METHOD OF INCREASING PRODUCTIVITY OF DEVELOPMENT WELLS AND INJECTION CAPACITY OF INJECTION WELLS Russian patent published in 2017 - IPC E21B43/18 E21B43/26 E21B43/02 

FIELD: oil and gas industry.

SUBSTANCE: under this method zones of exfoliation are created around the borehole by reducing and building up bottomhole pressure. To do this, a preliminary evaluation of the bed claying by core data is done and the least productive wells are selected for exposure in the zones of the formation composed of small- and medium-grained sandstones with a small content of clay, of siltstones and limestones. The selection and lowering into the borehole of an assembly with a jet or centrifugal pump is performed. The assembly provides applying a deep depression on the formation followed by a transition to the design conditions of the well operation. To form a system of microcracks in the formation, the bottomhole pressure is reduced gradually to the minimum technologically possible value. The process of the initiation and development of secondary microcracking is monitored using passive seismic monitoring methods. After the formation of the microcrack system is completed, the depression on the formation is gradually reduced until the inflow from the formation is completely stopped. After stabilizing the wellhead pressure, the well is put into operation as a development or injection well. The operation is done by switching several modes with a gradual build-up of depression or repression on the formation. The optimal amount of depression or repression is determined and the design operation conditions are adjusted.

EFFECT: increased production rates of development wells and injection capacity of injection wells due to a geomechanical impact on reservoir properties of the formation in the bottomhole areas and due to a transition to the well operation without the well killing.

10 cl, 5 dwg