A non-cross-linked CO2 foam fracturing fluid with low friction

The hydrophobic associating polymer (MXN-1) was used as a foam stabilizer with optimized supporting additives to solve the problem of high friction in foam fracturing fluid. The basic formula was 0.3% MXN-1 + 0.08% sodium dodecyl sulphate (SDS) + 0.3% B-14 + 1% potassium chloride (KCl) + 0.03% ammonium persulphate (APS). The friction reduction, sand-carrying capacity, gel-breaking performance, and core damage of the fracturing fluid system were studied. The results showed that the proposed system had a unique friction reduction advantage compared with the cross-linked guar gum foam fracturing fluid, and the friction reduction percent reached 62% at a high flow rate. The surface tension of the gel breaking solution was lower than 25 mN/m, and the residue content was about 7 mg/L.