Russian scientists from Perm Polytechnic (PNRPU), together with colleagues from China and Saudi Arabia, have developed a gel capable of sealing drilling fluid leaks directly during well drilling. The material remains fluid long enough to pass through the equipment, and then, under the influence of temperature, turns into a strong polymer directly in the damaged area.
The problem arises when drilling fluid escapes through cracks and voids in the rock. To eliminate the leak, it is usually necessary to stop work and inject an isolating compound. The new material should change this due to controlled hardening.
The development is based on an aluminum compound that turns into a polymer, and zinc oxide. The latter acts as a kind of protective shell: at low temperatures, it prevents the active component from reacting too early.
In a deep hot well, the bonds between the components gradually break down, and the gel begins to harden. In experiments, it remained fluid for more than 2 hours, and complete hardening took about 3 hours.
Tests showed isolation efficiency above 90%. In terms of strength, the material is 1.5 times superior to analogues and can operate at temperatures up to 120 °C, while many existing compositions are designed for 80–90 °C.
The developers expect that the technology will reduce drilling fluid losses and the number of forced shutdowns during the construction of deep oil and gas wells.