顺8北三维区“串珠”发育特征与油气地质意义

Development characteristics and petroleum geological significance of string beads in 3D seismic region of northern Shun 8 block

塔里木盆地碳酸盐岩储层普遍具有"串珠"状地震反射特征,受断裂-裂缝体系控制作用明显,目前顺8北三维区内断裂对"串珠"分布的控制机制尚不明确。利用储层预测技术、人工厘定及数据挖掘等手段,研究了该工区"串珠"发育特征与分布规律,进一步探讨断裂对"串珠"分布的控制作用。研究结果表明:工区内共厘定304个"串珠",主要分布层位为奥陶系鹰山组下段下亚段—蓬莱坝组上段,NNW向主干断裂控制"串珠"分布密度,距该断裂越近,"串珠"密度越大;深层NE向小型断裂控制"串珠"分布趋势,"串珠"多沿该断裂继承性发育;除主干断裂外,其附近的NNW向次级断裂与NE向小型断裂垂向交汇区为油气有利勘探区域。该研究明确工区走滑断裂的控储作用,可为下一步深层油气勘探及新区勘探提供思路。

Obviously controlled by fault - fracture system, the carbonate reservoir in Tarim Basin generally has the ＂string beads ＂ seismic reflection characteristic. Currently, in in 3D seismic region of northern Shun 8 block, the fault controlling mechanism on the distribution of string beads is not clear. Using reservoir prediction technology, manual determination and data mining methods, the development characteristics and distribution law of string beads in the work area were studied, and the control effect of faults on the distribution of string beads was further dis- cussed. The results show that： 304 string beads were determined in the area, mainly distributed in lower submem- bet of lower member of Yingshan formation and upper member of Penglaiba formation in Ordovician, and the NNW main faults control the distribution density of string beads, which means that the closer the fracture is, the bigger the distribution density of string beads is. In deep layers, NE small faults control the distribution trend of string beads, and the string beads mainly developed successionally along these faults; in addition to the main faults, the vertical intersection area of NNW secondary fracture and NE small faults is the favorable exploration area of oil and gas. The study has clarified the controlling effect of strike slip faults on reservoir in the work area, which can pro- vide ideas for the next deep oil and gas exploration and new area exploration.