APPLICATION OF VISCOUS GEL SOLUTIONS AND WATER SHUTOFF TECHNIQUES FOR LAYERS DURING WELL CONSTRUCTION

Most of the oil fields are at the decline stage of development. This stage of development is characterized by a decrease in the oil production level, an increase in the water cut of the extracted fluids (up to 90%). Reducing the water cut of the produced products is facilitated by water shutoff measures. Based on the analysis of the causes of growth of water cut in wells, the most common causes of high water cut in production wells include water filtration through fractured systems and highly permeable reservoir intervals, behind-the-casing crossflows and the formation of a water cut cone. Rational control over the water cut in the produced products increases the economic efficiency of the field development and reduces the costs of treatment and utilization of extracted water. There are different approaches for solving the problem of water shutoff: creating screens and barriers using various chemical compositions, using technical means and technological methods. These technologies are classified according to the nature of the impact of the injected water-insulating mass on the permeability of the oil-saturated part of the reservoir, opened by perforation. Taking this into account, water shutoff technologies are divided into selective and non-selective ones. The use of rigid gels is one of the methods of water shutoff in the near-well area. Gels can be injected selectively into the formation using coiled tubing (CT) and a packer. In case of absence of interlayer crossflows, an injection of a rigid gel into a watered-out formation can prevent unwanted water from penetration into the well.