Abstract: To address the difficulties in quantitative prediction of the development, spatial distribution and size of fractures in dense reservoirs in Well Block Ma 2, Northwest Margin, Junggar Basin, the size and spatial distribution of fractures were predicted quantitatively and the results were verified with Petrel's Kinetix fracture simulation module and numerical simulation technology based on crustal stress field, on the basis of analysis on fracture characteristics with cores, slices, imaging logging and other data. The results of the study showed that, the fractures in Well Block Ma 2 were dominated by shear fractures with a density of 5-6 fractures/m and gradually extended to the wings, and the fracture aperture was 0.00 to 0.20 mm; the fracture distribution in Well Block Ma 2 was significantly heterogeneous in longitudinal and planar direction, the fracture-concentrated sections alternated with the fracture-undeveloped sections, and fractures were well developed around most of fault zones. It is more reasonable to characterize the spatial distribution characteristics, such as length and width of fractures, with the microseismic monitoring data of horizontal wells and the results of fracture simulation. The study results provide an important basis for the implementation and optimization of development schemes for Well Block Ma 2, Mahu Oilfield.

Key words: tight reservoir, fractures, stress, geological model, quantitative prediction, Well Block Ma 2