Abstract
Massive hydraulic fracturing and re-fracturing jobs have become very popular operations for developing tight oil & gas reservoir and unconventional shale gas reservoir in China. Experiencing long period of production and injection, in-situ pore pressure, stresses and saturation field were significantly changed. Reservoir re-characterization, fracturing modeling and dynamic simulation efforts are necessary to help understand massive re-fracturing impact on production performance and water injection optimization. In this study, a new integrated geomechanics, hydraulic fracturing model and reservoir simulation workflow is formulated and applied to optimize post-frac injection and production in Zhou-6 tight oil block, Daqing field.
With this new workflow, the injection volume of Zhou-6 field was successfully optimized through this more realistic reservoir simulation model. The production of the re-fractured wells was successfully maintained for more than 1 year with the optimized injectivity. The workflow will be widely applicable to other tight oil fields which are involved in massive hydraulic fracturing treatment and water injection development.