METHOD FOR BOTTOMHOLE TREATMENT OF OIL PRODUCING WELLS AND DEVICE TO IMPLEMENT SUCH METHOD Russian patent published in 2008 - IPC E21B43/25 E21B43/18 

FIELD: petroleum industry.

SUBSTANCE: invention is referred to petroleum industry, methods and devices to increase well production rate by treating near-wellbore zone of reservoir in order to remove various deposits. Wells shall be identified with bottomhole damaged by solid depositis with maximum current rate 3...5 m³/day. Composition of deposits of the identified well bottomhole shall be determined. Well is shutdown and submersible pumping equipment is run out of hole. Thermal/gas/chemical generator placed in tubular package is run in hole on tubing string to the target interval. Thermal/gas/chemical generator is made of solid particles of hydraulic reactant capable of exoergic reaction with water. Particles of hydraulic reactant are placed in cylindrical capsules (at least in one). Capsules are leak proof and manufactured of decomposable material and installed in the container cavity. Capsules with hydraulic reactant particles are filled with liquid chemical reactionless with hydraulic reactant but dissolving bottomhole deposits. Container is provided with radial windows at the envelope and contains capsule opening system arranged in the bottom part of the container. Capsule opening system is made as a piston mounted under the bottom capsule and rod with top part connected to the piston and low part to liner via axial channel in the bottom section of the container. The rod length is equal to the container length, with liner length equal to the distance from target interval to well bottomhole. Tubing string is leak proof and filled with air and provided with controlled valve in the bottom part with inlets to tubing string cavity and wellbore. Generator is started up and operated by communication with produced water. Generator shall be placed in top part of the target interval. Overbalance during thermal/gas/chemical stimulation is created by increase in well fluid level by installing of air chamber below the level simultaneously with thermal/gas generator.Volume of air chamber shall constitute minimum 25% of well fluid volume. Maximum time between pump shutdown and air chamber installation below the fluid level is 2 days. Well fluid level after air chamber installation is 5...15% higher than the static fluid level. Generator is started and thermal/gas/chemical treatment with simultaneous overbalance of the formation is performed in order to stimulate the formation. Underbalance treatment and stimulation of the formation are performed by decreasing well fluid level by decompression of the air chamber. Well shall be flushed to remove by-products of formation treatment. Submersible pump is run in hole and commissioned.

EFFECT: higher geological efficiency of well treatment, processability and engineering safety of well intervention activities.

2 cl, 4 dwg