印尼巴里拖盆地东部坳陷油气差异分布控制因素分析

The Control Factor of Hydrocarbon Different Distribution in the Eastern Depression of Barito Basin in Indonesia

巴里托盆地是印尼重要的含油气盆地,油气分布存在显著差异,已发现油气藏集中分布在坳陷北部小范围区域,其他地区无油气发现。研究认为,生烃中心和成藏模式是盆地油气差异分布的控制因素。首先,生烃中心控制油气平面分布格局,油气主要富集在生烃中心范围内;其次,坳陷南、北部结构差异决定了各自具有不同的成藏模式,而成藏模式差异是坳陷南、北部油气差异分布的主控因素。坳陷北部以逆冲推覆构造为主,为下生上储、近源短程运聚成藏模式,油气富集在晚期断裂与生烃中心叠合区的上始新统逆冲断背斜;坳陷南部始新统整体呈东倾单斜格局,中始新统因缺乏圈闭条件不易成藏,基底潜山为有利成藏目标,成藏模式为上生下储、侧向运聚。坳陷南部的基底潜山带成藏条件优越,勘探潜力较大。

Barito Basin was an important petroliferous basin in Indonesia,there existed an obvious difference in hydrocarbon distribution,the discovered hydrocarbon reservoirs were distributed in a small area in its north,no oil and gas were discovered in the other areas.Study indicated that the centre of hydrocarbon generation and pattern of hydrocarbon accumulation were the main control factors of its differential distribution.Firstly,oil and gas distribution was controlled by hydrocarbon generation centre,that they were located in the range of hydrocarbon generation center.Secondly,the southern and northern depressions had different constructions,so they had different hydrocarbon accumulation patterns,while the difference of reservoir formation was the main factor controlling the differential distribution of oil and gas both in the north and south.The northern part of depression was dominated by thrust nappe structure,the accumulation pattern was lower-generation and upper storage of hydrocarbon with short distance migration,Oil and gas were enriched in the Upper Eocene thrust anticline in the superimposed zone between late faults and hydrocarbon generation centers.The Eocene in the south of the depression was inclined to the east,the Miocene was not easy to be formed due to the lack of trap conditions,the basement buried hill was the favorable reservoir forming target,the reservoir forming pattern was upper generation and lower reservoir,and the lateral migration and accumulation.Southern depression appears structure of eastern monoclinic pattern,the Mid-Eocene seems to fail to accumulate oil and gas because of lack of trap,but the buried hill is favorable exploration target,its accumulation pattern is upper-generation and lower storage.In the basement buried hill,there exist fine reservoir forming conditions and large exploration potential.