Sedimentary facies distribution and the characteristics of transitional shale in the upper Palaeozoic in northeast Ordos
- PDF / 3,234,262 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 60 Downloads / 173 Views
ORIGINAL PAPER
Sedimentary facies distribution and the characteristics of transitional shale in the upper Palaeozoic in northeast Ordos basin, China Chunqi Xue 1 & Jianhua Zhong 1 & Mengxiang Hou 1 & Fengtian Li 1 & Chaofeng Peng 1 Received: 17 October 2018 / Accepted: 18 July 2019 # Saudi Society for Geosciences 2019
Abstract The Taiyuan formation that was formed in the late Permian period of the upper Palaeozoic in the Linxing area, north-eastern of Ordos basin, China, shows the marine and continental interdepositional systems, as well as the resource potential of shale gas. Through a field outcrop, core observation, and well logging data, the Taiyuan formation can be divided into Tai1 (p1t1) and Tai2 formations (p1t2). The main depositional environments of the region in Taiyuan formation included tidal flats, swamp, and lagoon which is also a good depositional environment for high-quality shale development. During the Taiyuan formation period, the sedimentary sea level in the study area rose and fell frequently, and the barrier coastal sedimentary system is mainly developed. In addition, the shale has superior development characteristics: The Taiyuan formation shale has a considerable amount of material, with an accumulated thickness of greater than 30 m; the average organic carbon content in the Taiyuan group is 3.34%, and the content in the Tai2 formation (p1t2) is slightly higher than in the Tai1 formation (p1t1); a high thermal evolution content is developed with an average vitrinite reflectance (Ro) of 1.33%; the Kerogen type is the III model, in which gases are mainly developed; the brittle mineral content in the rock mineral components is high, and the brittleness index is generally greater than 50%, which indicates a high rate of compressibility. Therefore, the Taiyuan formation indicates a marine and continental interdeposition and has a high exploration and development potential for shale gas. Keywords Marine and continental interdeposition . Sedimentary environment . Taiyuan formation . Shale gas
Introduction With the successful development of shale gas in the USA in 2000, global unconventional oil and gas research, and especially shale gas research, was carried out enthusiastically. High oil and gas production rates in the Barrent, Antrim, and Arkoma basins in the USA show that geochemical and reservoir physical parameters are often used as reference indicators for favourable shale gas resource evaluation zones (Jiang et al. 2008). Statistically, shale gas production in the USA reached 2847 billion cubic metres in 2011, accounting for approximately 40% of the natural gas production in the USA (Wang et al. 2017), and it became one of the main resource supply. Shale gas, as a kind of unconventional oil and Editorial handling: John S. Armstrong-Altrin * Chunqi Xue [email protected] 1
China University of Petroleum (East China), Qingdao 266580, China
gas resource, is often formed in dark mudstone rich in organic matter. It has a low porosity and low permeability reservoir physical characteristics, and
Data Loading...
