基底潜山型火山岩储层裂缝综合评价——以克拉玛依油田四2区火山岩为例

Comprehensive Assessment of fractures in the volcanic Basement Buried Hill Reservoirs:A Case Study of Volcanic Reservoir in 4-2 Region of Karamay Oilfield

克拉玛依油田四2区石炭系油藏为典型的基底潜山型火山岩油藏,为了明确石炭系火山岩储层裂缝发育特征以及分布规律,综合运用岩心、薄片、测井、实验等资料对储层裂缝特征进行了研究,利用3种不同的方法对裂缝纵向上和平面上分布情况进行综合预测。结果表明：四2区石炭系火山岩储层裂缝类型包括构造裂缝、风化缝、成岩缝以及构造—风化缝,以构造裂缝和风化缝为主;裂缝延伸主要在10~30cm之间,裂缝倾角大,以30°~60°和〉80°为主;岩心裂缝平均密度为10~15条/10cm。裂缝综合评价表明：纵向上,裂缝发育段多距石炭系顶部古风化壳30~150m,平面上,裂缝发育的有利区主要分布在Ke114井—J354井—J353—J352井区、J153井区、J45井断裂两侧、J332井—J324井—J336井—J340井区向北到克—乌断裂一带。

The Carboniferous volcanic reservoir of 4-2region in Karamay Oilfield is a typical volcanic basement buried hill volcanic reservoir.In order to demonstrate the fracture characteristics,and distribution rule of the Carboniferous volcanic reservoir,cores,flakes,well-log data,and other experimental materials are used to study the fracture characteristics.Three different methods are used to comprehensively predict the distribution of fractures on the longitudinal and on flat surface.The results show that the fracture types in Carboniferous volcanic reservoir of 4-2region include tectonic fracture,weathered fracture,diagenetic fracture and structure-weathering fracture and tectonic fracture.Weathered fractures are the dominant fractures;fracture extendency is mainly between 10 cm and 30cm;fracture dip is big and is dominated by 30°-60°and greater than 80°.The average density of core fracture is 10-15strips/10 cm.The comprehensive evaluation of fractures showed that：On the longitudinal,fracture development segments are mainly located in the area about 30 to 150meters below the ancient weathering crust of top Carboniferous;on the flat surface,the advantageous fracture growth area distributed in the well areas of Ke114-J354-J353-J352,J153,both sides of J45 fault,from the well area of J332-J324-J336-J340 to the north Ke-Wu fault.