Application of multi-parametric geochemical exploration to hydrocarbon potential evaluation for trapped structure in desert area: A case study of TD-2 structure in Tarim basin, China

TD-2 structure locates in the eastern area of the central uplift zone of Tarim basin, China. Although it is a basement-uplift anticline type structure which is verified by seismic and gravity exploration, according to analysis of regional geological evolution history, and it should have potential good for oil and gas, the further exploration such as drilling is suspended because of lacking geochemical information. Therefore, multi-parametric geochemical survey is conducted. These geochemical parameters include free hydrocarbons (C1-C5), acid hydrocarbons (C1-C5) of soil, ΔC amd Hg. Interpretation of the results leads to the conclusions that the free hydrocarbons are obviously more viable than other geochemical parameters for oil and gas potential evaluation of TD-2 structure in desert area, and the shapes of near-surface geochemical anomalies and geochemical characteristics parameters suggest that TD-2 structure is a dry gas-bearing structure at the early-middle dissipation stage. So TD-2 structure should have promising potential for oil and gas, and the results of multi-parametric geochemical survey have provided important information for further exploration.