Application of superfine and low damage weighting fracture fluid in Yuanba

In order to address the problems of high fracturing pressure and construction difficulties in hydraulic fracturing of tight sandstone gas pools in Yuanba area, a new superfine, low damage weighting fracture fluid was developed specially. In this fluid, the mixed solvent method was mainly used to prepare solid weighting agent with the particle size between 20 nm and 40 nm, then adding 70 g of nanometer particle weighting agent to 100 g base fluid, the fluid density was up to 1.50 g/cm3, which was fully compatible with guar system; after 2 hours shearing at 120℃ and 170 s-1, its viscosity was still as high as 77.5 mPa·s; its damage rate to core matrix was less than 30%, so it was of low damage property. It is simple in technology, low cost, good compatibility and easy to back flow, and its resistance reducing rate was up to about 70%. Field test on continental tight reservoir in Yuanba was fruitful and enjoyed a favorable application prospect for tight reservoirs with high fracturing pressures.