METHOD FOR DEVELOPING BITUMINOUS ARGILLITE AND SANDSTONE FIELDS Russian patent published in 2019 - IPC E21B43/16 E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the field of the oil industry, namely to improving the efficiency of the development of bituminous mudstone and sandstone fields. Initially, a well is drilled, which opens the target object, and downhole equipment is installed to ensure the well production is raised and the solvent is injected at a pressure above the hydraulic fracturing pressure. Section of the well that opens the target object is cut off from the remaining intervals by the packers. Solvent capable of dissolving the target object's bitumen is cyclically injected into the target object through the well. At the beginning of the cycle, the solvent is fed to the well under pressure exceeding the hydraulic fracturing pressure. At the same time, hydraulic fractures are created in the target object in the perforation interval, providing a large contact area of the solvent with a large amount of bituminous rocks, and bitumens are extracted from them. Hydraulic fracturing is carried out without adding a proppant, thereby ensuring the closure of cracks, which makes it possible to expect no loss of solvent during the development process. After that, the well is left for process hold-up for a time t. Time t is determined in the laboratory, based on the core samples of the target object. After the process hold-up, the solvent is lifted with hydrocarbons dissolved in it onto the daylight surface, as well as other hydrocarbons that have become available for the development of this reservoir due to the increase in hydrodynamic bonds. For this, the borehole equipment, which previously provided injection of solvent into the object, is switched to the well production lifting mode. After the pressure in the well site perforation interval reaches its minimum level, the solvent injection-lifting cycle is repeated, repeating the steps described from the beginning of the cycle. Since fractures produced by hydraulic fracturing are completely closed during the production of bituminous mudstone, loss of solvent during the development process is minimal. At the same time, this well is used as an injection well when injecting solvent, and as a production well when extracting hydrocarbons.

EFFECT: technical result consists in increasing the oil recovery coefficient.

1 cl, 4 dwg