Daqing oilfield has been produced for more than 50 years. Oil production from conventional oil pools is dropping significantly. But in recent years, massive fracturing technology were applied to difficult tight oil reservoir and unconventional gas development. More and more difficult reserves can be unlocked with this technology and that will revive oil production in Daqing field in near future, because the estimated recoverable tight oil & gas is more than conventional oil produced in past 50 years. To develop these tight oil reservoirs such as Zhou-6 and Shu-2, water injection and re-frackstimulation are required to provide economic production rate for running field under low oil price market environment.

Ageneric workflow combining reservoir qualities and engineering parameterswas proposed in this paper. The advantage of this new workflow can consider all aspects and interactions from historic reservoir pore pressure, saturation and stress to frack pumping schedule, fluid and proppant volume which will impact re-frack fracture network development in great detail and production behavior of re-frack well in an integrated model and simulation process. At the same time, how varying well spacing and injection schema impact the fracture complexity and stimulated reservoir volumeof massive re-frack stimulations.

This case study concludes that an integrated new workflow from reservoir characterization, geomechanics analysis, stimulation engineering to history matching with calibration of micro-seismic data and production performance data is possible and feasible to precisely simulate re-frack wells production behavior under varying well patterns and water injectivities.

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