Abstract:

The exploration in Erlian Basin in recent years shows that the lithologic reservoir has more predominant conditions in formation and distribution.The predominance in formation includes 4 aspects: ① lithologic traps have more forming periods and times, and it is helpful to entrap oil; ② lithologic reservoirs can be formed with only primary migration and short distance secondary migration; ③ lithologic reservoirs can be charged with oil earlier than structure reservoirs; ④ lithologic reservoirs have more advantaged sealing conditions.Lithologic reservoirs experience little destruction in the later structural activities: uplift and fault activities can destroy lithologic reservoirs little than structure reservoirs. The scope of distribution of lithologic reservoirs is more abroad: ① lithologic reservoirs can distribute not only in steep slope structure belt, but also in gentle slope structure belt and sag belt; ② lithologic reservoirs can enrich not only in low system tracts(LST), but also in high system tracts(HST); ③ lithologic reservoirs can distribute in all types of geopressures. So it is concluded  that the lithologic reservoirs in Erlian Basin have predominant conditions in their formation and distribution.

Key words: Erlian Basin, lithologic reservoir, formation and distribution, predominant characteristics