RU2795655C1 - Method for reconstruction of an inactive well - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention is related to construction of wells intended for oil production, and, in particular, to technologies for drilling and completing sidetracks from the main wellbore to enable oil production from several productive underground reservoir zones. A method for reconstructing a well is claimed, in which kickoff and drilling of the first sidetrack are performed; a liner with pipes of maximum diameter is lowered above the kickoff window, where the liner head, made in form of a branch pipe with a half-turn helical line and a keyway, is installed below the planned window of the second sidetrack; the position of the head of the liner relative to the apsidal plane is determined; the wedge with the orienting lug is lowered; the window of the second sidetrack is cut out and the second sidetrack is drilled; after lifting the drill string, the wedge with the orienting lug is removed; the liner assembly of the second track with longitudinally profiled pipes in the upper part, to the shoe of which a hollow wedge is attached to the shear screws, is lowered; by pumping a cement slurry with a separating plug, the profiled pipes are inflated to the size of the second sidetrack and the inner diameter of the production string; then the liner of the second sidetrack is disconnected from the drill string; and the passability of the first sidetrack is restored.

EFFECT: reconstruction of an inactive well with the possibility of joint and separate production from sidetracks and the exclusion of the penetration of bridging agent and filtrate into the lower wellbores.

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Description

The invention relates to the construction of wells intended for oil production, and, in particular, to technologies for drilling and completing lateral branches from the main wellbore to enable oil production from several productive underground reservoir zones.

A device for multilateral opening of productive formations by one well (RU2197593) is known, including a housing rigidly connected to a branch pipe equipped with a seat for a removable wedge and having a groove for a key, a removable wedge with an orienting latch, configured to control the direction of the deflecting plane of the removable wedge and having a key that interacts with the groove of the branch pipe, and a sub. The body is made in the form of a longitudinally corrugated pipe, plugged from the bottom side and installed on the other side with a sub that connects it to the branch pipe and is provided with a bushing made of an easily drillable material for connection with the process string. The seat of the branch pipe is made in the form of an inclined surface passing into a longitudinal groove for a key installed in the seat sleeve of the orienting latch, one of the surfaces of which corresponds to the seating inclined surface of the housing branch pipe, and the other is provided with a toothed surface interacting with the toothed surface of the support sleeve rigidly fixed to shaft of the orienting latch, wherein the seat sleeve is rotatable on the shaft of the latch and locked in gear connection with the support sleeve by means of a clamping sleeve having a threaded connection with the shaft of the orienting latch. The retrievable wedge is configured to control the installation depth in the well by means of a replaceable extension placed between the orienting latch and the retrievable wedge. EFFECT: invention provides drilling of one or more lateral azimuthally directed boreholes due to precise setting of the recoverable wedge.

A device is known for lowering, securing and cementing a liner in a lateral wellbore (RU2658154), containing a node for disconnecting the liner hanger from drill pipes using a grip with a left-hand thread, connected to an anchor-packer node. In the lower part of this unit, a fixation unit for a suspended cementing plug is installed. The assembly for separating the liner hanger from the drill pipes is equipped with a landing sleeve with a half-turn helical support end surface. The anchor-packer unit contains two profiled expandable pipes hermetically connected to each other. One of them is rubber-coated and connected to the fixation unit of the suspended cementing plug. Said assembly contains a plunger. It is fixed by shear elements and blocks the communication channels between the internal suspension cavity and the internal space of the profile pipes. A guide assembly is attached to the last node through the liner casing string and shoe using a shear screw. It contains a hollow wedge with a through central hole, equipped with a guide sleeve with a half-turn helical support end surface.

