关键词: 致密砾岩, 缝网复杂程度, 水平井, 压裂模拟

Abstract: A fully coupled hydrodynamic model and field monitoring data are used to reveal the changes in in-situ stress during zipper fracturing in tight conglomerate reservoir under the volumetric development pattern of small well spacing，and the corresponding propagation pattern of fracture network. In the case that horizontal well adopts mono-interval and multi-cluster，staggered fracture arrangement and zipper fracturing，there exist stress interferences between wells and fractures at the same time. A large amount of fluid is injected into the wells fractured first to increase the pore pressure and induce the change in in-situ stress field. The mass and pressure transfer effect of fracturing improves the minimum horizontal principal stress，and reduces the two-way stress difference，which preactively creates geomechanical conditions more conducive to the formation of complex fracture network. The development effect of Mahu volumetric development demonstration zone in Junggar Basin with small well spacing shows that the stimulation effect of intervals subjected to centralized batch fracturing is much better，primary well pattern is more advantageous for the deployment of centralized fracturing and putting into production，and the wells to be fractured later have a more complex fracture network. By reducing the well spacing and conducting zipper fracturing，the horizontal stress difference is reduced continually，and the interferences between artificial fractures are mitigated，which is conducive to the formation of complex fracture network，and can effectively improve the production and recovery factor. 

Key words: tight conglomerate reservoir；complexity of fracture network；horizontal well；fracturing simulation