Logging Quantitative Evaluation Method of Sweet Spot Parameters in Continental Shale Oil and Its Application
The continental shale oil reservoirs in China are divided into three types according to their sedimentary characteristics and hydrocarbon accumulation relationships:interbedded type,mixed type,and clay lineation type.Furthermore,considering the dominant control factors and associated development challenges,these reservoirs can be subdivided into five categories:complex structural influence type,highly heterogeneous reservoir type,high clay modification difficulty type,high viscosity oil flow difficulty type,and low oil saturation type.The primary control factors influencing high yield and stable production vary significantly across different reservoir types;thus,a detailed characterization of sweet spots in both horizontal and vertical dimensions—along with an understanding of enrichment patterns and distribution characteristics—is crucial for large-scale efficient development.In this paper,by establishing the calculation model of mineral composition,porosity,mechanics and brittleness,integrating with data from vertical well tests and dynamic production from horizontal wells,and optimizing the main control factors and core parameters of different types of reservoir productivity,the classification and evaluation criteria of sweet spots are established for its selection in reservoir.Comprehensive analysis indicates that high-quality sweet spots in continental shale oil predominantly occur within middle to high total organic carbon(TOC)backgrounds characterized by significant pore development as observed through nuclear magnetic resonance techniques along with effective fracture networks(Fracture development).These areas also exhibit favorable cap rock sealing conditions.The findings have been extensively applied in target window selection and drilling monitoring of horizontal wells across multiple oilfields,providing theoretical guidance and technical support for shale oil exploration and development.
continental shale oilsweet spotmineral contentporositybrittleness indexhorizontal well target window
NETL
NSTL
万方数据
