Abstract
An article presents comparative results of pilot of an innovative blocking pack for well-killing operation – emulsion-suspension system with supercharged nanoparticles (ESS). The ESS is characterized by the following competitive advantages: unlimited compatibility with petroleum reservoir fluids, gases, rocks and well-killing brine, adaptability of specific gravity in a wide range (900-1400 kg/m3), foreseeable rheology, alteration of wettability of rock surface, reversibility of blockage, no harm to downhole equipment, system of oil and gas gathering and environment. The ESS blocking pack pilot was carried out in multifractured horizontal wells under high-pressure (39.5 MPa) and high temperature reservoir conditions (115 °C) of Tortasinskoe oil-gas field, Western Siberia, Russia. The reservoir rock of Tortasinskoe oil-gas field is sandstone, characterized by low permeability (0.001-0.0001 μm2) and porosity (13%). A comprehensive laboratory tests program was executed for ensuring successfulness of the ESS blocking pack pilot in the complicated reservoir conditions of Tortasinskoe oil-gas field. The laboratory tests program included a basic research and specific experiments. The results of pilot confirmed significant competitive advantages of the ESS blocking pack in comparison with a synthetic polymer blocking pack, which was unsuccessfully applied earlier on the same production well. The ESS blocking pack showed high performance for well-killing operation in complicated HPHT reservoir conditions than widely used worldwide synthetic polymer system did not work at all.
