Abstract: Reservoirs in Badaowan Formation in Xia79 Well zone in northwestern margin of Junggar Basin feature in strong heterogeneity and poor permeability, which result in vague understanding of target reservoirs distribution and have a negative effect on integrated development of oil regions. Exploration using surface-borehole electric method is conducted, which shows that oil and gas distribution is controlled by both structural and lithologic factors. The region where oil bearing sand bodies well developed is high-value anomalous region (favorable for hydrocarbon accumulation) of such comprehensive parameters as apparent resistivity and double-frequency phase. The region where mudstone well developed is low-value anomalous region (unfavorable for hydrocarbon accumulation). Saddle shaped anomalous region where low-value anomalous region transits to high-value one is a connection part that oil and gas migrates from low sand bodies to high ones, which is relatively favorable for hydrocarbon accumulation. Based on comparing the drilling results of 15 wells, the results of 13 wells accord with oil and gas prediction while two do not. Prediction accuracy reaches 86.7%.

Key words: surface-borehole electric method, apparent resistivity, double-frequency phase, comprehensive parameter, Xia79 Well, Junggar Basin