裂缝型储层流体类型识别技术——以辽河盆地大民屯凹陷中—新元古界潜山储层为例

A Method of Identifying Fractured Reservoir Fluids:A Case of Mesoproterozoic-Neoproterozoic Buried-hill Reservoirs in Damintun Sag,Liaohe Basin

裂缝型储层流体类型识别一直是国际测井界急待解决的难题。在对流体类型影响因素分析的基础上,采用三种识别流体类型的方法,即核磁共振测井法、常规测井法和产液剖面法,在辽河盆地大民屯凹陷中—上元古界潜山储层流体类型的识别中,取得了良好的地质应用效果,识别的符合率达到了88%。理论研究和实际应用结果均表明,在地层有效孔隙度适宜的情况下,应用核磁共振测井识别流体性质的效果比较直观和明显,核磁共振测井应用于裂缝型储层流体类型识别是有效和可靠的。对于常规测井,认识到不同流体类型与电阻率比值的高低、粘土含量的多少以及孔隙度的大小等密切相关,并提出了综合这三项因素的流体类型识别参数 FTI。FTI 接近于0,代表干层;FTI 接近于1,代表油层;低产油层的 FTI 值介于油层与干层之间。实践表明该参数应用效果良好。产液剖面法可与前两种方法配合使用,相互印证。

Attentions have been paid to reservoirs with complex litholo- gy in exploration of carbonate and volcanic reservoirs in some oilfields.Identification to types of fluids within fractured reser- voirs is still an unsolved problem for logging in the world.The reason why the types of the fluids are difficult to identify is to result from complex lithology,various types and heterogeneity of reservoirs associated with them.In this research,on the ba- sis of analysis of influence factors of reservoir fluids,three methods to identify fluid types were brought forward,that is, the nuclear magnetic resonance (NMR) method,the regular well logging method and the production logging method.Good effects that revealed a coincidental ratio of identified correla- tion up to 88% were made by applying these methods to the i- dentification of fluids within Mesoproterozoic—Neoproterozoic Buried hill reservoirs of metamorphic and carbonate rocks in Damintun Sag of Liaohe Bsin,Which have indicated that NMR technique applying to identify fluid type is effective and relia- ble.It is known that fluid types are correlated to the ratio of deep and low laterolog resistivity,ciay content and porosity. A parameter of the fluid type identification (FTI) is put forward here,and obvious geological effect is obtained.When FTI ap- proaches to 0,it means a dry bed and when it is near to 1,it does an oil bed.The value of between 0 and 1 indicates low- yield oil bed.