南海礁灰岩油藏裂缝电阻率成像特征分析及评价

Characters of Resistivity Image in Reef Limestone Reservoir Fracture Evaluation in the South China Sea

流花X-1油藏是在台地边缘上发育起来的生物礁灰岩岩性油藏,为孔隙-裂缝型储层,裂缝和次生溶孔发育。利用随钻电阻率成像测井(GVR)资料对该区裂缝及次生溶孔进行定量评价,据此建立电阻率成像测井裂缝有效性评价标准,并结合实例对该标准进行了验证。结合GVR资料对该区裂缝发育分布规律进行分析,发现该区裂缝在平面和剖面上发育特征有较明显的规律性,裂缝发育程度受局部构造控制,礁核部位主要发育溶蚀缝和孤立缝,礁后部位主要发育成组缝,远离礁核方向,裂缝角度变高,裂缝有效性变好,次生溶孔的发育一定程度上受控于裂缝的发育程度。

LiuhuaX-1 Reservoir was an ecologic reef and reef limestone reservoir was grown on the platform margin,it was a pore-fracture type reservoir,where fractures and secondary dissolved vugs were developed.The data of resistivity imaging logging while drilling was used for quantitatively evaluating it's fractures and secondary dissolved vugs.Meanwhile,the effective fracture evaluation criteria of resistivity imaging logging was developed and proved by examples.According to GVR,the rules of fracture growth and distribution were analyzed.Further research shows that there existed obvious regularity of fracture growth both in horizontal and sectional direction,the fracture growth is controlled by local structure and the dissolved vugs and isolated fractures are grown in the kennel of reef,the fracture combinations are grown behind the reef,the altitude of fracture is high and its effectiveness is good far away from the kennel,while the growth of secondary vugs is controlled by the level of fractural growth to a certain extent.