Based on the analysis of the typical oil and gas pools in the Lower Paleozoic carbonate rocks of the Tazhong Palaeouplift and by using geochemical analytical methods

that the Cambrian was the major source rock contributing to the marine carbonate reservoirs in Tazhong area and the natural gas in the Lower Paleozoic reservoirs was mainly cracked gases from fossil oil reservoirs were clarified.The marine carbonate reservoirs in the Tazhong palaeouplift was characterized by complex hydrocarbon accumulation features as generated in lower zones and preserved in upper zones

multiple reservoir-cap rock assemblages and multi-stage hydrocarbon accumulation.The complex hydrocarbon accumulation pattern was also established for the marine carbonate reservoirs in the Tazhong Palaeouplift

and three potential exploration targets

namely reef-bank complex

karst unconformity and inner dolomite

were nailed down in the Lower Paleozoic of the Tazhong palaeouplift.