关键词: 黄骅坳陷, 油气藏, 富集规律, 成藏模式

Abstract:

Chengbei step-fault zone in Huanghua Depression has diverse oil\|bearing target beds and hydrocarbon reservoirs, which are vertically stacked and laterally connected and have multiple hydrocarbon accumulations. The main control factors of the hydrocarbon reservoirs are abundant oil\|gas source, fine preservation conditions, fault terraces developed on bedrock buried hills, and longtime successive developing faults, among which, faults and cap rocks are the key factors controlling vertical hydrocarbon reservoirs. Fault terraces developed on bedrock buried hills and passage systems are the leading factors controlling lateral hydrocarbon reservoirs. The regularities of hydrocarbon accumulation are: in plan, hydrocarbons are distributed along the EW and NE major faults. In the vertical direction, hydrocarbons present in a ladder form from north to south, west to east. The thickness and physical properties of the reservoirs and the type of sand body control the extent of hydrocarbon enrichment. The location of traps and the shape of sand bodies control the thickness and oil domain of hydrocarbon reservoirs. Mudstone caprocks control the accumulation horizon of hydrocarbons, multiple transport systems determine that the unconformity surface is the favorable position for hydrocarbon accumulation. The associations of Chengbei fault terrace, unconformity surface and sandstone transport layer form various hydrocarbon migration and accumulation, and the accumulation model of terrace transport is the major model in the study area.

Key words: Huanghua Depression, Hydrocarbon reservoirs, Enrichment regularities, Accumulation model