PRACTICE OF LARGE-SCALE SAND FRACTURING AT BAJIAOCHANG GASFIELD IN THE SICHUAN BASIN

The Bajiaochang gasfield in the Sichuan Basin is a low-permeability, low-porosity high pressure gas field, with thick sand bodies and low reservoir abundance. Large-scale sand fracturing is an effective technology to develop this gas field. But challenges still exist. On one hand, there are two difficulties to be solved. One is high flow rate required to ensure proppants effectively pumped into the pay zone; the other is long operation time needed due to large scale of the operation. On the other hand, the effective large-scale sand fracturing requires optimum reservoir formation, fracturing fluid and techniques, and systematic control of the fracturing quality. The Well Jiao-X is taken as an example to make analysis on reservoir condition, fracturing test, optimization design and quality control, so as to ensure success and high quality of large-scale sand fracturing to optimize ROI ratio.