CN112593903A

CN112593903A - Fixed-firing-angle inner blind hole perforating gun

Info

Publication number: CN112593903A
Application number: CN202011469832.XA
Authority: CN
Inventors: 贺建磊; 徐志国; 石前; 乔亚波; 汤占军
Original assignee: Daqing Oilfield Perforation Equipment Co ltd; Daqing Petroleum Administration Bureau; China National Petroleum Corp
Current assignee: Daqing Oilfield Perforation Equipment Co ltd; Daqing Petroleum Administration Bureau; China National Petroleum Corp
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-04-02

Abstract

The invention discloses an inner blind hole fixed firing angle perforating gun, which comprises a gun body (2), wherein an inner blind hole (0) is arranged on the gun body (2), and the perforating gun is characterized in that: the inner blind hole surface (8) of the inner blind hole (0) is vertical to the jet flow axis (7) of the perforating bullet (4); the problem of when current fixed firing angle perforation along with the increase of perforating bullet inclination, perforation length, jet velocity and jet energy all will descend by a wide margin is solved.

Description

Fixed-firing-angle inner blind hole perforating gun

Technical Field

The invention relates to a special part of a shaped charge perforator in the field of petroleum logging, in particular to a perforating gun.

Background

The perforating gun is a main component of the shaped perforator and is a carrier of components such as a perforating bullet, a bullet rack and the like, and shaped jet formed by explosion of the perforating bullet can enter a stratum only by firstly perforating a gun body, so the gun body of the perforating gun is used as a first layer target plate of jet and has very important influence on the shaped jet formed by the perforating bullet.

The fixed-angle perforation technology is a perforation technology which is carried out on a vertical well inclined stratum or an inclined well horizontal stratum. In the conventional perforating gun, the shot of the perforating charge is vertical to the gun, so the perforation only shoots at the projection direction of the maximum principal stress on the horizontal plane, and the middle part of the perforation is different from the projection direction of the maximum principal stress on the horizontal plane by an angle, thereby not only ensuring that the perforation yield-increasing effect is not obvious, but also causing the phenomena of mistakenly shooting bottom water and shooting a thin layer.

Therefore, the perforator with the fixed perforating angle and the fixed direction is researched, the perforator can solve the perforating problem of the conventional perforator, and the development effect of the oil-gas well is improved. However, the fixed-angle perforator only adjusts the angle of the perforating charge, the shot of the perforating charge is not necessarily perpendicular to the gun, but the angle of the perforating charge is adjusted according to the field situation, and as shown in fig. 1, the angle of the perforating charge is adjusted to be inclined by 10 degrees, 20 degrees and 40 degrees.

However, the shaped jet formed by the perforating charge with the inclination angle obliquely impacts the inner wall of the perforating gun, and researches show that the phenomenon has great influence on the penetration depth of the perforating charge, and the jet speed and the jet energy are reduced. The specific reason is as shown in fig. 1, as can be seen by comparing the perforating bullet with the angle of inclination of 10 °, 20 ° and 40 ° with the perforating bullet perpendicular to the perforating gun, the perforating length of the perforating bullet in the vertical case is L, and the perforating lengths of the perforating bullet in the angle of inclination of 10 °, 20 ° and 40 ° are L1, L2 and L3 respectively. Test verification shows that L1= (85% -90%) L, L2= (75% -85%) L, and L3= (40% -50%) L; that is, as the angle of inclination of the charge increases, the perforation length will decrease substantially, so that the jet velocity and jet energy also decrease substantially.

Disclosure of Invention

In view of the above, the invention provides an inner blind hole fixed-firing-angle perforating gun, which solves the problem that the perforation length, the jet speed and the jet energy are all greatly reduced along with the increase of the inclination angle of a perforating charge during the existing fixed-firing-angle perforation.

In order to achieve the purpose of the invention, the perforating gun with the fixed firing angle of the inner blind hole comprises a gun body, wherein the gun body is provided with the inner blind hole, and the perforating gun is characterized in that:

and the inner blind hole surface of the inner blind hole is vertical to the jet flow axis of the perforating bullet.

Further, a bullet rack is arranged in the gun body;

the perforating charges are arranged on the charge frame.

Furthermore, the bottom end of the gun body is connected with the gun tail, and the upper end of the gun body is connected with the gun head;

the bullet rack is fixed between the gun tail and the gun head.

The invention has the following beneficial effects:

the inner blind hole surface adopted by the inner blind hole fixed-firing-angle perforating gun is an inclined surface, the inclined inner blind hole surface is ensured to be vertical to the jet flow axis of the perforating bullet as far as possible, and the inclined inner blind hole surface is used as a first layer target plate of the perforating bullet energy-gathered jet flow, so that high-speed and collimated energy-gathered jet flow can be formed, the explosive height of perforating is improved, the attenuation of the jet flow speed and energy is reduced, and the perforating length of the perforating bullet is improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a blind internal hole fixed-firing-angle perforating gun of the background art of the present invention;

FIG. 2 is a schematic structural view of a blind inside hole fixed angle perforating gun of an embodiment of the present invention;

FIG. 3 is a schematic illustration of a partial configuration of a blind inside hole fixed angle perforating gun in accordance with an embodiment of the present invention;

FIG. 4 is a schematic illustration of the blind via configuration of the present invention with an inclined 10 angle charge of an embodiment of the present invention;

FIG. 5 is a schematic illustration of the blind via configuration of the present invention with an inclined 20 angle charge of an embodiment of the present invention;

FIG. 6 is a schematic illustration of the blind via configuration of the present invention with an angled 40 angle charge of an embodiment of the present invention;

in the figure, 1-gun tail, 2-gun body, 3-detonating cord, 4-perforating bullet, 5-bullet frame, 6-gun head, 7-jet axis, 8-inner blind hole surface with inclination angle and 9-the thinnest area of the gun body.

