Logging Evaluation Study On Fractured-reservoirs Of Zhuangxi Paleozoic Buried Hill

Fractured reservoirs have many peculiarities. In terms of their physical-lithological nature and mud filtrate invasion depth of the pore side, there are significant differences and uneven nature of section plane. With the existence of cracks and cavities of different cracks, there are the large range of changes and uncertainty to the sound, radioactivity and electricity characteristics of rock. Therefore, the identification and development of fractured reservoir possesses some certain degree of difficulty. In-depth study and quantitative evaluation of fractured reservoirs is necessary.Zhuangxi oilfield is fractured oil deposit of the metamorphic rocks buried hill. The reservoir has the characteristics of complex lithology, reservoir complex media types, difficulty of effective reservoir parameter identification and determination of reserves parameter. Therefore, identifying reservoirs and determining the dual porosity reservoir parameters with well-logging information, is the key technologies of the reservoir evaluation in the study area. In order to solve this bottleneck technology, this paper studied the identification of cracks in buried hill and reserve parameters.For the research of development of fractured reservoirs in the area, the influencing factors have been studied and analyzed using the ideas that the conventional logging were calibrated by imaging logging as correction. In order to obtain correct fracture porosity parameters, the crack Index parameters must be determined by the porosity curve area-weighted average of the statistical method. And then the method of calculating effective porosity, saturation, and reservoir permeability has been studied. The quantitative calculation of fractured reservoir parameters has been achieved. On the base of comprehensive study of the reservoir, the reservoir is divided into three levels: Ⅰclass,Ⅱ class and Ⅲclass, and Ⅰ class reservoir is the best one with the highest oil and gas production.The method of the paper has been applied by practical application in Zhuangxi Paleozoic buried hill area, proving the applicability of fractured reservoirs. Through the analysis of fractured reservoirs in the study, the paper gives ideas and methods, providing an explanation process, so that interpretation is consistent with the rate of markedly improved, to achieve the expected goal, and providing ideas and methods for the future conduct of other oilfield well logging interpretation of fractured reservoir study.