METHOD FOR INVESTIGATION OF HEIGHT AND DIRECTION OF FORMATION FRACTURING Russian patent published in 2020 - IPC E21B49/00 E21B43/267 G01V1/40 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used for determination of azimuthal direction and crack height after hydraulic fracturing (HFT) in rocks with weakly cemented bottom-hole formation zone. Method involves drilling a well with opening of a productive formation and a sump, fastening a well casing string by cementing a borehole space from the wellhead to the bottomhole, productive formation perforation and acoustic cementometry, background measurement in the productive formation interval by cross-dipole acoustic logging, performing hydraulic fracturing of the formation – HFT by lowering the tubing string with the packer to obtain a fracture break and fixing its proppant, performing main measurement in the interval of the productive formation by cross-dipole acoustic logging, determination of fracture crack height and its direction along azimuth by results of background and main measurements. At that, between performance of background measurement in interval of productive formation by method of cross-dipole acoustic logging and performing HFT additionally performing density logging in the HFT interval and determining formation rock density in the HFT interval, then multi-stage HFT is performed with installation of lower end of pipe string at distance of 5 m above formation roof, wherein in the final stages of the HFT fastening fracture crack is carried out by pumping crosslinked gel resin-coated lightweight fraction 20/40 mesh proppant with density of 1,570 kg/m³ when the rock density less than 1,650 kg/m³, or weighted resin-coated fraction 16/30 mesh proppant with density of 1,800 kg/m³ when the rock density higher than 1,650 kg/m³, before pumping the resin-coated proppant is heated at the wellhead to temperature of 55–60 °C.

EFFECT: high reliability of results of investigation of height and direction of propagation of a fracture of the formation, high efficiency of the method, productivity of the well, folded from weakly cemented rocks, after putting it into operation.

3 cl, 3 dwg