METHOD FOR DETERMINING EFFICIENCY OF HYDRAULIC WELL FORMATION FRACTURING Russian patent published in 2018 - IPC E21B43/267 E21B47/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the development of oil deposits and can be used for hydraulic fracturing with different permeability of rocks. Method includes conducting pre- and post-frac-pack studies, fracturing, determining the efficiency of the fracturing on the basis of indications obtained from the studies. Monthly, within three months before the hydraulic fracturing and immediately before the hydraulic fracturing, researches are carried out in which the formation and bottom-hole pressures and flow rates are determined, while before the frac-pack, the production inflow profile of the well along the height of the formation is determined and the intervals of the formation with high permeability rocks with an inflow above the average one in the formation are detected. Then, into the well along the process string of pipes, the bottom of which is placed below the perforations of the production string, process liquid with an insulating material is pumped at a rate of 0.2 m³ at 1 m of the height of the formation, made in the form of balls with a density equal to the density of the process fluid, isolating the perforations of the production string opposite high permeability strata along the inner diameter of the well, without penetrating into the bottom-hole formation zone, while the perforations of the production tubing opposite the low permeability strata remain uninsulated, the diameter of the balls being 1.2 times the diameter of the perforations in the production string. In this case, after the hydraulic frac-pack in the production well, once it is put into operation and for the next three months, the formation and bottom-hole pressures, flow rate, their mean values before and after the fracturing are determined monthly, then multiplicity of the increase in depression and production rates is determined, the line of the frequency of depression to the frequency of production rate relative to the initial line of the frequency of depression and production rate is plotted, while the line located on the graph above the original line of the frequency of depression and production rate indicates effective hydraulic fracturing, and the line located on the graph below the original line of the frequency of depression and production rate indicates ineffective hydraulic fracturing.

EFFECT: technical result consists in the simplification of the technology for determining the efficiency of hydraulic fracturing; reduction in labor intensity and costs of studies; increase in the accuracy of studies on the effectiveness of hydraulic fracturing; improvement of evaluation of the efficiency of hydraulic fracturing in a formation with different permeability of rocks; increase in the production rate after the fracturing in the formation with different permeability of rocks.

1 cl, 3 dwg