Hydrocarbon Plays Evaluation of Eastern China
WU SHOU CHENG, Scientific Research Institute of Petroleum Exploration and Development of CNPC, Beijing, China
In eastern China there are 78 depressed basins, most of which are tilt-block basins. Each of them engenders petroleum generation except the Cretaceous sag basin of Song-Liao. These depressed basins set up in the order of older to younger depending on the change of the mantle convection. Consequently, the order of sedimentation and source-reservoir are changed and the exploration targets are also changed. Tan-Lu fault system is of great significance in NNW (early) and NEE (later) accompanying faults for exploration play. The Mesozoic depressions are coal-forming and the Tertiary depressions are mainly saliferous. There are 215 plays in eastern China. The hydrocarbon accumulation rules of these plays are: (1) As a result of the Tertiary tilt-block basins, compaction-flow basins contain imilar hydrodynamic, thermodynamic, and buried pressure fields. The direction of fluid flow is from generation center of the basin to the margins. So the hydrocarbon plays are distributed nearby the generation center and circum-center belt. (2) The richness of hydrocarbon plays is controlled by the form and distribution of source rock due to structural change of the tilt-block. The richest is the center uplift play and then the low-raised play, steep slope play, gentle-slope play, and, poorest, the low-lying play. (3) A variety of the composite hydrocarbon play models are formed by the different structure models (including the tilt-block model, fault model, and fold model), sedimentary model (including the sedimentary sequence model and facies patterns in horizontal model), and hydrocarb n model. Most of the recovery reserves are set in one or two plays even though there are many hydrocarbon plays in a tilt-block basin. (4) There are 3 types and 25 subtypes of petroleum pools formed by the different characters of plays. Therefore, there are numerous technologies, methodologies,and strategies of petroleum exploration.
AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)