塔河油田奥陶系碳酸盐岩储层测井识别与评价

Log interpretation and evaluation of the Ordovician carbonate rock reservoirs in Tahe oilfield

塔河油田奥陶系油藏属于多期构造和岩溶作用形成的岩溶缝洞型碳酸盐岩油藏,主要的储集空间是溶蚀的孔、洞、缝,具低孔、各向异性强、非均质性强三大特点,储层的测井识别与评价与砂岩油藏有很大的差别。以岩心标定为基础,总结了成像测井可识别的主要储层类型。在此基础上,研究了各种类型储层的常规测井响应特征及储层的测井识别方法,分析了影响储层判别的各种假储层现象及识别方法。在岩心、成像测井资料标定的基础上,建立了裂缝综合概率模型、双孔介质模型,实现了缝洞型碳酸盐岩储层的常规测井资料定量评价,在塔河油田奥陶系储层测井评价中取得了较好的效果。

The Ordovician oil pools in Tahe oilfield are of karst fractured-vuggy carbonate reservoirs formed by muhiphase tectonic movements and karstificaion. The main reservoir space, composed of pores, cavities, and fractures, is featured by low-porosity and strong anisotropy and heterogeneity. The log interpretation and evaluation of these reservoirs differs greatly from that of sandstone reservoirs. This paper summarizes the main reservoir types that can be identified by FMI logging based on core calibration. It also studies conventional log response characteristics of all types of reservoirs and identification methods of reservoir through log interpretation, and analyzes factors that might affect the identification of reservoirs and methods for differentiating these factors. Based on calibration of core and FMI logging data, the paper presents integrated probability model for fracture and dual porosity model, and realizes quantitative assessment of fractured-vuggy carbonate reservoirs with conventional log data. Positive results have been gained by using them in quantitative log assessment of the fractured-vuggy carbonate reservoirs of the Ordovician in Tahe oilfield.