RU2206724C2 - Method of producing formation development - Google Patents

Abstract

FIELD: oil producing industry; applicable in tapping and development of oil producing formation on new and already operating wells for stimulation and renewal for operation of wells at late stage of development, and also for increase of injectivity of injection wells used for maintaining formation pressure. SUBSTANCE: method includes perforation of casing string of, as least, one well and cutting of channel in cement stone, withdrawal of product from producing well with subsequent cutting of channel in formation. Perforation is effected by introduction into casing string to preset depth of guide shoe secured in suspension of tubing, introduction of high-pressure flexible hose into guide shoe, installation on its end of hydraulic motor, flexible shaft and toothed milling cutter. Flexible shaft and milling cutter are hydraulic motor, flexible shaft and toothed milling cutter. Flexible shaft and milling cutter are rotated by hydraulic motor to form hole in casing string and channel in cement stone. Flexible hose with hydraulic motor, flexible shaft, and milling cutter are withdrawn from guide shoe. Introduced into hole of casing string and channel in cement-stone through guide shoe is erosion perforator with jet nozzle for formation of frontal cutting jets and thrust reactive jets. This provides for advance of perforator in frontal direction and withdrawal of washed rock into wellbore. If required, perforation is repeated in other direction and at other level. EFFECT: increased oil recovery from producing formation. 3 dwg, 3 ex

Description

 The invention relates to the oil industry and may find application in the opening of reservoirs of new wells, stimulation and resuscitation of wells at a late stage of development, as well as to increase the injectivity of injection wells used to maintain reservoir pressure.

 A known method of developing a productive formation, including drilling a well, injecting a working agent through injection wells, selecting products through production wells, drilling additional shafts from previously drilled producing wells and selecting products through drilled additional shafts (see, for example, RF patent 2091566, 27.09. 1997).

 The known method allows to increase oil production, however, it is time-consuming in terms of determining the flow rate of water on horizontal shafts, and a significant part of the oil is not extracted from the reservoir.

 The closest analogue of the invention is a method of developing a productive formation, which includes injecting a working formation through injection wells and taking oil through production wells (see, for example, RF patent 2153064, 07.20.2000).

 The known method does not provide the necessary oil recovery of the reservoir.

 The technical result of the invention is the creation of a method that allows to increase oil recovery.

 The necessary technical result is achieved by the fact that in the method of developing a productive formation, which includes injecting a working agent through injection wells and taking oil through production wells, according to the invention, additional casing is perforated by at least one well by introducing into the casing to a predetermined depth of the guide shoe fixed to the suspension of tubing with the subsequent introduction of a flexible high-pressure hose into it with a hydraulic motor installed at its end , with a flexible shaft and gear cutter, rotate the flexible shaft and gear cutter by means of a hydraulic motor for cutting a hole in the casing and a channel in cement stone, after which a flexible hose with a hydraulic motor, flexible shaft and gear cutter is removed from the guide shoe, then into the hole in the casing and a channel in a cement stone, a hydroperforator with a nozzle nozzle is inserted through the guide shoe to cut through the channel layer due to the formation of front cutting jets and thrust jet jets, which ensures advancement perforator in the front direction and stem scoured rock into the borehole, after which, if necessary, a perforation is repeated in a different direction or at a different level.

 When developing oil deposits, significant oil reserves remain in the reservoir due to imperfect methods of opening the reservoir or its operation.

 The claimed method is implemented as follows.

 In the process of developing a productive formation when used in the process of introducing drilled wells by known methods, in particular, bases on a cross by charges of a casing string and cement ring, undesirable destructive conditions for wells are created. The method of hydro sandblasting perforation is based on the use of kinetic energy and abrasive properties of a jet of liquid with sand flowing out at a high speed from the nozzle of a special perforator and directed to the wall of the well. In a short time, a stream of liquid with sand forms a hole in the casing and a channel in the cement stone. Liquid with sand is supplied to the nozzles of the perforator along the tubing string with pumps installed near the well. This method of opening the formation is used: in new wells, in wells that have left drilling, and in production wells in order to increase their productivity.

 However, the perforation of the casing and the cutting of the channel in the cement stone by known methods are insufficient for a more complete extraction of oil. The formation of channels in the reservoir (including horizontal) allows you to: reduce the cost of oil production, increase the rate of oil extraction, current and final oil recovery factors.

 The essence of the claimed method is illustrated by drawings, where in FIG. 1 shows a general diagram of a method; in FIG. 2 - unit device with a gear mill; in FIG. 3 - unit device with a nozzle nozzle. A guide shoe 7 (see FIGS. 1 and 2), screwed through an adapter 2 to the end of the suspension of the tubing, is lowered into a newly drilled or operated well for a design interval into the casing. To cut a side hole in the casing and cement stone, a flexible high-pressure hose 5 is lowered into the tubing, onto which a hydraulic motor 17, a flexible shaft 12 and a gear mill are fastened 10. The flexible hose is lowered and lifted from a trailer with a drum and depth gauge, and water is supplied carried out by a high pressure pump. The pressure at the outlet of the high pressure pump is at least 2000 atmospheres. After cutting holes in the column and channel in the cement stone, a flexible hose with a hydraulic motor, a flexible shaft and a mill is raised to the surface. At the end of the flexible hose, a nozzle nozzle 11 is inserted and lowered back into the well. The nozzle nozzle through the guide shoe enters the cut hole, and after turning on the high-pressure pump, it starts cutting through the horizontal channel 9 in the reservoir 15. Due to the presence of holes 13, the nozzle nozzle forms front cutting jets, and due to the presence of side holes 14, thrust jet jets which provides advancement in the frontal direction and at the same time removal of the washed rock into the wellbore. Removing excess working fluid is carried out through the hole 16 at the wellhead. Description of an example implementation of the method.

