WELL SEAM HYDRAULIC FRACTURING Russian patent published in 2014 - IPC E21B43/267 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises well walls perforation in seam interval to depth of at least stress concentration zone length from well shaft. Pipe string with packer is lowered to seat it above the rood of perforated productive seam. Gelated fracturing fluid is injected to under-packer zone. Seam fracturing pressure is created in said zone to get seam fracture. Said fracture is, then, cemented by injection of gelated fluid, a carrier with dynamic viscosity of 30-50 cp with proppant with stepwise increase in concentration to 600-800 kg/m³ t every portion. Process fluid is injected into seam, well is held for pressure release, packer is released and withdrawn with pipe string from the well. Gelated fluid with calcium carbide is injected along with said fluid with proppant in three-five cycles and equal portions via pipe string. Fluid with calcium carbide is injected in amount one portion larger than fluid with proppant. Last fluid portion is fluid for water-based proppant while calcium-car-de-based fluid is used for crude oil. After aforesaid injection, 15%-water solution of hydrochloric acid is injected via pipe string in volume of crude oil injected into the well and forced through into seam in one and the half volume of pipe string. Well is held for chemical reaction for one hour. Pressure is, then, released via union fitted at wellhead into pipe string discharge line. Packer is released with withdrawn with pipe string from the well.

EFFECT: higher efficiency of fracturing, accelerated well development of hydraulic fracturing.

9 ex