Hydrocarbon accumulation model for Neogene traps in the Chengdao area,Bohai Bay Basin,China |
| |
| Institution: | 1. Key Laboratory for Geo-hazards in Loess Area, MLR, Xi''an, 710054, China;2. Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, 266100 Qingdao, China;3. Key Laboratory of Marine Environmental & Ecology, Ministry of Education, 266100 Qingdao, China;4. Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, 266061 Qingdao, China |
| |
| Abstract: | Chengdao is an offshore area in the Bohai Bay Basin that contains approximately 25.7 × 108 bbl of oil and gas reserves within the sandstone reservoirs in Neogene strata. However, previous predictions of hydrocarbon accumulation in Neogene traps are inaccurate, resulting in a current failure rate of 50% when drilling for hydrocarbons in this area. To build an improved exploration model for Neogene traps, we select 92 traps from Neogene strata in the Chengdao area to quantify the filling degree, which is an indicator of hydrocarbon accumulation efficiency. The quantified filling degree is based on actual geological and exploration data and differs significantly among various trap types. The filling degree of traps also varies significantly with their structural locations and decreases generally from the northwest to the southeast along the Chengbei Fault zone. Vertically, the filling degree is highly heterogeneous, initially increasing from the bottom to the middle of Neogene strata and then decreasing towards the top of the strata. These Neogene hydrocarbon reservoirs are sourced from the Paleogene, and as they lay vertically away from the source rocks, their hydrocarbon enrichment is constrained largely by hydrocarbon migration distance and vertical migration pathways. The sealing capacity of faults and cap rocks, sandbody orientation and reservoir sedimentary facies determine the maximum column height, which in turn affects the amount of hydrocarbon accumulation within these traps. A scatter plot analysis of individual controls and volumetric filling for each trap type is compiled using multivariate linear regression analysis to quantify controls and the dominant control of hydrocarbon accumulation is determined. |
| |
| Keywords: | Bohai Bay Basin Filling degree Neogene sandstone reservoirs Constraining factors Hydrocarbon accumulation |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
