摘要
尼日尔三角洲盆地是世界上重要的富含油气盆地之一，油气储集于阿格巴达组砂岩中。按“砂岩识别一含烃层识别-油气层及油气水界面识别”的研究思路，在尼日尔三角洲大量油气田实际资料综合研究的基础上，总结出了一套简单可行的该三角洲油、气层及油、气、水界面的测井识别方法。岩性的识别立足于自然伽马，正常砂岩的自然伽马值相对于基线的降低幅度大于40API，一般在60～100API之间。储层含烃性的识别立足于深侧向电阻率。在阿格巴达组上段砂岩中，含烃层深侧向电阻率一般大于10Ω·m，在中段和下段砂岩中，含烃层深侧向电阻率大于3Ω·m，一般大于5Ω·m。岩石总密度可以识别出合烃层和致密干层。中子孔隙度是从含烃层中识别出油、气层的主要指标，油层的中子孔隙度大于20％，一般为20％～40％；而气层的中子孔隙度小于20％，一般为5％～15％。
Niger delta basin is the world's most important oil and gas-rich basins,oil and gas accumulated in sandstone of Agbada formation. After the integrated analysis of basic ge-ologic data from oil and gas fields of Niger delta,a simple but practicable method is developed to identify oil and gas through well log data,which is based on the route of identification of sands-identification of hydrocarbon-identifi-cation of oil and gas,and gas oil contact (GOO and water oil contact (WOO. Gama ray can be used to identify sands from mud or shell,with negative value to the mud base line of more than 40 API (typically 60-100 API) for sands. Deep resistivity can be used to identify hydrocarbons fromwater,with the value of over 10 ohmm for hydrocarbons in the Upper Section of Agbada Formation,and the value of o-ver 3 ohmm (typically over 5 ohmm) for hydrocarbons in theMiddle and Lower Sections of Agbada formation. Bulk density can be used to identify hydrocarbons' from tight dry sands. Neutron can be used to identify gases from oils,withthe value of below 20 pu (typically below 5-15 pu) for gases while with the value of over 20 pu (typically below 25-40 pu) for oils.
出处
《石油地质与工程》
CAS
2010年第1期52-55,共4页
Petroleum Geology and Engineering
关键词
尼日利亚
尼日尔三角洲
油层
气层
油气界面
油水界面
测井
Nigeria
Niger delta
oil layer
gas layer
gas oil contact (GOC)
water oil contact (WOC)
well log
