Abstract:
Glutenite reservoirs are characterized by complex rock compositions, large grain size variations, poor sorting and strong heterogeneity, which may induce challenges in reservoir productivity evaluation by using physical parameters such as porosity. Since micro-resistivity imaging in different glutenite reservoirs has different features, glutenite reservoir effectiveness was evaluated based on micro-resistivity imaging logging data. Colored images of micro-resistivity imaging logging are converted to gray images through the image processing method. The regression relation between the gray level and the formation porosity can be established by using the Archie formula, and established the heterogeneous characteristic spectrum by conversion. Based on production test data of five wells in the research area, the typical model of heterogeneous characteristic spectrum for Class I, Class Ⅱ and Class Ⅲ reservoirs has been summarized, and found the relationship between heterogeneous characteristic parameters and reservoir productivity as well as the classification standard of reservoir effectiveness. This standard has been applied to the effectiveness evaluation of 10 wells in the concerned area with the coincidence rate of interpretation up to 85.3%. The results showed that the micro-resistivity imaging logging data used for evaluation of glutenite reservoir effectiveness can effectively overcome the difficulties in the evaluation of productivity features for glutenite reservoirs and other highly heterogeneous reservoirs.