Property Evaluation and Field Application of Dry Powder Friction Reducer

Ordos Basin in China is rich in coalbed methane (CBM) resources, where the stimulation strategy of “large fluid volume, large sand volume, and high displacement rates” has achieved favorable results. However, due to the strong adsorption of coal reservoirs and massive fluid consumption, conventional emulsion and suspension fracturing fluids face challenges such as severe formation damage, transportation difficulties, and high costs. To address these issues, a dry powder friction reducer and continuous mixing process were developed. Laboratory tests on the dry powder friction reducer's performance were conducted and applied in two CBM wells. Results show that viscosity can be adjusted in real time by varying friction reducer dosage to meet high-viscosity sand-carrying requirements. At 0.3% dosage, the dry powder achieved 20-s swelling time with viscosity reaching 53.5 mPa s, while post-gel-breaking fluid viscosity dropped to 2.1 mPa s. Under 100 s−1 shear rate for 120 min, the final viscosity remained at 53 mPa s. The friction reduction rate of different viscosities averaged over 65% at 10 m3/min rate displacement. Compared to conventional emulsion or suspension systems, the dry powder friction reducer reduced formation damage by 30–50% by eliminating pore throat and micro-fracture blockages caused by organoclay, suspending agents, dispersants, and emulsifiers. Field applications in two wells demonstrated viscosity exceeding 45 mPa s at 0.25% concentration during operations, meeting sand-carrying requirements. Post-fracturing flowback fluid viscosity measured 1 mPa s, with average daily gas production exceeding 20,000 m3. This research provides technical support for further cost reduction and efficiency improvement in CBM hydraulic fracturing treatments.