海拉尔盆地贝尔凹陷布达特群潜山储集特征及控制因素

Buried hill of Budate Group in the Buir Sag,Hailar Basin:Reservoir characters and its controlling factors

综合利用岩心、测井、录井和生产测试等资料,对海拉尔盆地布达特群潜山的储集特征进行了深入研究。结果表明:研究区潜山的储集类型可划分为溶蚀风化壳型和裂缝破碎带型2种基本类型,前者主要受古暴露期大气水淋滤作用的控制,溶蚀作用随与不整合面距离增大而减弱;裂缝破碎带型储层主要受断层性质的控制。古地貌恢复结果表明:贝尔凹陷布达特群在兴安岭群沉积之前具有东高西低的总趋势,与现今潜山顶面构造图比较,有古高今低、古今均高、古低今高和古今均低4种情形,前两种情况更有利于形成溶蚀风化壳型储层。布达特群潜山发育多期裂缝,裂缝发育程度和产状与断层有很好的相关性,通过钻井资料预测,苏德尔特潜山带为裂缝发育区。

The reservoir characteristics of buried hill of Budate Group in the Buir Sag, Hailar Basin, were studied by comprehensive utilization of lithology, well logging, production testing and other related data. The reservoir of buried hill in the region was divided into two kinds of basic types：solution weathering crust reservoir and the fracture reservoir. The former was mainly af- fected by atmospheric water leaching in the palaeoexposure period. The dissolution became weaker as the distance increased from the unconformity. The fracture reservoir was mainly con- trolled by faults. According to palaeogeomorphology reconstruction results,the general trend of the Buir Sag was that the east part was higher than the west part before Xing＇anling Group was deposited. Comparing the palaeogeomorphologic map to the present structural map of the top of the buried hill, four kinds of situations could be discovered： higher in ancient and lower in modern, higher in both ancient and modern, higher in modern and lower in ancient, lower in both ancient and modern. The former two conditions were more advantageous to formation of solution weathering crust reservoir theoreticaly. Multiphase fracturing were developed in Budate Group buried hill and there had a good correlation between the degree of fracture development and faults. Drilling revealed the Suderte buried hill belt being an area of fracture well developed.