Method and apparatus for seismic stimulation of oil-bearing production formations

A method for producing the shock waves in borehole of a well filled or partially filled by a liquid for stimulation of production horizons of fluid bearing formations, comprising the steps of:

• a) positioning a device connected to a bottom of a tubing string extending downwardly into the borehole of the well filled or partially filled by the liquid and comprising:
• i) a linear permanent magnet motor connected to the bottom of the tubing string at the upper end and said linear permanent magnet motor is connected to the upper cylinder at the lower end;
• ii) a mover of linear permanent magnet motor connected to the upper plunger, movably arranged within said upper cylinder;
• iii) a lower cylinder connected to said upper cylinder via a compression chamber and said upper cylinder has a smaller internal diameter than an internal diameter of said lower cylinder;
• iv) a lower plunger connected to said upper plunger by means of at least one sucker rod and said upper and lower plungers movably arranged within said upper and lower cylinders, correspondingly, for compressing the liquid contained within said compression chamber and discharging the liquid into the borehole when said lower plunger exits out of said lower cylinder on the upstroke of said mover of linear permanent magnet motor thereby generating a shock wave;
• b) providing a required force N of said linear permanent magnet motor for said mover determined by the following expression:
• N
• ≥
• [
• π
• 4
• ⁢
• (
• D
• 1
• 2
• -
• D
• 2
• 2
• )
• ⁢
• A
• sw
• +
• g
• ⁡
• (
• M
• 1
• +
• M
• 2
• )
• ⁢
• (
• 1
• +
• k
• f
• )
• ]
• ,
• where D1 is the outside diameter of the lower plunger, D2 is the outside diameter of the upper plunger, Asw is the required amplitude of the generated shock wave, M1 is a mass of the lower and upper plungers, M2 is the mass of sucker rods, kf is a friction coefficient between plungers and corresponding cylinders, g is a gravity of acceleration.

An apparatus for producing shock waves in a borehole of a well filled or partially filled by a liquid for stimulation of production horizons of fluid bearing formations, comprising:

• a) a tubing string extending downwardly into the borehole of the well filled or partially filled by the liquid;
• b) a linear permanent magnet motor being connected and adjacent to a bottom of the tubing string at an upper end and an upper cylinder at a lower end, said linear permanent magnet motor having a mover connected with an upper plunger movably arranged within said upper cylinder
• c) a lower cylinder connected via a compression chamber to said upper cylinder having a smaller internal diameter than said lower cylinder
• d) a lower plunger movably arranged within said lower cylinder, said upper and lower plungers being connected to each other by means of at least one rod for compressing a liquid contained within said compression chamber and discharging the liquid into the borehole of the well when said lower plunger exits out of said lower cylinder on the upstroke of the pumping unit thereby generating a shock wave;
• and
• e. a production casing, wherein said linear permanent magnet motor is arranged within said production casing.