A known method of building a multilateral well (RU2650161), characterized in that the main wellbore is drilled from the surface of the earth to the formation, a lateral wellbore is drilled from the previously drilled main wellbore, after drilling is completed, a casing string is lowered into the lateral wellbore, equipped in the upper part with a node for forming multi-barrel "joint" is not lower than the third level of complexity according to the TAML classification. The sidetrack drilling is carried out from the previously cased production string and cemented main wellbore, opening the intervals of unstable deposits prone to shedding and landslides, and the underlying zone with non-caving rocks with the opening of the productive formation and subsequent carrying out of a complex of geophysical surveys. The casing is lowered into the sidetrack from the lower section and at least one upper section, and lowered section by section, while the lower section is equipped with a receiving adapter-disconnector for connection with the next section, and the upper section has a length determined based on the actual depth descent of the previous section and the actual interval of the “window” milled in the string, is made of the same or larger diameter and includes at least one casing pipe equipped in the lower part with a connection unit with the previous section located in the well, and the upper one is equipped in the upper part with either a receiving adapter-disconnector, or a node for connecting to the next section, or a node for forming a multi-barrel joint not lower than the third level of complexity according to the TAML classification. EFFECT: improved quality of construction of multilateral wells, minimization of the risks of rejection during the construction of multilateral wells, due to non-admission of the liner. Its disadvantages are that an additional wellbore is drilled from a previously drilled new well, as well as a sectional liner running, in the claimed invention, two sidetracks are drilled from an inactive well, and the liner is lowered into one section.

A known method for the construction and completion of multilateral wells (RU2753417, selected as a prototype), in which the main wellbore is drilled, a section for the liner is drilled, a running tool with an orientation device, a liner and an anchor-suspension is lowered, a liner with an anchor-suspension is installed in an open hole wells at a given depth, determine the actual position of the orientation profile of the anchor in the well, activate the anchor, release the tool and raise the running tool to the surface, read the instrument data and determine the actual position of the anchor in the well, after which the assembly is run cutters and a hollow whipstock with a pre-set orientation at the mouth, the hollow whipstock is joined in the anchor-suspension and the whipstock is fixed in the anchor-suspension, while the top of the anchor-suspension is made in the form of a figured orientation profile, and the whipstock is made with an orientation key, the cutters are released from the whipstock and a branch of the wellbore is drilled along the whipstock, after which the liner is lowered, which is made with the possibility of producing fluid in the whipstock location interval.

The disadvantages of this method is that a new well is drilled to implement the method, and well joints are made in an open hole, which leads to a lack of control over the development, and during the drilling process, the previously drilled well will become clogged.

The technical objective of the invention is to enable sidetracking and drilling of additional sidetracks in an inactive well. The technical result is the reconstruction of an inactive well with the possibility of simultaneous-separate production from sidetracks. Another technical result is that with simultaneous-separate production from sidetracks, the penetration of colmatant and filtrate into the lower wellbores is excluded.

The technical result is achieved in a well reconstruction method, in which sidetracking and drilling of the first sidetrack are performed; lower the liner with pipes of maximum diameter above the kickoff window; the head of the liner, made in the form of a branch pipe with a half-turn helical line and a keyway, is installed below the planned window of the second sidetrack; determine the position of the head of the shank relative to the apsidal plane; lower the wedge with the orienting latch; cut out the window of the second sidetrack, drill the second sidetrack; after lifting the drill string, remove the wedge with the orienting lock; lowering the layout of the shank of the second barrel with longitudinally profiled pipes in the upper part, to the shoe of which a hollow wedge is attached to the shear screws; by pumping a cement slurry with a separating plug, the profiled pipes are inflated to the size of the second sidetrack and the inner diameter of the production string; disconnecting the liner of the second sidetrack from the drill string; patency in the first sidetrack is restored. The position of the head of the shank relative to the apsidal plane is determined by the inclinometer if there is a zenith angle in the trunk of more than 3 °, and at smaller angles - by a gyroscopic inclinometer . The wedge spoon is oriented in the range of 340-350° or 10-20° relative to the apsidal plane. Restoration of patency of the first lateral wellbore is carried out by assembly with a conical reamer, two watermelon reamers, which, in a rotary way, restore patency into the first wellbore by cutting a hole in the profile pipes further through a hollow wedge into the first lateral wellbore.

The invention is illustrated by drawings:

fig. 1 – cutting of the window of the second sidetrack;

fig. 2 - orientation of the wedge spoon in 1 quarter;

fig. 3 - inflation of profiled pipes.

