Shape liner for improving perforation depth effect of shale oil horizontal well

Abstract

The invention relates to the technical field of oil and gas field development, in particular to a shaped charge liner for improving the perforation depth effect of a shale oil horizontal well. The shaped charge liner comprises a shaped charge liner outer surface A and a shaped charge liner inner surface B which are coaxially arranged; the shaped charge liner outer surface A comprises an outer wall top taper angle A01, a first outer wall middle part, a second outer wall middle part and an outer wall bottom A04 which are arranged from top to bottom; the top taper angle A01 of the outer wall is of a spherical structure, the middle of the outer wall is of a conical arc structure, and the bottom A04 of the outer wall is of a cylindrical structure; the shaped charge liner inner surface B comprises an inner wall top B01 and an inner wall main body which are arranged from top to bottom; the inner wall body is composed of a third arc B02 and a fourth arc B03. According to the shaped charge liner for improving the perforation depth effect of the shale oil horizontal well, the inner wall and the outer wall both adopt the hyperbolic structure design, and the reasonable quality control point M of the shaped charge liner is determined, so that the metal armor breaking jet flow form is effectively improved, and the head speed of jet flow and the control over the jet flow speed gradient are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil perforation, and particularly relates to a liner for improving the penetration effect of horizontal well perforation in shale oil. Background Art

[0002] In recent years, with the large-scale fracturing development of low-permeability and tight oil and gas reservoirs, when conventional perforating charges are used for eccentric perforation, due to the inconsistent gaps between the gun sleeves at each phase, the aperture of the casing perforation and the penetration depth of the formation holes are uneven, which in turn leads to a large difference in the amount of fracturing fluid entering each perforation hole during the hydraulic sand fracturing stimulation, seriously affecting the fracturing stimulation effect and the uniform utilization degree of the reservoir.

[0003] Although the existing equal-aperture perforating charges can solve the problem of hole consistency, due to the design concept of nearly equal wall thickness for the liner, the depth of the perforation channel is nearly 25% lower than that of the conventional perforating charge. At the same time, when the conventional perforating charge perforates, due to the impact and extrusion of the jet, a compaction zone is formed around the perforation channel, seriously reducing the conductivity of the channel, thereby affecting the productivity of the oil well. Summary of the Invention

[0004] (I) Technical Problems to be Solved The present invention provides a liner for improving the penetration effect of horizontal well perforation in shale oil, so as to solve the technical problems in the prior art that the penetration depth of the perforation channel is insufficient and there is a compaction zone around the perforation channel after perforation with equal-aperture perforating charges, resulting in a reduction in the conductivity of the channel, and further affecting the fracturing stimulation construction and the productivity of oil and gas wells.

[0005] (II) Technical Solutions To solve the above problems, the present invention provides a liner for improving the penetration effect of horizontal well perforation in shale oil, including: An outer surface A of the liner and an inner surface B of the liner arranged coaxially; The outer surface A of the liner includes a top wall cone angle A01, a first middle outer wall, a second middle outer wall, and a bottom wall A04 arranged from top to bottom; The top wall cone angle A01 is a spherical structure, the first middle outer wall and the second middle outer wall are conical arc structures, and the bottom wall A04 is a cylindrical structure; The first middle outer wall and the second middle outer wall are respectively composed of an arc A02 and an arc A03; The inner surface B of the liner includes a top wall B01 and an inner wall arranged from top to bottom; The top wall B01 is an ellipsoidal structure, the length of the major axis radius a of the ellipse is 5 - 10 mm, and the length of the minor axis radius b is half of the major axis a; The inner wall is composed of a first arc B02 and a second arc B03, and the first arc B02 and the second arc B03 are conical arc structures; The ratio of the height H1 at the middle of the first outer wall to the height H2 at the middle of the second outer wall is 1:1 to 1:3. Among them, the intersection point M of the middle part A02 of the first outer wall and the middle part A03 of the second outer wall is the reasonable control point for the mass of the liner.

[0006] Preferably, the radius SR1 of the conical angle A01 at the top of the outer wall is 6 - 13 mm.

[0007] Preferably, the arc length radius R1 of the middle part A02 of the first outer wall is 600 - 900 mm, the arc length radius R2 of the middle part A03 of the second outer wall is 400 - 800 mm, and R1 > R2.

[0008] Preferably, the intersection point of the first arc B02 and the second arc B03 of the inner wall is at the same horizontal position as the intersection point of the middle part A02 of the first outer wall and the middle part A03 of the second outer wall.

