乌尔逊-贝尔凹陷有利区预测与勘探目标优选

乌尔逊-贝尔凹陷是海拉尔盆地最重要的油气发现区，现已发现5个大的油气聚集带，勘探前景好。油气成藏主控因素研究表明：研究区具有明显的源控、储控和断控成藏特征，油气藏主要分布在距有效烃源岩中心10 km范围内，NEE和NNE走向断层1 km范围内油气富集程度高，粉砂岩和砂砾岩为最有利的储集岩性，扇三角洲前缘亚相为最有利的沉积相。应用控藏要素多元叠合法对该凹陷南屯组二段进行了成藏有利区综合评价，优选出三级有利成藏区，通过分析有利区内断层型圈闭的断层封闭性能，对凹陷南屯组二段圈闭进行了成藏评价，优选出10个有利勘探目标，为凹陷下步勘探指明了方向。

Forecasting of Favorable Hydrocarbon Exploration Area and Evaluation of Exploration Targets in Wuerxun-beier Depression

Wuerxun-Beier Sag is the major hydrocarbon discovery area in Hailaer Basin, five major hydrocarbon accumulation belts have been found which reveals great exploration potential of the area. Research on hydrocarbon accumulation control factors shows that the distribution of effective source rocks, faults and favorable reservoir determine the location of hydrocarbon accumulation, hydrocarbon reservoirs mainly distribute within 10km from the effective source rocks center and within 1 km from the faults with a direction of NEE and NNE; siltstone and sandy conglomerate are the most favorable reservoir rocks, fan delta front is the favorable sedimentary facies. Considering that almost all the traps are related with faults, four kinds of fault-related traps are classified. Based on the study on main control factors, which are mentioned above, a multiple-factor superposition forecasting method is put forward, that is, the area containing all the favorable hydrocarbon accumulation conditions is the most favorable exploration area, and by using this method, the favorable hydrocarbon accumulation area of K₁n₂ formation is figured out, and 10 favorable targets of K₁n₂ formation are selected for next exploration by analyzing the sealing ability of the faults which control the boundary of the fault-related traps.