content of clay is highest in the mineral composition in the Zhaotong area, average 34.21%, (2) brittleness minerals is quartz the most content, feldspar ranking the 2nd and then calcite, dolomite and a small amount of pyrite, (3) Type II1 dominates in all organic materials, while Type II2 dominates in the upper formation, (4) The maturity of organic matter is on the range of 2~3.5%, reaching a mature stage of generating dry gas, (5) TOC content is about 2.9~14.0% by using actual measurement, average of 7.0%, (6) Logging results show that the porosity of high quality shale is 2.05~5.45%, average of 4.50% and (7) Brittleness index of shale is 54.5~61.1% by calculating the brittleness index, average of 57.4%. The comprehensive results indicate that Wufeng and Longmaxi 11 formations possess the highest brittle mineral content and a larger brittle index, has an enormous potential of hydrocarbon generation and has a larger formation porosity, which demonstrates the practice of establishing a commercial shale plays.