Composite stimulation technology for improving fracture length and conductivity of unconventional reservoirs

Unconventional reservoirs have strong heterogeneity, with significant differences in the distribution of porosity and permeability. Fracturing is an important technology for increasing natural gas production unconventional oil reservoirs. For high temperature low permeability, rapid increase acid rock reaction rate leads to a decrease effective distance acidic fluids fracture conductivity, especially inability obtain support at tip, which restricts high-temperature To address above issues, composite fracturing method proposed, first uses proppant crack then gelled corrode middle rear parts crack. According conductivity achievement test experiment migration experiment, when 40/70 mesh ceramsite 100 are mixed mass ratio 1:4, can reach 21.8 μm·cm 2 under closing pressure 60 MPa, 123% higher than cementitious corrosion. The gel used carry ceramsite, Equilibrium level sand embankment 38 cm. At same time, dike formed by different particle sizes ceramic particles smoother vein single size proppant, ability tip better. stimulation has been applied 9 wells carbonate shale After fracturing, 210% that achieved good effects.