Logging Description and Quantitative Evaluation of Fractures in Deep Carbonate Reservoirs in Tarim Basin
摘要
Fractures are the main seepage channels and storage spaces of fractured-vuggy carbonate rocks, and their accurate description has great significance to the classification and evaluation of reservoirs. The well logs response characteristics of fractures under different well types are different, and the evaluation methods are different as well. In vertical wells, continuous core and logging data are obtained to accurate calculation for parameters such as fracture length, width and thin section porosity after calibration, by drilling ground-coring scientific exploration wells. The combination of array acoustic logs and micro-resistivity image logs are used to evaluate the effectiveness of fractures and connectivity of pore systems. For horizontal well reservoir fracture evaluation, through the establishment of fracture logs response characteristics chart, the relationship between fractures, formation and wellbore is analyzed, thus the technical support is provided for the construction of horizontal wells in the long open-hole section. For evaluation of borehole side fractures, optimization of remote detection acoustic logging data processing algorithm, clear image of borehole side fracture reflectors, and establishment of borehole side fractures description and evaluation methods. The application of the above logging technology has realized the fine description and evaluation of fractures, from the borehole to borehole side under the different well types. It provides an important basis for the optimization of oil testing schemes for fractured-vuggy carbonate reservoirs.