CENTRALIZER FOR CASING PIPE USED IN WELL DRILLED BY TRICONE DRILLING BIT Russian patent published in 2006 - IPC E21B17/10 

FIELD: oil and gas industry, particularly casing of wells having problem intervals.

SUBSTANCE: centralizer comprises hollow body formed as two rings connected one with another by convex centering ribs, which extend at an angle to outer body surface generator. Working surfaces of the ribs are defined by parts of tore surfaces created by rotating circles having r_c·cosα radii about straight lines intersecting well axis at (90°-α) angles. Distance L between circle centers and axes of circle rotation is selected from the following equation: L=(0.95-0.99)·R_b-r_c , where L is distance from centers of rotation of circles having radii equal to r_c·cosα, to circle rotation axes mm, r_c - tricone drilling bit cone radius, mm, R_b - drilling bit radius, mm, α is angle between centering rib and outer body surface generator, deg.

EFFECT: provision of ascending cement mortar flow turbulization, increased well casing quality and improved permeability of casing column and downhole equipment to be lowered through problem intervals of well, enhanced well flushing and cementing conditions.

2 cl, 2 dwg