Abstract: Hydrocarbon generation from source rocks follows specific temporal and spatial sequences while tectonic activities and trap formation have different stages. In addition, large volumes of pyrolysis gases resulting from enriched paleo-reservoirs and scattered residual crude oil will migrate and accumulate. Therefore, reservoir formation may undergo multiple stages. The principle of segmented capture of oil and gas was employed to analyze the Sinian-Cambrian natural gas reservoir formation processes and patterns of the three typical reservoir architecture types. The studied reservoirs are the Weiyuan, Ziyang, and Gaoshiti-Moxi in the southern part of the Sichuan Basin. The reservoir formation probabilities of other unknown areas can thereby be estimated. It is concluded that, the Sinian-Cambrian traps in the Gaoshiti-Moxi Area, being a succeeding paleouplift, captured oil and gas formed during nearly all stages. This occurred from the early hydrocarbon generation from source rocks to the late-stage gas generation from kerogen. Meanwhile, the Weiyuan and Ziyang areas only captured oil and gas resulting from some stages. For an unknown area, namely the Luzhou Uplift, it is possible to capture the natural gas resulting from the peak generation stage and the subsequent stages. These include the pyrolysis gases from scattered residual crude oil and late-stage kerogen. If the configurations of the reservoirs and traps are well determined, the area has a great potential for natural gas exploitation.

Key words: principle of segmented capture of oil and gas, natural gas reservoir, Sichuan Basin, Sinian-Cambrian