Physical simulation and discussion of the formation mode of the Silurian oil reservoirs in the Shuntuoguole region, Tarim Basin

Physical simulations were carried out with the S9 reservoir in the Shuntuoguole area of the Tarim Basin to study the hydrocarbon accumulation pattern in the lower section of Silurian Kalpintag Formation. Hydrocarbon mainly originated from the Cambrian-Ordovician source rocks. Faults provided pathways for hydrocarbon migration, and were most active during the late Silurian and Permian, which matched with two accumulation stages. A physical model was made according to the geologic structure of target section in S9 reservoir. Hydrocarbon was injected from the bottom of the model by continuous and steady or intermittent way, and then migrated upwards through faults. We mainly used the intermittent injection, and carried out simulations at pressure differences of 5,10,15 MPa. The faults with high, low and flexible permeability were applied in the simulation. The controls of fault property, pressure difference and injection way on hydrocarbon migration and accumulation were discussed, so as to study the necessary geologic conditions during hydrocarbon accumulation stages. The results showed that the lower section of the Silurian Kalpintag Formation was enriched with hydrocarbon during the Silurian-Devonian and Permian-Triassic, indicating for a possibility of early and large-scale reservoir.