DEVELOPMENT METHOD OF LOW-PERMEABILITY OIL FORMATION SECTION Russian patent published in 2019 - IPC E21B43/267 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used in development of a section of a low-permeability oil reservoir using vertical cracks of multistage hydraulic fracturing of the formation (MHFF) in order to maintain formation pressure (MFS). Method of developing a section of a low-permeability oil formation includes recovering an oil-saturated formation with an average absolute permeability of not more than 2 mD, drilling in a given formation of a horizontal well, cementing in the annular hole of the annular space between the casing and the header, secondary opening of the header, multistage hydraulic fracturing of the formation – MHFF, application of packers for separation of horizontal shafts into sections, extraction of products from the horizontal well. At that, selecting the section of oil-saturated formation, above or below which there is water-saturated formation, wherein between said oil-saturated and water-saturated formations the total thickness of the interlayer of the non-collector is not more than 30 m. After the initial MHFF in the oil-saturated formation, the well is put into production and operated till the oil flow rate is reduced to 5–10 % of the initial oil flow rate obtained on the average for the first month of operation, followed by repeated MHFF in each second stage of the initial MHFF. At that height of cracks is made so that the cracks pass through the non-reservoir formation and involve a water-saturated formation. After the repeated MHRP, each new stage of MHFF is tested, when producing oil inflows, the well is mined for oil, stages of repeated MHFF are isolated by packers; the well is left for redistribution of pressure for a period of up to 2 months, after which it is put into production; besides, due to the fact that stages of repeated MHFF are isolated, extraction is performed only from stages of initial MHFF. At that, stages of repeated MHFF ensure maintenance of formation pressure from water-saturated formation.

EFFECT: increasing oil recovery of a section of a weakly permeable oil formation.

1 cl, 1 dwg