[0009] Preferably, the arc length radius R3 of the second arc B02 of the inner wall is 300 - 700 mm, the arc length radius R4 of the second arc B03 of the inner wall is 200 - 400 mm, and R3 > R4.

[0010] Preferably, the maximum diameter D1 at the bottom of the outer wall of the liner is 24 - 48 mm, and the height H4 is 1 - 2 mm.

[0011] Preferably, the maximum diameter D2 at the bottom of the inner wall of the liner is 22.5 - 46.5 mm.

[0012] Preferably, the liner is filled with metal powder. The formula of the metal powder adopts a reaction system of metallic zinc and nickel, where zinc powder is 15 - 30%, nickel powder is 10 - 30%, niobium powder is 5 - 10%, tungsten powder is 40 - 60%, and additive is 1 - 2%.

[0013] Preferably, the additive adopts polytetrafluoroethylene.

[0014] Preferably, the preparation method of the metal powder includes: First, pour zinc powder, nickel powder, and niobium powder into a ball mill in proportion at one time for uniform powder mixing for 120 min to form prefabricated powder, and then continue to pour tungsten powder and additive into the ball mill according to the mass ratio to fully mix with the prefabricated powder for 60 min, so as to prepare the equal metal powder.

[0015] (III) Beneficial effects The present invention provides a liner for improving the perforation penetration effect of horizontal wells in shale oil. Both the inner and outer walls adopt a hyperbolic structure design combined with the determination of the reasonable control point M for the mass of the liner, thereby optimizing the reasonable distribution of the mass of the liner, effectively improving the metal jet - penetration morphology, and being beneficial to enhancing the head velocity of the jet and controlling the jet velocity gradient. Brief Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the liner for improving the perforation penetration effect of horizontal wells in shale oil in the embodiment of the present invention; Figure 2 It is a schematic diagram of the liner parameters for improving the perforation penetration effect of horizontal wells in shale oil in the embodiment of the present invention; Figure 3 It is a partial schematic diagram of the apex angle of the liner for improving the perforation penetration effect of horizontal wells in shale oil in the embodiment of the present invention.

[0017] Wherein: A - Outer surface of the liner, B - Inner surface of the liner, A01 - Apex angle of the outer wall at the top, A02 - First arc, A03 - Second arc, A04 - Bottom of the outer wall, B - Inner surface of the liner, B01 - Apex angle of the inner wall, B02 - Third radian, B03 - Fourth radian, A04 - Bottom of the outer wall, SR1 - Radius of the apex of the outer wall, R1 - Radius of the first arc, R2 - Radius of the second arc, R3 - Radius of the third arc, R4 - Radius of the fourth arc, D1 - Maximum diameter of the outer wall of the liner, D2 - Maximum diameter of the inner wall of the liner, a - Semi-major axis radius, b - Semi-minor axis radius. Embodiment

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Example

[0019] This embodiment provides a liner for improving the perforation penetration effect of horizontal wells in shale oil, as Figures 1 - 3 shown, including a coaxially arranged outer surface A of the liner and an inner surface B of the liner.

[0020] The outer surface A of the liner includes an apex angle A01 of the outer wall arranged from top to bottom, a first middle part of the outer wall and a second middle part of the outer wall, and a bottom A04 of the outer wall. The apex angle A01 of the outer wall is a spherical structure, the first middle part of the outer wall and the second middle part of the outer wall are conical arc structures, and the bottom A04 of the outer wall is a cylindrical structure; the first middle part of the outer wall and the second middle part of the outer wall are respectively composed of a first arc A02 and a second arc A03.

[0021] The inner surface B of the liner includes an apex B01 of the inner wall and a main body of the inner wall arranged from top to bottom.

[0022] The top B01 of the inner wall is an elliptical spherical structure. The length of the major axis radius a of the ellipse is 5 - 10 mm, and the length of the minor axis radius b is half of the major axis a. The main body of the inner wall is composed of a third arc B02 and a fourth arc B03. The third arc B02 and the fourth arc B03 are conical circular arc structures.

[0023] As a specific solution of this embodiment, the maximum diameter D1 at the bottom of the outer wall of the liner is 38 mm, the overall height H of the liner is 40 mm, the radius SR1 of the top angle A01 of the outer wall is 9 mm, the radius of the middle arc A02 of the first outer wall is 880.24 mm, the corresponding height H1 of the liner is 13.5 mm, the radius of the middle arc A03 of the second outer wall is 720.66 mm, and the corresponding height H2 of the liner is 24 mm. The height H3 at the bottom of the outer wall of the liner is 1.55 mm.

