Lower Cretaceous. Clear Oilfield Xiagou Logging Sedimentary Microfacies And Reservoir Parameter

Qingxi oil field is located in the south of. the Qingnan depression of the Qingxi seg. which belongs to the area of the Jiuxi basin. It is a large-scale reservoir discovered in recent years with more than 100 million reserves. For the reservoir, Xiagou Formation of Low Cretaceous is the main oil-bearing layer that has been proved by years of production. Because of sedimentary environment is one of important controlling factor to reservoir of clastic rock, it has important value to effectively and timely study and appreciate container rock, including the planiform character of sedimentary microfacies and the corresponding connection sedimentary microfaciesIt with the petrophysical properties of reservoir in this container rock, which is sandshale reservoirs that is formed by the origin of fan-delta and lower energentic environment. At the same time, It is a great challenge for the well-logging to evaluate on such reservoir that has serious anisotropism and shaly sandstone and abundant of pyrite ores, so that it has important practical value to effectively and timely study and conclude one set of logging evaluation technique for such kind of fractured reservoir.The thesis is just from this kind of point of view. It is mainly made of four parts. The first part is of importance, for it will be viewed as the theoretical foundation of the whole work and the main content includes some basic but key theories related to the clastic rock reservoir, such as sedimentary microfacies and logging evaluation, etc. The theories also include the relations between the fractured reservoir and the logging response and introduce some research results by the former experts in the sedimentary facies and logging evaluation filed. At the end of this part some mathematical methods will be introduced, including the regression approach, Artificial Neural Networks, etc. The second part is also the key content of this thesis, which is composed of the 4^rd chapter, the5^th chapte. Some basic information related to the studied area will be introduced at 3rd chapter. And then combined with the practical conditions of the studied clastic rock reservoir, the thesis has analyzed and demarcated sedimentary microfacies firstly, and has explored and established the model of logging-sedimentary microfacies using the method of peinciple component analysis and the character of core. The third part of is also the key content this thesis, which is composed of the 6^rd chapter. Aiming at clastic rock reservoir combined with the practical conditions of Qingxi oil field, this thesis studied the norm of identifiable reservoir through conventional logging, and set up the parameters calculation models such as porosity, water saturation and permeability which using Back-propagation Network and the regression approach, solved the question which are uncertainty and veracity in parameters calculation are resulted by difficult choose parameters calculation of mud and can not indicate the content of mud by GR, and which are low accuracy of fissure's parameters calculation which on account of dual laterolog. This chapter has also analyzed the method of the fluid property identification through logging method in this complex clastic reservoir and propound P^1/2 fluid property identification for Qingxi oil field. The forth part of is the key content this thesis also, which is composed of the 7^rd chapter. In this chapter. This thesis is attempt to set up the type of this reservoir, and to probe and study the corresponding connection sedimentary microfacieslt with the physical properties of reservoir in this container rock, and point to favorable reservoir which is frontsubwater channel microfacies and favorable position of structure.