In the proposed method of well reconstruction, the first sidetrack 1 is drilled by any known method. For example, an assembly is assembled from a hydraulic or hydromechanical anchor, a wedge, a set of cutters connected to the wedge with shear screws, hydraulically connected to the anchor with a tube, an orientation sub, and lowered on a drilling tool to the required depth. The wedge 3 is oriented by the devices, by creating excess pressure it is fixed by the tension of the drill string, the screws are cut, after which a drop-shaped window 8 is cut in the production string 2.

Upon its completion, the liner (the first liner) is lowered, and below the kickoff interval, the liner has a standard layout 7, above, pipes 4 of the maximum allowable size are used, since, in this interval, during operation, it is possible to install packers separating the wellbore.

The head 9 of the liner is installed 3-4 meters below the planned window 5 of the second sidetrack 6 and is made in the form of a branch pipe with a half-turn helical line and a keyway 10. If there is an inclination angle of more than 3 ° in the production string 2, the position of the head 9 is determined by a standard inclinometer shank (keyway 10) relative to the apsidal plane 11, and at smaller angles with a gyroscopic inclinometer its azimuth. The choice of measurement method is determined by the fact that at small angles in any direction, drilling is carried out in a vertical plane, there is practically no apsidal plane 11, relative to which you can navigate.

Then the layout of the wedge 12 is lowered (the layout can be performed, for example, in accordance with the one shown in Fig. 5 according to patent RU2197593), and the spoon 13 of the wedge must be oriented in 1 or 4 quarters, mainly in the range of angle α 340-350° or 10-20 ° relative to the apsidal plane 11, i.e. up (Fig. 2), depending on the desired direction of drilling. This orientation allows gravity to direct non-orientable downhole devices into the first sidetrack 1.

The drilling trajectory in the required direction is corrected so that the orientation of the horizontal wellbore (sidetracks) of the well to the dominant fracture direction is made at an angle of 25° to 40° (the choice of angles is justified in more detail in RU2717847, Fig. 8 and Fig. 9). Such a spatial orientation of a horizontal (lateral) wellbore makes it possible to take into account the processes of dispersion of filtering phases in fractured zones, as well as the processes of formation of water-oil emulsions in the wellbore and, as a result, prevent the processes of emulsion blocking of filtration in the oil reservoir. To obtain this trajectory, by discrete turns of the deflector motor by 25-30°, as the length passes from the bit end to the motor skew, the design zenith angle is set and the azimuth is corrected to the required value.

The layout of the liner (second liner) of the second sidetrack 6 is assembled, to the shoe of which a hollow wedge 15 is attached to the shear screws, made of a pipe of the same diameter as the upper pipes of the previously lowered liner of the first sidetrack 1. The bottom of the hollow wedge 15 is made in the form of a screw wedge. half a turn by the line reciprocal to the head 9 of the liner of the first sidetrack 1, and the upper oblique cut during landing will be set in the direction of the second sidetrack (detailed in RU2658154, pos. 14, 15, fig. 1).

With ribs 14, the window 5 of the second sidetrack is cut and cleaned, the second sidetrack 6 is drilled. After drilling the second sidetrack 6 and lifting the drill string, the deflecting wedge 12 is removed.

When the liner is lowered, the hollow wedge 15 unequivocally sits on the head of the liner of the hollow wedge 15. When the calculated load is created, the screw 13 is sheared and the shank along the upper oblique cut of the hollow wedge 15 goes to the second sidetrack 6. The lower part of the liner is assembled according to standard technology: shoe; check valve; stop ring. In the upper part of the liner, six or eight-beam longitudinally profiled pipes are assembled, and the lower profiled pipe 16 is coated with elastomer 17 on the surface and is installed in the window 5, acting as a packer, the upper one plays the role of a liner hanger and is fixed inside the production string 2.