[0024] The maximum diameter D2 at the bottom of the inner wall of the liner is 33.5 mm. The inner wall top angle B01 is an elliptical sphere with a major axis a of 7 mm and a minor axis b of 3.5 mm. The radius of the third arc B02 in the main body of the inner wall is 550.36 mm, and the radius of the fourth arc B03 in the main body of the inner wall is 250.36 mm.

[0025] The liner is filled with metal powder. The formula of the metal powder is 30% zinc powder, 15% nickel powder, 5% niobium powder, 50% tungsten powder and 1% additive. The additive in this embodiment uses polytetrafluoroethylene, which can react with metals, release heat, and also act as a binder.

[0026] In the metal powder formula of the present invention, zinc and nickel have relatively high densities and can release a large amount of heat under high-temperature conditions, enabling the water vapor in the pores to evaporate rapidly, thereby generating a large amount of gas in the pores and achieving the effect of pore cleaning, taking into account both the penetration depth of the pores and the pore cleaning effect.

[0027] The niobium powder in the metal powder formula has a relatively low density but can also release a large amount of heat under high-temperature conditions, and it has a good pore-expanding effect on the casing aperture.

[0028] The tungsten powder in the metal powder formula has the highest density and hardness, and it mainly undertakes the perforation function.

[0029] The preparation method of the metal powder is described below: First, pour zinc powder, nickel powder, and niobium powder into a ball mill in proportion and mix them evenly for 120 minutes to form a prefabricated powder. Then, continue to pour tungsten powder and the additive into the ball mill according to the mass ratio and mix them fully with the prefabricated powder for 60 minutes to prepare the metal powder.

[0030] The 89-type perforating charge manufactured with the liner designed by the present invention is loaded into an 89-type perforating gun (hole density 16 holes / m, phase 60°). When arranging the guns, eccentric perforation is adopted. It penetrates an API standard concrete target, and its average perforation depth reaches more than 1000 mm. The average aperture size on the casing is more than 10 mm, and the aperture stability is more than 95%. At the same time, a single-shot perforating charge is used for the simulated reservoir perforation test and the fluidity test, and the flow efficiency is increased by 30% compared with that of the conventional perforating charge. Example

[0031] This example provides a liner for improving the perforation depth effect of horizontal wells in shale oil, as Figures 1 - 3 shown, including a liner outer surface A and a liner inner surface B arranged coaxially. The liner outer surface A includes an outer wall top cone angle A01, a first outer wall middle part, a second outer wall middle part, and an outer wall bottom A04 arranged from top to bottom. The outer wall top cone angle A01 is a spherical structure, the first outer wall middle part and the second outer wall middle part are conical arc structures, and the outer wall bottom A04 is a cylindrical structure; the first outer wall middle part and the second outer wall middle part are respectively composed of a first arc A02 and a second arc A03.

[0032] The liner inner surface B includes an inner wall top B01 and an inner wall main body arranged from top to bottom.

[0033] The inner wall top B01 is an elliptical spherical structure, the length of the major axis a of the ellipse is 5 - 10 mm, and the length of the minor axis b is half of the major axis a; The inner wall main body is composed of a third arc B02 and a fourth arc B03, and the third arc B02 and the fourth arc B03 are conical arc structures.

[0034] As another specific solution of this example, the maximum diameter D1 of the outer wall bottom of the liner is 46 mm, the overall height H of the liner is 52.4 mm, the radius SR1 of the outer wall top vertex A01 is 12 mm, the radius of the outer wall middle arc A02 is 980.33 mm, the corresponding liner height H1 is 33.8 mm, the radius of the outer wall middle arc A03 is 749.65 mm, the corresponding liner height H2 is 65.9 mm, and the coverage H3 of the outer wall bottom of the liner is 1.75 mm.

[0035] The maximum diameter D2 of the inner wall bottom of the liner is 42.5 mm, the inner wall vertex B01 is an elliptical spherical shape with a major axis a of 9 mm and a minor axis b of 4.5 mm; the radius of the third arc B02 of the inner wall main body is 650.36 mm, and the radius of the fourth arc B03 is 350.36 mm.

[0036] The metal powder formula is 25% zinc powder, 13% nickel powder, 7% niobium powder, 55% tungsten powder, and 1% additive.

