Abstract: The hydrocarbon heterogeneous distribution is the universal law in oil and gas bearing basin，especially in complex
fault-block oilfield. The crude oil properties and the enrichment of oil and gas accumulation of different fault-blocks or different
layers vary greatly in the same complex fault-block zone. Due to the difference of heterogeneity and diagenesis of reservoir
in the same fault-block，hydrocarbon is also distributed heterogeneously. The types of oil reservoirs in complex fault-block
oilfields are complex and changeable，and often related with fault. The diversity of configuration of fault and sand body and the
properties of the fault are the key factors leading to hydrocarbon heterogeneous distribution. The scale of fault，fault occurrence，
mechanical properties and the combination style of the fault in the plane or in profile etc，also have an important influence on
oil and gas enrichment. Therefore，the concept of“blocks control petroleum enriched areas”will favorably contribute to oil
and gas exploration.

Key words: complex fault-block oilfield, heterogeneous hydrocarbon distribution, main controlling factor, configurationpattern of fault and sand body, fault property