Abstract:

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.

Key words: carbonate rock, complex accumulation, hydrocarbon accumulation pattern, Tazhong Palaeouplift, Tarim Basin