Refined Reservoir Description In Middle-City Zone Of Fuyu Oilfield

Fuyu oilfield is a middle-permeability and fractured sandstone reservoir. Now, it already enters a high water cut exploitation period. The composite water cut is more than 88%, and the oilfield faces a severe exploitation condition. In this period, the distribution of remaining oil is very complex, and presents a highly disperse state. The oilfield needs urgently a refined reservoir description research to direct the development and regulation, to provide geologic foundation for overall system adjustment. Wherefore, the refined reservoir description research is urgently to be developed.The thesis reached the middle-city zone of Fuyu oilfield in Jilin oilfield, developed a refined reservoir description by sticking closely to the problems need to be settled urgently in development and regulation, finely descripted the features and law of the reservoir from fine sublayer correlations, conformational study, depositional microfacies study, reservoir heterogeneity study, single sand-body distribution study, 3D geology modeling, etc.The following achievement was obtained by the research:(1) It was considered that the study area is an arched structure with several high points after conformation research. There are 4 groups and 13 layers in the FuYu oilfield. The thickness of layers changes very little. And this reflects a stable sediment.(2)Throughing depositional microfacies study, it is considered that the study area is a deltaic deposition, including 2 intrafacies( delta plain and delta front) and 14 microfacies.(3). throughing the reservoir heterogeneity study, including the substage boundary of channel surface (the boundary of single sand-body), the distribution characteristic of interbeds in sand groups and insulating layers in layers, vertical connection were considered.(4). The new calculation method of saturation in water flooded layer was raised on the basis of new wells'production status, and qualitative analysis of corresponding logging curves'shape, including Acoustic wave and Resistivity logging curves. And 42 new wells were interpreted by the method.(5). The main control factors of remaining oil distribution was analysised on the basis of the interpretation result of water flooded layer, production profile, injection profile, the relationship of logging interpretation, sedimentation, structure, single sand-body.Researching the reservoir of study area, the foundation of the oilfield's development measure is more sufficient. The development level is raised and development effect is improved, economic benefit is raised, a contribution is made to the development of Fuyu oilfield. In addition, Fuyu oilfield is one of the longest development time and largest size middle-low permeability and fractured sandstone reservoirs. The proportion of this type of reservoir is large in our country, so, this thesis has an important effort to rational development of the same type reservoirs in our country.