STUDY OF REFRACTURING TECHNOLOGY IN CHANGQING LOW PERMEABILITY OIL RESERVOIR

Fracture opening mechanism was theoretically analyzed,physical simulation test was also conducted to study refracturing phenomenon with Changqing core with achievement that after a pay zone's primary fracturing,original terrestrial stress field would change by the induced stress field caused by the change of pore pressure around fractures and propped fractures,so that new fractures by refracturing would reorient from old artificial fractures,which will penetrate into non-draining area to enhance oil production from those wells unsuccessfully fractured.New fractures generated during refracturing would reorient but the extension direction was still the function of stress status.This paper introduced theoretic calculation and simulation test for new fracture generation during refracturing so as to further stimulate pay zone and serve as a scientific reference for low-permeable oilfields.