METHOD OF DEVELOPMENT OF GRAVEL ENVELOPE IN WELL Russian patent published in 2010 - IPC E21B43/04 

FIELD: oil and gas industry.

SUBSTANCE: method of development of gravel envelope in the well involves opening of productive formation with perforated casing string, wash of gravel to the space of casing string in perforation interval and to the space of cavities after the casing string with hydraulic sealing of bottom-hole formation zone (BFZ). In order to eliminate the disturbance of compact structure of sand in BFZ with formation of the cavity around the well bore owing to edging of formation sand from the well bore with further formation of compacted structure in BFZ, first, high-viscosity liquid - crosslinked gel is pumped under pressure to the formation. Then to the formed cavity and to the well bore there wound under pressure is gravel filling from high-permeability inwash fraction serving as sand filter for productive formation during operation of the well, which is made from polymer-coated material with density exceeding the density of formation sand at least by 3.5 times. At that, there simultaneously met is the condition as per the composition of gravel filter depending on particle size distribution of formation sand in compliance with Saucier criterion, according to which the median diametre of fraction particles of the filtering screen shall be more than that of formation sand by 5-6 times.

EFFECT: reducing the costs for inwash of the envelope and time for lowering-and-lifting operations.

3 cl, 1 dwg