Abstract: Oil and gas recovery includes selecting a previously used oil or gas containing layer in which cumulative perforation was utilized, closing micro cracks over a thickness of the oil or gas containing layer, carrying out slotting of the oil or gas containing layer to form slots, producing micro cracks over the thickness of the oil or gas containing layer, carrying out hydraulic fracturing of the oil or gas containing layer, and withdrawing oil or gas from the oil or gas containing layer with maintaining of a pressure in the well.

Abstract: Oil and gas recovery includes selecting a previously used oil or gas containing layer in which cumulative perforation was utilized, closing micro cracks over a thickness of the oil or gas containing layer, carrying out slotting of the oil or gas containing layer to form slots, producing micro cracks over the thickness of the oil or gas containing layer, carrying out hydraulic fracturing of the oil or gas containing layer, and withdrawing oil or gas from the oil or gas containing layer with maintaining of a pressure in the well.

Abstract: A method of oil and gas recovery from previously used oil or gas containing wells includes selecting at least two previously used oil or gas wells located in an area of a same oil or gas containing layer and designating one the previously used oil or gas wells as a production well and another of the previously used oil or gas wells as an injection well, cutting in the injection well slots which communicate the injection well with the oil or gas containing layer, injecting a fluid into the injection well after cutting the slots in the injection well to increase a pressure in the production well, and subsequently recovering oil or gas from the production well.

Abstract: Oil and gas recovery includes selecting a previously used oil or gas containing layer in which cumulative perforation was utilized, closing micro cracks over a thickness of the oil or gas containing layer, carrying out slotting of the oil or gas containing layer to form slots, producing micro cracks over the thickness of the oil or gas containing layer, carrying out hydraulic fracturing of the oil or gas containing layer, and withdrawing oil or gas from the oil or gas containing layer with maintaining of a pressure in the well.

Abstract: Oil and gas recovery includes selecting a previously used oil or gas containing layer in which cumulative perforation was utilized, closing micro cracks over a thickness of the oil or gas containing layer, carrying out slotting of the oil or gas containing layer to form slots, producing micro cracks over the thickness of the oil or gas containing layer, carrying out hydraulic fracturing of the oil or gas containing layer, and withdrawing oil or gas from the oil or gas containing layer with maintaining of a pressure in the well.

Abstract: A method for increasing productivity of oil and gas wells includes carrying out a secondary opening in formations which were opened before, by first using a hydro-sandblasting operation and thereafter using a hydro-fracturing operation.

Abstract: For increasing productivity of oil, gas and water wells, a horizontal or inclined well is excavated, a plurality of cavities are formed transversely to the direction of elongation of the well so as to provide partitions between them, and hydrocracking is carried out to act on the partitions between the cavities.

Abstract: For increasing productivity of oil, gas and water wells, a horizontal or inclined well is excavated, a plurality of cavities are formed transversely to the direction of elongation of the well so as to provide partitions between them, and hydrocracking is carried out to act on the partitions between the cavities.

Abstract: For increasing productivity of oil, gas and water wells, a horizontal or inclined well is excavated, a plurality of cavities are formed transversely to the direction of elongation of the well so as to provide partitions between them, and hydrocracking is carried out to act on the partitions between the cavities.

Abstract: A method of increasing productivity of oil, gas or water wells, includes the steps of excavating of a horizontal or inclined well, forming in the horizontal or inclined well a plurality of cavities which extend transversely to the direction of elongation of the horizontal or inclined well and are spaced from one another in a direction of elongation of the horizontal or inclined well so as to form a plurality of partitions therebetween, providing packing in the horizontal or inclined well by packers, and executing hydrocracking by acting onto the partitions located between the cavities inside the horizontal or inclined well.

Abstract: A method of treatment and perforation of a near-well zone of oil and gas recovery wells, includes making an oil or gas recovery well in deposits with carbonate collectors, performing slotting opening by sand treatment with a jet containing sand and a sand carrying liquid, and using as the sand carrying liquid a sand carrying liquid which contains light hydrocarbons C3-C12.

Abstract: In a method of evaluation of deposits and opening of productive formations in recovery of oil or gas, a previously drilled well is located and investigated to determine at least one first zone which is not productive for oil or gas extraction and at least one second zone which is productive for oil or gas extraction; the at least one first zone which is not productive for oil or gas extraction is skipped, while hydroslotting is performed in the at least one second zone by making a plurality of slots and thereby producing unloaded regions so as to provide again a flow of oil or gas in the previously drilled well which was not in operation.

Abstract: A method of increasing productivity and recovery of wells in oil and gas fields includes determining a direction of maximal horizontal stresses, producing at least two wells so that they are spaced from one another in a direction corresponding to the direction of the maximum horizontal stresses, forming in at least one of the wells at least one vertical slot oriented substantially from the at least one well to the other of the wells, and introducing a hydrofracturing fluid at least into the at least one well to produce a hydraulic fracture in direction from the at least one well to the other well.

Abstract: A method of increasing productivity and recovery of wells in oil and gas fields includes determining a direction of maximal horizontal stresses, producing at least two wells so that they are spaced from one another in a direction corresponding to the direction of the maximum horizontal stresses, forming in at least one of the wells at least one vertical slot oriented substantially from the at least one well to the other of the wells, and introducing a hydrofracturing fluid at least into the at least one well to produce a hydraulic fracture in direction from the at least one well to the other well.

Abstract: A system for increasing the productivity of oil, gas and hydrogeological wells has means for cutting slots only in a near well zone so as to perform a partial unloading of the well and to remove a part of support stresses, and means for cyclically treating well with a formation-treating substance so as to remove a remaining part of the support stresses, with controlling a density of a formation and correcting the cyclical treatment in correspondence with the density of the formation.