Factors affecting surface geochemical prospecting for oil and gas in Zoige Plateau and methods for the elimination of their effects

There are many factors of influencing surface geochemical prospecting for oil and gas,and the main influencing factors are different in different areas.Based on the characteristic analysis of the original surface geochemical prospecting data in Zoige Plateau,it is held that there is a great deal of difference in the geochemical prospecting data,and the difference is from the complex topography and geomorphology of the region and the difference in the lithology of the samples.For studying the influence of different topography and geomorphology on the surface geochemical prospecting indexes,the region is divided into 7 types of geologic-geochemical landscape systems by the surface remote sensing image of the region,and their background values are calculated respectively;for inhibiting the interference of lithology,by means of statistics,the original data of the samples which occupy a great percentage in the total samples and have a same lithology are found,taking them as a criterion,the total samples are classified,and then the original data are progressively corrected by the ratio method.Finally,three oil/gas prospecting zones in Zoige Plateau are presented by comprehensive abnormality analysis.