成像测井资料在礁滩型碳酸盐岩储集层岩性和沉积相识别中的应用——以伊拉克鲁迈拉油田为例

Application of Image logging in identifying lithologies and sedimental facies in Reef-Shoal Carbonate Reservoir——Take Rumaila Oil Field in Iraq for Example

伊拉克鲁迈拉油田M组碳酸盐岩储集层为例,阐述了研究区不同岩石类型及沉积相在XRMI成像测井资料上的响应特征.论文以成像测井资料为主体,通过岩心刻度成像测井并结合GR能谱测井、岩性密度测井和其它常规测井资料识别出粘土矿物、致密灰岩、生物礁灰岩,生屑滩灰岩等岩性;总结了缓坡相、生物礁相、生屑滩相等沉积相的成像测井响应特征,建立了研究区各沉积相的电成像测井相解释图版,并对单井进行了连续的测井相划分.研究表明:M组碳酸盐岩储集层顶部GR能谱测井显示高钍、高钾、高铀含量特征,反应了M组地层在沉积晚期曾暴露地表,形成了风化残余剥蚀面,与上覆地层呈不整合接触关系;M组早期依次发育缓坡相、生屑高能滩相/生物礁相、滩后相和泻湖相,构成了一个完整的下降半旋回.

The M carbonate reservoir in Rumaila Oilfield, Iraq, is studied to describe the response features of various lithologies and sedimentary facies on XRMI image logging. By using core calibrated the image logging and combining the natural gamma ray spectrum logging, litho-density logging and other traditional logging material, this paper had effectively distinguished clay mineral, tight limestone, reef limestone, bioclastic limestone etal. Besides, the image logging response characteristics of sedimentary facies, such as ramp face, reef face, bioclastic shoal face et aZ, had also been summed up. At last, a plate for electrofacies model and the corresponding sedimentary facies had been established and applied on a single well for continuous electrofacies interpretation. The results show that： thenatural gamma ray spectrum response at the top of M formation is high Thorium, high Potassium and high Uranium which indicates that the M formation had exposure to the air at the end sedimentation of M formation, thus formed a unconformable contact with the overlying formation. The lower part of M formation deposited ramp face, high energy bioclastic shoal face, reef face, back shoal face and lagoon face successively, which form a complete regressional sedimentation cycle.