Supramolecular Design of High-Temperature-Resistant Tannic Acid and Dehydroabietane-Based Additives for Ultradeep Drilling Fluids

The development of natural high-temperature resistant drilling fluid additives has crucial application value to meet the needs of ultradeep oil and gas exploration. Here, we designed tannic acid-octadecylamine (TA-ODA) and dehydroabietane based butyl sulfonamide (DBS) molecules by introducing Schiff bases, amino groups, and sulfonamides, which exhibit enhanced high temperatures through synergistic multiple weak forces. These compounds demonstrate superior self-assembly ability in solvents, forming functional materials for oil–water systems mediated by hydrogen bonds, π–π stacking, and coordination bonds. Morphological control was achieved by varying the alkyl chain lengths and amide bond types, yielding organogels with lamellae (TA-ODA, DBS), rods (DBS), and three-dimensional network (TA-ODA, DBS) structures. Notably, the tannic acid and octadecylamine-dehydroabietane based butyl sulfonamide (TA-ODA-DBS) complex demonstrated exceptional performances as sustainable drilling fluid stabilizer, maintaining Barite suspension for 72 h at 180 °C, with a breaking voltage >2047 V and a remarkably low settling factor of 0.5026, attributed to precisely controlled weak interactions. This work provides significant advances in high-temperature-resistant and antisedimentation drilling fluid technology.