RU2225505C1 - Method for well-adjacent layer area treatment - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: method includes connecting a well-washing apparatus to hole space and tubing string. Treatment periods include forming of depressive pressure overfall between well-adjacent layer area and well hollow by means of prior pumping of fluid into the well and creation of periodic pressure impulses in well-adjacent layer area in form of dumped stationary wave moving in hole space of well. Treatment periods are interchanged with well washing by means of said respective apparatus. EFFECT: combined well hollow and well-adjacent layer area cleaning. 2 dwg

Description

The alleged invention relates to mining and can be used to develop and restore the production rate of production wells, which decreased as a result of the mudding of the borehole zone of the formation by asphalt-resin-paraffin formations and solids.

A known method of processing the borehole zone of the formation and a device for its implementation (Agliullin M.N., Kurpanov A.S., Rakhmatullin R.Kh., Abdullin M.M. Patent No. 2123591, class E 21 B 43/25), when which produce simultaneous physical and pulsed depression and repression to stabilize the current values of hydraulic conductivity.

However, for the implementation of the method requires the use of a string of tubing, descent of equipment and cable using a winch, etc.

There is a method of processing the bottom-hole zone of the formation (Orlov G.A., Khusainov V.M., Musabirov M.Kh., Pestrikov V.I. Patent No. 2169821, class E 21 B 43/25), when using which they are lowered into the well implosion device, pump the processing compound, push it into the reservoir, carry out cleaning by creating multiple implosion exposure.

However, the implementation of the method requires the use of tubing string, packer, implosion device, processing composition, etc.

A known method of cleaning a well from deposits during its operation (Veliev F.G., Kurbanov R.A.-I., Aliev E.N., Patent No. 1700207, class E 21 B 37/00), in which they periodically create negative pressure waves, for which the valves on the flow line are closed and kept in the closed state, then opened.

However, the maximum pressure change from water hammer when opening the flow line is 1.5 MPa for a fraction of a second, which is not enough for the formation of a powerful wave, in addition, it is necessary to use a tubing string and a pump to ensure its power supply.

There is a method of development and cleaning of the bottomhole zone of wells by pulse drainage (Nosov P.I., Senochkin P.D., Nurislamov N.B. et al. Patent No. 2159326, class E 21 V 43/25), taken as a prototype, in wherein the formation of a depression of the pressure differential between the borehole zone of the formation and the well cavity is done by pre-pumping fluid into the well, creating periodic pressure pulses in the borehole zone of the formation in the form of a damped standing wave moving along the well cavity, and bleeding off the pressure when the fluid moves along kvazhine of the well bore formation zone to the surface at a sharp opening borehole cavity.

However, after the outflow of the borehole fluid, particles of contaminants remain in the borehole cavity, of which large ones settle on the bottom of the well, and small ones remain in suspension and, when the cleaning or pumping operation continues, they again settle on the walls of the pore channels.

The objective of the invention is a comprehensive cleaning of the cavity of the well and a section of the reservoir adjacent to the bottomhole zone.

The problem is solved by the fact that using a method of processing the borehole zone of the formation containing treatment periods, including the formation of a depressive pressure drop between the borehole zone of the formation and the cavity of the well, by pre-pumping fluid into the well, creating periodic pressure pulses in the borehole zone of the formation in the form of a decaying standing wave, moving along the well, and bleeding pressure when moving the fluid through the well from the near-wellbore zone of the formation to the surface, creating a damped standing the first wave moving along the well, and pressure relief when moving the fluid through the well from the borehole zone of the formation to the day surface is carried out in the cavity of the annular space of the well, treatment periods, including the formation of a depressive pressure drop between the borehole zone of the formation and the cavity of the well, the creation of periodic pressure pulses in the near-wellbore zone of the formation in the form of a damped standing wave moving along the cavity of the annulus of the well, and pressure relief during movement and fluid in the annular cavity is alternated with flushing the well using a flushing unit connected to the annulus of the well and to the tubing.

This method allows you to display the adsorption deposits of the pore channels of the borehole zone of the formation in the cavity of the well, then remove them using a standard installation for flushing wells.

An example of a device for implementing the proposed method is illustrated in the drawing (diagrams a and b), in which: 1 - pipe annulus; 2 - tubing; 3 - downhole zone of the reservoir. The arrows in the diagram a of the drawing show the direction of motion of the standing shock wave, the arrows in the diagram b show the direction of fluid movement during flushing the well.

The method is implemented as follows. Installation for washing wells is connected to the annular space of the well through the pipe 1 to the tubing 2.

A fluid is pumped into the well using the pump of the installation through the pipe of the annulus 1 or the tubing 2 and create a pressure that is safe for the integrity of the tubing, casing and cement stone. Under the influence of excessive pressure, the fluid penetrates into the borehole zone of the reservoir.

For the formation of a standing shock wave, the cavity of the annulus is opened and, when a sufficient flow rate of the fluid is reached, the flow is blocked. A pressure wave is formed, which moves along the well cavity from the wellhead to the bottom and back, creating impacts, including in the near-wellbore zone of the formation. Repression and depression impulses make it possible to disrupt adsorption deposits on the walls of pore channels.

The formation of a standing shock wave is also possible by shock application of pressure to the surface of the well fluid at the wellhead.

After passing the oscillations of the standing shock wave, the well fluid is poured out for depressive removal of contaminants from the near-well zone of the formation. The contaminants are actively carried out into the well cavity and move to the wellhead with the fluid flow, and light particles of contaminants float to the surface, heavy particles settle in the sump of the well, small and colloidal ones disperse and remain in suspension in the well fluid. In addition to contaminants from the near-wellbore zone, there are contaminants in the well cavity that are torn off by the shock wave from the walls of the casing and tubing.

Periodically, between the operations of cleaning the pore channels of the near-wellbore zone of the formation, the washing of the well is carried out. The process is repeated until the required degree of purification of the borehole zone and well cavity is achieved.

The installation for washing wells has a set of equipment sufficient for the operation of forming a depression of the differential pressure between the borehole zone of the formation and the cavity of the well, to create periodic pressure pulses in the borehole zone of the formation in the form of a decaying standing wave, to relieve pressure during a sharp opening of the well cavity, and to create a pressure shock on the surface of the well fluid. No additional equipment required.

The fluid may contain chemicals for more efficient cleaning. The method can be applied in conjunction with other types of bottom-hole treatment: acidic, thermal, vibrational, acoustic, etc.

Claims (1)

A method for processing a borehole zone of a formation comprising treatment periods including the formation of a depressurized pressure differential between the borehole zone of a formation and a well cavity by pre-pumping fluid into the well, creating periodic pressure pulses in the borehole zone of the formation in the form of a damped standing wave traveling through the well, and relieving pressure at moving fluid through the well from the near-wellbore zone of the formation to the surface, characterized in that the creation of a damped standing wave downstream of the well, and pressure relief when the fluid moves through the well from the borehole formation zone to the day surface, treatment periods are carried out in the annulus of the wellbore, including the formation of a depressurized pressure differential between the borehole formation zone and the well cavity, the generation of periodic pressure pulses in the borehole formation zone in in the form of a damped standing wave moving along the cavity of the annulus of the well, and pressure relief when the fluid moves along the polo The annular space of the well is alternated with the flushing of the well using a well flushing unit connected to the annular space of the well and to the tubing.

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