The leading factors of nanophenomena in geological formations, fields fluids and production equipment were established for oil and gas recovery, as well as technologies of their regulation (nanotechnologies). Some ways for in-creasing of oil-and-gas recovery are described: regulation of injected reagents ionic component, influence on the oil-and-gas layers by physical fields resulting in change of balance in system «oil-gas-water-rock», and others nanotechnol-ogies which use for increases efficiency of oil-and-gas reserves operation (in-clude gashydrate). The analysis of the nanomineral complexes geometry change in oil forma-tion is carried out. Our studies reveal that the control of the above nanocom-lexes can increase oil recovery of oil field due to change of the capillary hyste-resis value. Examples of some ?OR/IOR-nanotechnologies efficiency estimations are given. This book could be used for study geological and physical-and-chemical problems, and profitability calculation of oil-and-gas recovery.