Inside the profile pipes there is a pipe string, at the end of which a hanging plug is fixed on shear screws. A piston is installed at the bottom of the pipe string, which seals the cavity of the profiled pipes. The piston contains a plunger fixed by shear elements blocking the communication between the inner part of the piston and the cavity of the profiled pipes. The head of the shank is a branch pipe rigidly connected to the upper profile pipe with a half-turn helical line and a keyway. After lowering such a liner to the design depth, the estimated volume of cement slurry with a separating plug is pumped (an example of a separating plug is shown, for example, in Fig. 2 RU2658154), punching is carried out with a displacement fluid (technical water) or drilling fluid. During the punching process, the separating plug sits on the hanging plug, as a result of blocking the flushing hole, pressure increases and the screws fixing the hanging plug are sheared. Further, the separating plug together with the hanging plug move together to the stops of the ring, blocking its through hole. At the same time, pressure begins to rise, which signals the end of cementation. By increasing the pressure in the pipe space to the pressure of the shear screws that fix the plunger, they are sheared. The plunger is released and moves in the internal cavity of the piston, thus opening a message in the cavity of the profiled pipes. There is a creation of excess pressure inside the profiled pipes, which leads to their swelling to a size corresponding to the size of the second sidetrack 6 and the inner diameter of the production casing 2. Thus, the device is fixed from displacement. Elastomer 17, applied to the profiled pipe 16, provides sealing of the joint, which improves the quality of fastening.

The annular space 18 is cemented. Further, the excess pressure is released and the liner is disconnected from the drill string by right rotation of the last relatively easy to drill sleeve with a left-hand thread. Together with the pipes and the nipple part of the left sub, the following are removed attached to them: a pipe string, a piston with a plunger and a lock nut. This design eliminates the penetration of bridging agent and filtrate into the lower wellbores during drilling and provides the possibility of simultaneous-separate production from different sidetracks.

To provide access to the first sidetrack 1, an assembly is lowered, including a conical reamer, two watermelon reamers, with which, under limited load under the action of gravity, a tie-in begins through a profiled pipe 16 with the opening of a hollow wedge 15. Watermelon reamers, ensuring the rigidity of the layout, do not allow it to go into the second lateral shaft 6, when passing into the first lateral shaft 1, it is calibrated. So, the patency in the first sidetrack 1 is restored, which makes it possible to produce simultaneously-separate production from both sidetracks. Non-orientable devices descending, descending into the well unequivocally fall into the first sidetrack 1, since the sidetracking of the second sidetrack 6 was made in 1 or 4 quarters, i.e. up. The helical support surface (the head of the liner of the second wellbore is made similar to the head 9 of the liner) allows you to orient the descending devices in the second sidetrack 6. There is no interference (uncontrolled oil production) between the sidetracks made in this way, since there is isolation, in particular, a packer installed in the upper parts of the first shank.

Claims (4)

1. The method of reconstruction of the well, in which: produce sidetracking and drilling of the first sidetrack; lower the liner with pipes of maximum diameter above the kickoff window; the head of the liner, made in the form of a branch pipe with a half-turn helical line and a keyway, is installed below the planned window of the second sidetrack; determine the position of the head of the shank relative to the apsidal plane; lower the wedge with the orienting latch; cut out the window of the second sidetrack, drill the second sidetrack; after lifting the drill string, remove the wedge with the orienting latch; lower the layout of the liner of the second barrel with longitudinally profiled pipes in the upper part, to the shoe which is attached to the hollow wedge; by pumping a cement slurry with a separating plug, the profiled pipes are inflated to the size of the second sidetrack and the inner diameter of the production string; disconnecting the second sidetrack liner from the drill string; restore patency in the first sidetrack. 2. The method according to claim 1, characterized in that the position of the head of the liner relative to the apsidal plane is determined by the inclinometer in the presence of a zenith angle in the trunk of more than 3°, at smaller angles - by a gyroscopic inclinometer. 3. The method according to claim 1, characterized in that the spoon of the wedge with the orienting latch is oriented in the range of 340-350° or 10-20° relative to the apsidal plane. 4. The method according to claim 1, characterized in that the restoration of the patency of the first sidetrack is carried out by a layout with a conical reamer, two watermelon reamers, which restore the patency into the first trunk by cutting a hole in the profile pipes, then through a hollow wedge into the first sidetrack.

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