Print this pagePetroleum Generation and Migration Modelling In Daqing Oil Field, Songliao Basin, China
YU, Z., X. PANG, and A. S. PEPPER
Songliao Basin, located in the northeastern China, is a non-marine, continental petroliferous basin which contains the Daqing giant deposit with billion barrels. The basin fill comprises mainly Jurassic and Cretaceous clastic sediments; overlying Cenozoic deposits are thin and mostly unconsolidated. There are multiple lacustrine source rocks in the Songliao Basin. The middle Cretaceous Qingshankou I, presently buried at 1100 m and deeper, is mature and responsible for generation and expulsion of the produced oil. The shallower Nenjiang I (younger middle Cretaceous) organic rich rocks remain largely immature. Another more speculative kitchen contains deeply buried Jurassic black shales deposited during the early rifting stage.
We reconstructed the basin's burial and thermal history based on geologic data and thermal stress indicators, using a 1-D basin model (GENEX_BP). Then we studied the petroleum generation, expulsion and migration history using a 2-D model (TEMISPACK), applying global kinetic parameters for lacustrine source rocks and a novel relative permeability model for migration through fine grained rocks. The results of the study suggest that: (1) the uplift and erosion at the Cretaceous-Tertiary boundary is about 1.0-1.5 km with a mildly elevated paleo heat flow (1.5-2.2 HFU), rather than a mild erosion and high paleo heat flow; (2) basement topography influences thermal patterns; (3) the oil accumulations are dominantly charged by the Qing I source rock; (4) high oil relative permeability in fine-grained rocks and close source-carrier juxtaposition promotes efficient migration; (5) Jurassic-sourced gas accumulations are possible in the deep central and shallow western part of basin.