Development and Application of Anti-collapse & Anti-drag Agent for Drilling Fluid

Using asphalt as raw material, anti-collapse drag reducing agent GFT with softening point at 35 °C is preparedby employing interfacial complexes generation method. The rheological properties and lubrication are measured before and after adding GFT in several water-based drilling fluids. The results show that GFT exhibits the excellent anti-caving and lubricity performance. And GFT could deform into and cement fracture at lower temperature, and then seal off cracks of sidewall, reduce the drilling fluid filtration. When the dosage of GFT is 0.5 wt.%, the lubricity coefficient reduced rate of bentonite dispersion is 80.5%. In addition, GFT shows better lubrication performance and effect of reducing filtration loss than commercially available products in the same dose (2 wt.%). Eventually, through field application of GFT in Jinchang JCSD-1 borehole and Handan ZK10-2 borehole, the results indicate problems of wellbore collapse and lubricity of drilling fluid have been solved successfully. Consequently, anti-collapse drag reducing agent GFT has a promising potential application for drilling fluids.