Patent EP-2426311-A2 (EP)
Inventor: ABRAMOVA ANNA VLADIMIROVNA
IPC: E21B28/00
Filed: 2010-04-16
Abstract: The invention relates to area of oil production, specifically to oil recovery with use of energy of elastic vibrations and can be with high efficiency realized in course of works exceeding 2000 meters. 
     The method for oil recovery with use of energy of elastic vibrations including placements in a well on working depth of downhole apparatus (4), which is connected to aboveground power supply units (2 and 3) and contains ultrasonic transducer (14) that provides for the generation of high frequency elastic vibrations, exciting elastic vibrations of different frequencies and then repeatedly applying the elastic vibrations to the oil formation (pool), wherein both high and low frequency vibrations are applied to the pool, note that the low frequency vibrations are generated with electric-pulse device, which is connected to an aboveground power supply (3) and comprises the following electrically interconnected components: a charger (15), a unit (16) of energy storage capacitors (17), a discharge unit with electrodes (18, 19), and two switching means (21, 22), one of which (21) provides grouping of charging capacitors (17) in one single unit (16) and the second (22) carries out switching of energy storage capacitors (17) from one type of electrical connection to another while impact of elastic vibrations of high frequency is performed in low frequency ultrasonic range, mainly on frequency 18 - 44 kHz and is continued in constant and/or pulse regime with intensity in the range of 1 - 5 Wt/sm2, and impact of elastic vibrations of low frequency is performed with discharge frequency of 0.2 - 0.01 Hz and with energy of single discharge equal to 100 - 800 J, note that DC voltage is supplied from power supply (3) to charger (15) with magnitude in the range of 300 - 150 V before charging energy storage capacitors (17) they are grouped in one single unit (16), charging of the unit (16) of charging capacitors (17) is carried out mainly with parallel connection of capacitors and is continued mainly during 20 seconds up to required level of voltage magnitude, with maximum magnitude equal to 20 - 27 kV. and before discharging of unit (16) of energy storage capacitors (17) providing supply of output voltage on electrodes (18 and 19) of discharging unit, all charging capacitors (17) or part of them are switched into series electrical connection, together with this impact with elastic vibrations of low and high frequency is performed sequentially and/or simultaneously mainly in fixed position of downhole apparatus (4), continued with constant and/or varying electrical and acoustical characteristics of aboveground and/or in-well equipment and technological parameters of oil recovery process and mainly during permanent or periodical pulling out of oil from a well. 
     The device realizing a method according to claim 1 includes aboveground power supply units (2, 3) and downhole apparatus (4) provided with control unit (1), which by electrical cable (5) is connected to aboveground power supply units (2, 3), designed as empty cylindrical body (6) and separated by partitions 7, 8 and 9 into hermetical modules 10, 11, 12 and 13 and contains source of elastic vibrations of high frequency designed as ultrasonic transducer (14)  characterised in that  it additionally contains source of low frequency elastic vibrations, which developed e.g. on basis of electro-pulse device connected to aboveground power supply (3) and placed in downhole apparatus (4), note that electro-pulse device contains electrically interconnected charger (15) unit (16) of energy storage capacitors (17), discharging unit with electrodes (18 and 19) and two switching means (21 and 22), one of which (21) provides grouping of charging capacitors (17) in one single unit (16) and the second (22) carries out in the unit (16) of energy storage capacitors (17) switching of capacitors from parallel connection to the series one and vice versa from series connection to the parallel one, note that switching means (21 and 22) are designed mainly as one device, which is placed in one module with the unit (16) of energy storage capacitors (17) and modules (11 and 12) of downhole apparatus (4) which contain unit (16) of energy storage capacitors (17) and source of elastic vibrations of high frequency (14) are filled with electro-insulating material (24).