DG油田油气层高侵实例分析  

Case Study on Resistive Invasion in an Oil-gas Zone

作　　者：黄龙[1] 鲍志东[1] 刘俊东[2] 邵维志[2] 蒋宏修[2] 李玉泉[2] 

机构地区：[1]中国石油大学,北京102249 [2]大港油田集团测井公司,天津300280

出　　处：《测井技术》2007年第6期559-562,共4页Well Logging Technology

摘　　要：淡水泥浆钻井时,阵列感应测井曲线在水层段通常显示高侵特征,在油层段显示低侵特征.但井况复杂时油层段也可能高侵.DG油田MX1井32、33、37、38号层的阵列感应测井曲线都表现出明显的负差异,这是典型的水层高侵特征,故初次解释都定为水层.但其中32号层试油验证结果却是油气层.分析后认为:在井况差、泥浆比重大的情况下用淡水泥浆打井,由于泥浆对油层段的侵入超出阵列感应电阻率的最大探测深度,实际测量的只是淡水泥浆侵入带,如不予以识别就会导致油气层漏评.32号层的第2次10～90 in阵列感应电阻率测井值明显高于第1次,这就是地层水进一步被淡化的高侵特征的表现.Array induction logging in wells drilled with fresh water mud usually shows character of resistive invasion in water bearing zones whereas shows character of conductive invasion in oil bearing zones.Nevertheless there might be resistive invasion in oil bearing zone in complex bore condition.All array induction logs in 32-,33-,37-and 38-layer of well-MX1 in DG Oilfield obviously showed negative diversity.It is a typical character of water zone,so that all the layers were firstly interpreted as water zones.However,well test did verify that the 32-layer among them is an oil-gas zone.Cognition based on analysis is that: While drilling with high density fresh mud in bad well condition,since the invasion radius has been greater than the maximum investigation depth,what the logging tool practically measured is merely the invasion zone,false identification on this situation will cause oil-gas zone to be lost in interpretation.The phenomenon that the resistivities measured in second logging by 10～90 in array induction logging are obviously greater than that in first logging is also a character of resistive invasion where the formation water has been keeping on being diluted.

关 键 词：石油测井 淡水泥浆 泥浆侵入 油气层高侵 测井曲线 

分 类 号：P618.13[天文地球—矿床学]