 Example 1 (prototype).

The productive layer of the Baydankinskoye field is opened with the following characteristics: porosity - 16%, average permeability - 0.646 μm ² , oil saturation - 60.1%, absolute mark of water-oil contact - 1100 m, average oil-saturated thickness - 3.5 m, initial reservoir pressure - 9.5 MPa, reservoir temperature 27 ^o С. Formation oil parameters: density - 940 kg / m ³ , viscosity - 67 MPa • s, saturation pressure - 1.8 MPa, gas content - 8 m ³ / g, sulfur content - 3 ,8%.

 Wells are drilled into the deposits, casing is perforated, the working agent is injected through injection wells, additional channels in the well are drilled at a given depth, production is taken through additionally cut channels (including horizontal channels).

 Example 2 (by the present method) is carried out analogously to example 1.

 In drilled wells, during the opening of the formation for perforation in the required interval of the reservoir, the guide shoe 7 is lowered into the casing 1.

 The guide shoe 7 has a channel inside at an angle of 90 degrees to give the desired direction to the cutting tool and nozzle nozzle, and is set so that it can be rotated inside the casing 1 to be installed in the desired position for cutting horizontal channels.

 The work of cutting holes and horizontal channels is carried out in two stages.

 At the first stage, a high-pressure flexible hose with a hydraulic motor, a flexible shaft and a gear mill fixed at the end is inserted into the well through the tubing and a guide shoe, a flexible shaft and a gear mill are rotated through the hydraulic motor and holes are cut in the casing and cement stone.

 In the second stage, at the end of the high-pressure flexible hose, the nozzle nozzle is lowered, which is inserted through the guide shoe into the cut hole and a channel 9 is cut through the productive formation 15, about 60 m long. Then, the guide shoe can be rotated 90 degrees beyond the upper end of the tubing suspension and repeat the process in a different direction, then you can cut other holes in the casing in four directions at the same level or in four directions at different levels.

 Flexible high-pressure hose with an internal diameter of 8-12 mm is made of elastomeric material and can withstand an internal fluid pressure of up to 2000 atm. A flexible high-pressure hose is wound around a rotating drum mounted on a freestanding platform. The high-pressure pump is also installed on an independent platform and has an independent drive. A container of water is brought separately to the place of work.

 The time for cutting a hole in the casing and the channel in the cement stone is 10-15 minutes, and the time for cutting the channel from the casing to a distance of 30 meters is up to 2 hours. After performing the required number of horizontal channels in the productive strata of the well, a high-pressure flexible hose with a tool is removed from the well and wound on a drum. A water tank, platforms with a pump and a drum, and auxiliary equipment are removed from the wellhead. The underground repair team performs the lifting of the tubing string with a shoe, washing the bottom of the well and developing the well according to the regulations.

 Example 3 (by the present method).

The Baidankinskoye oil field is being developed with the following characteristics: porosity - 16%, average permeability - 0.646 μm ² , oil saturation - 60.1%, absolute mark of water-oil contact - 1100 m, average oil-saturated thickness - 3.5 m, initial reservoir pressure - 8 , 9 MPa, reservoir temperature 25 ^o C.

Formation oil parameters: density - 960 kg / m ³ , viscosity - 67 MPa • s, saturation pressure - 1.8 MPa, gas content - 5 m ³ / g, sulfur content - 3.2%.

 Wells are placed in the deposits and they have been producing oil for at least 20 years before reaching a water cut of 70%. According to the method described in example 2, the channels are cut in the reservoir, and product is additionally selected through the cut channels in the reservoir.

 As a result of using the proposed method, the flow rate of wells increases up to 12 times.

Claims (1)

 A method of developing a productive formation, including pumping a working agent through injection wells and extracting oil through production wells, characterized in that they perform additional perforation of the casing of at least one well by introducing a guide shoe fixed to the suspension of the tubing into the casing at a predetermined depth with the subsequent introduction of a flexible high-pressure hose into it with a hydraulic motor mounted on its end, a flexible shaft and a gear mill, rotate the flexible shaft and gear threaded cutter by means of a hydraulic motor for cutting a hole in the casing and the channel in the cement stone, after which a flexible hose with a hydraulic motor, a flexible shaft and a gear mill is removed from the guide shoe, then a hydraulic hammer is introduced through the guide shoe into the hole in the casing and the channel in the cement stone nozzle-nozzle for cutting through the channel layer due to the formation of frontal cutting jets and thrust jet jets, which ensures the punch advancement in the frontal direction and removal of washed through ode in the wellbore, and then, if necessary, a perforation is repeated in a different direction or at a different level.

Images