Abstract:Many shallow gas or heavy oil reservoirs have been found over 50 years of exploration and development in Jiyang depression.Research on the distribution pattern and origin of shallow gas and heavy oil is very important to guide future exploration of oil and gas.Two conclusions were drawn by analyzing the spatial distribution and geochemical characteristics: ①The distribution of shallow gas and heavy oil reservoirs are paragenetic. Shallow gas reservoirs often develop above or in the updip direction of heavy oil reservoirs.Meanwhile, heavy oil reservoirs exist under or in the downdip direction of many shallow gas reservoirs;②Shallow gas and heavy oil reservoirs have symbiotic genesis. Shallow gas reservoirs consist mostly of biodegraded and released dissolved-gas which mainly come from underlying or downdip reservoirs. Consequently, oil in these reservoirs becomes heavy oil due to biodegradation and natural gas dispersion. This paper proposes some ways to explore shallow gas and heavy oil reservoirs jointly: search for heavy oil reservoirs according to the distribution of known shallow gas reservoirs and vice versa; or use seismic bright spot to locate gas reservoirs, and discover related heavy oil reservoirs via these gas reservoirs.