METHOD OF DEVELOPMENT OF SANDWICH-TYPE OIL POOL USING HYDRAULIC FRACTURING Russian patent published in 2015 - IPC E21B43/14 E21B43/26 

FIELD: mining.

SUBSTANCE: according to the method, the displacement agent is injected through injection wells. The formation fluids are taken through production wells, the hydraulic fracturing is performed with obtaining of effective fracture of hydraulic fracturing. From each well the pilot borehole is drilled. During this drilling the stage-by-stage opening by the pilot borehole from top to down of the sandwich-type oil pool is performed. Using geophysical methods the viscosity of reservoir liquid and the direction of the minimum tension in layer by azimuth are determined. Test injections are performed and the minimum tension value is determined. After drilling of the pilot borehole in the well depending on viscosity and direction of tension from the pilot borehole of well in each productive layer in various directions from below one side borehole is drilled for each one. Drilling of side boreholes in layers with viscosity up to 20 mPa s is performed in the direction, perpendicular to the direction of the minimum tension in the layer. The hydraulic fracturing is performed with creation in the layer of longitudinal cracks from the side borehole. Drilling of side boreholes in layers with the viscosity above 20 mPa s is performed in the direction, perpendicular to the direction of the minimum tension in the layer. In this case the hydraulic fracturing is performed with creation in the layer of transversal cracks from the side borehole. Before drilling of each side borehole in the pilot borehole of well below layer the drillable packer is installed. When performing hydraulic fracturing with creation of longitudinal cracks into the side borehole the process pipe string with a filter and a packer is lowered. The packer is sat at the input to the side borehole and in the side borehole the hydraulic fracturing is performed by injection of hydraulic fracturing liquid by the process pipe string through the filter under the pressure exceeding the minimum tension. After that the process pipe string with the filter is extracted from the well, and the packer is drilled in the pilot borehole. The side borehole is drilled in the following overlying layer. When performing hydraulic fracturing with creation of transversal cracks into the side borehole the process pipe string with the jet nozzle fitted from below is lowered. In the side borehole by injection of hydraulic fracturing liquid by the process pipe string through the hydromonitor nozzle the interval-by-interval hydraulic fracturing is performed under the pressure exceeding the minimum tension with movement of the process pipe string. After that the process pipe string with the jet nozzle is extracted from the well, and the packer is drilled in the pilot borehole.

EFFECT: increase of output of production wells due to high performance hydraulic fracturing of layer.

4 dwg