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.