Abstract
Abstract It is a common method to use sequence stratigraphic theory to identify favourable intervals in hydrocarbon exploration. The Lower Cambrian shale of Well Jiangye-1 in Yangtze Region in Xiuwu Basin was chosen as the research object. The content of excess silicon of siliceous minerals in shale was calculated quantitatively, and the concentration distribution of Al, Fe, Mn showed that the excess silicon is of hydrothermally origin and the shale deposited in an environment with hydrothermal activity. Using U/Th values in the study, combined with lithology and logging data, in order to divide sequences of the Lower Cambrian shale in Yangtze Region in Xiuwu Basin. The result shows that the shale of the Lower Cambrian shale is recognized as 1 2nd sequence (TST-RST, TST = Transgressive systems tract; RST = Regressive systems tract) and then further subdivided into 5 3rd sequences (SQ1-SQ5). During the deposition of SQ2 and SQ3, hydrothermal activity was active, and their excess silicon content was generally above 20%-30%. Rising sea level and active hydrothermal activity were beneficial for the enrichment of siliceous minerals and organic matter. Based on the comparison of the reservoir parameters, it tells that SQ2 and SQ3 have relatively higher content of TOC, higher content of brittle minerals (such as siliceous minerals, carbonate minerals and so on), larger effective porosity and higher content of gas, which make it as the most favourable intervals of the Lower Cambrian in Xiuwu Basin.
Highlights
It is a common method to use sequence stratigraphic theory to identify favourable intervals in hydrocarbon exploration
The content of excess silicon of siliceous minerals in shale was calculated quantitatively, and the concentration distribution of Al, Fe, Mn showed that the excess silicon is of hydrothermally origin and the shale deposited in an environment with hydrothermal activity
In order to analyse the sedimentary environment of Early Cambrian, the concept and the application of excess silicon have been introduced in the study
Summary
It is a common method to use sequence stratigraphic theory to identify favourable intervals in hydrocarbon exploration. Using U/Th values in the study, combined with lithology and logging data, in order to divide sequences of the Lower Cambrian shale in Yangtze Region in Xiuwu Basin. The emergence and development of unconventional hydrocarbon exploration, an advanced understanding of deep water shale depositional systems has occurred This has resulted in increased production from shale gas resources in North America [1,2,3]. Wedepohl (1971), Adachi et al (1986) and Yamamoto (1987) tried to differentiate between hydrothermal silicon and biogenic silicon by Al-Fe-Mn ternary diagram [24,25,26] These two calculation methods are combined to confirm the existence and the content of excess silicon of shale by quantitative calculation. The study area is located in the west of the Xiushui-Wuning syncline, a new exploration area covering approximately 600 km (Figure 1)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