[0037] The preparation method of metal powder is described below: First, zinc powder, nickel powder, and niobium powder are poured into a ball mill at one time according to the ratio, and after 120 minutes of uniform powder mixing, a prefabricated powder is formed; Then, tungsten powder and additives are continuously poured into the ball mill according to the mass ratio and fully mixed with the prefabricated powder for 60 minutes to prepare the metal powder for the liner.

[0038] The 114-type perforating charge manufactured by using the liner designed by the present invention is loaded into a 114-type perforating gun (hole density: 16 holes / m, phase: 60°). When arranging the guns, eccentric perforation is used to penetrate the API standard concrete target. Its average perforation depth reaches more than 1200 mm, the average hole diameter on the casing is more than 12 mm, and the hole diameter stability is more than 97%. At the same time, a single perforating charge is used to conduct a simulated reservoir perforation test and a fluidity test, and the flow efficiency is increased by 40% compared with that of the conventional perforating charge.

[0039] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the patent protection scope of the present invention shall be defined by the claims.

Claims

1. A liner for improving the perforation penetration effect of horizontal wells in shale oil, characterized in that, Comprising: The outer surface A and the inner surface B of the liner, which are coaxially arranged; The outer surface A of the liner includes an outer wall top cone angle A01, a first middle part of the outer wall, a second middle part of the outer wall, and an outer wall bottom A04, which are arranged from top to bottom; The outer wall top cone angle A01 is a spherical structure, the first middle part of the outer wall and the second middle part of the outer wall are conical arc structures, and the outer wall bottom A04 is a cylindrical structure; The first middle part of the outer wall and the second middle part of the outer wall are respectively composed of a first arc A02 and a second arc A03; The inner surface B of the liner includes an inner wall top B01 and an inner wall main body, which are arranged from top to bottom; The inner wall top B01 is an ellipsoidal structure, the length of the major axis radius a of the ellipse is 5 - 10 mm, and the length of the minor axis radius b is half of the major axis radius a; The inner wall main body is composed of a third arc B02 and a fourth arc B03, and the first arc B02 and the second arc B03 are conical arc structures; The ratio of the height H1 of the first middle part of the outer wall to the height H2 of the second middle part of the outer wall is 1:1 to 1:

3. Among them, the intersection point M of the first middle part A02 of the outer wall and the second middle part A03 of the outer wall is the reasonable quality control point of the liner.

2. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, characterized in that, Comprising: The radius SR1 of the outer wall top cone angle A01 is 6 - 13 mm.

3. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, characterized in that, Comprising: The arc length radius R1 of the first middle part A02 of the outer wall is 600 - 900 mm, the arc length radius R2 of the second middle part A03 of the outer wall is 400 - 800 mm, and R1 > R2.

4. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, characterized in that, Comprising: The intersection point of the third arc B02 and the fourth arc B03 of the inner wall main body is at the same horizontal position as the intersection point of the first middle part A02 of the outer wall and the second middle part A03 of the outer wall.

5. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 4, characterized in that, Comprising: The arc length radius R3 of the third arc B02 of the inner wall main body is 300 - 700 mm, the arc length radius R4 of the fourth arc B03 is 200 - 400 mm, and R3 > R4.

6. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, characterized in that, Comprising: The maximum diameter D1 of the bottom of the outer wall of the liner is 24 - 48 mm, and the height H3 of the outer wall of the liner is 1 - 2 mm.

7. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, wherein Comprising: The maximum diameter D2 of the bottom of the inner wall of the liner is 22.5 - 46.5 mm.

8. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 1, characterized in that, Comprising: The liner is filled with metal powder, and the formula of the metal powder adopts a reaction system of metallic zinc and nickel, in which zinc powder is 15 - 30%, nickel powder is 10 - 30%, niobium powder is 5 - 10%, tungsten powder is 40 - 60%, and additive is 1 - 2%.

9. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 8, characterized in that, Comprising: The additive adopts polytetrafluoroethylene.

10. The liner for improving the perforation penetration effect of horizontal wells in shale oil as described in claim 9, characterized in that, Comprising: The preparation method of the metal powder includes: First, pour zinc powder, nickel powder, and niobium powder into a ball mill in proportion at one time for uniform powder mixing for 120 min to form prefabricated powder, and then continue to pour tungsten powder and additive into the ball mill according to the mass ratio to fully mix with the prefabricated powder for 60 min, so as to prepare the equal metal powder.

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