Advantages
• Thermal stable up to 500°F.
• Controlled water and oil solubility to effect best chemical and physical performance.
• Readily disperses in water and oil fluids.
• Extremely temperature stable – does not have the softening point typically associated with naturally occurring asphalt.
• When the temperature reaches more than 150°C, the sulfonated asphalt product will partially sublimate, but at higher temperatures, after one hour, the weight loss will remain within 10%.
• Sulfonated asphalt has unique properties, including the reaction with shale to inhibit shedding and swelling, reduce high temperature and high pressure filtration loss, form thin and compressible filter cake, improve lubrication performance, etc.
• The stable clay properties of sulfonated asphalt can reduce the fluid loss and downhole torque friction, and solve the lubrication problem.
In order to improve the broad - spectrum plugging effect and high - temperature stability, a high - performance high - temperature - resistant plugging agent for oil - based drilling fluids must meet three conditions: First, the plugging agent has good high - temperature stability and does not aggregate in the oil - based drilling fluid. Second, the plugging agent should have adsorption groups and long carbon chains, a high oil - soluble substance content, and possess both chemical and physical plugging capabilities. Third, the particle size distribution of the plugging agent should be wide to improve the ability to plug fractures of various widths.
