泾河油田三叠系长8段天然裂缝特征与预测

Characteristis and Prediction of Natural Fractures in Triassic Chang-8 Member,Jinghe Oilfield

据野外露头、岩心和FMI测井等资料分析认为,鄂尔多斯盆地泾河油田三叠系长8段天然裂缝主要为垂直裂缝和高角度斜交裂缝,裂缝走向主要为北东—南西向。裂缝主要在砂岩岩层内发育,穿层裂缝较少,裂缝充填程度低,大多为开启缝,有效性较好。天然裂缝发育程度主要受岩性、构造变形和断层等因素控制,其中断层是主要因素。天然裂缝分布预测表明,泾河油田东部泾河17井区和西部泾河2井区为裂缝发育区,同时储集层砂体较厚,开发潜力较好;中部和北部地区裂缝较发育,开发潜力次之,预测结果与实际生产数据吻合较好。

Through analyses of outcrop,core and FMI logging data,it is considered that vertical fractures and high-angle oblique fracturesare the dominant natural fracture types in Triassic Chang-8 member of Jinghe oilfield in Ordos basin.These fractures are mainly NE-SWtrending,which are mainly developed in sandstone reservoirs with a few strata-penetrating fractures and relatively low filling.Most frac-tures are open with relatively good validity.The development of natural fractures is mainly controlled by lithology,structural deformationand fault,and the fault is the main factor.The prediction result of natural fracture distribution shows that the fractures are best developedin Wellblock Jinghe-17 in eastern Jinghe oilfield and Wellblock Jinghe-2 in western Jinghe oilfield,and the sandbodies in the reservoir arethick with relatively good development potential; fractures in the middle and northern parts of the region are relatively developed with sec-ondary development potential.The prediction results are well matched with the actual production data.