Detailed Description

The present invention will be described below based on examples, but it should be noted that the present invention is not limited to these examples. In the following detailed description of the present invention, certain specific details are set forth. However, the present invention may be fully understood by those skilled in the art for those parts not described in detail.

Furthermore, those skilled in the art will appreciate that the drawings are provided solely for the purposes of illustrating the invention, features and advantages thereof, and are not necessarily drawn to scale.

Also, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, the meaning of "includes but is not limited to".

In fig. 2, the perforating gun with the fixed firing angle for the inner blind hole of the embodiment comprises a gun tail 1, a gun body 2, a bullet rack 5 and a gun head 6, a perforating bullet 4 is arranged in the bullet rack 5 at a certain inclination angle, and a detonating cord 3 is arranged in the perforating bullet 4. The gun body 2 is provided with an inner blind hole 0, an included angle is formed between the inner blind hole surface 8 of the inner blind hole 0 and the axis of the gun body 2, and the included angle is consistent with the inclination angle. The inner blind hole 0 structure can be realized by an inner blind hole sidetracking technology.

As shown in connection with fig. 3: the area through which the jet axis 7 of the charge 4 passes is the inner blind face 8 which is angled, the inner blind face 8 being as perpendicular as possible to the jet axis 7 of the charge 4.

After the perforating bullet 4 is detonated by the detonating cord 3, the drug cover is crushed on the jet flow axis 7 of the perforating bullet 4 to form high-speed and collimated energy-gathered jet flow, the energy-gathered jet flow firstly impacts the inner blind hole surface 8 with an inclination angle, the attenuation of the jet flow speed and energy can be reduced, the perforating length of the perforating bullet is improved, and the energy-gathered jet flow penetrates through the gun body 2 to realize the perforation of a sleeve and a stratum.

The case of the angle of inclination of the perforating charge, specifically 10 °, 20 ° and 40 ° is described in this embodiment.

FIG. 4 is a schematic illustration of the blind via configuration of the present invention with an inclined 10 angle charge of an embodiment of the present invention; under the condition, because the inclination angle is smaller, the inner blind hole surface 8 can be perpendicular to the jet flow axis 7 of the perforating bullet 4, and when the safety of the thinnest region 9 of the gun body is ensured to be similar to that of a conventional inner blind hole perforating gun, the length H1 from the center of the gun to the inner blind hole surface 8 is not greatly different from the conventional inner blind hole length H, the influence on energy-gathered jet flow is small, and the original design of the perforating bullet is met.

FIG. 5 is a schematic illustration of the blind via configuration of the present invention with an inclined 20 angle charge of an embodiment of the present invention; due to the fact that the inclination angle is increased, when the safety of the thinnest area 9 of the gun body is similar to that of a conventional inner blind hole perforating gun, the diameter of the inner blind hole surface 8 does not completely enter the gun body 2, or the inner blind hole surface 8 can be milled by a drill bit with a small diameter under the condition that jet flow of the perforating bullet 4 is not affected. The length H2 from the gun center to the blind inner hole surface 8 in this case is not much different from the conventional blind inner hole length H and does not greatly affect the jet flow.

FIG. 6 is a schematic illustration of the blind via configuration of the present invention with an angled 40 angle charge of an embodiment of the present invention; because inclination is very big under this kind of circumstances, when guaranteeing that the thinnest region 9 security of body of a gun is similar with interior blind hole perforating gun in the conventionality, can make interior blind hole face 8's area very little, influence the fluidic normal tension of perforating bullet 4, consequently to the condition at this kind of big inclination, need guarantee in under the area of blind hole face 8 does not influence fluidic condition, acquire alpha's value, mill out this interior blind hole face 8. Maximizing the performance of the charge 4 is achieved. In this case, the length H2 from the gun center to the blind bore face 8 is greater than the conventional blind bore length H, resulting in an increased explosive height of the perforating charge and improved performance for deep-penetration.

The above-mentioned embodiments are merely embodiments for expressing the invention, and the description is specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, various changes, substitutions of equivalents, improvements and the like can be made without departing from the spirit of the invention, and these are all within the scope of the invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides an interior blind hole fixed firing angle perforating gun, includes body of a gun (2), blind hole (0) in setting up on body of a gun (2), its characterized in that:

the inner blind hole surface (8) of the inner blind hole (0) is vertical to the jet flow axis (7) of the perforating bullet (4).

2. The blind inside hole fixed firing angle perforating gun as claimed in claim 1, wherein:

a bullet rack (5) is arranged in the gun body (2);

the perforating charges (4) are arranged on the charge carrier (5).

3. The blind inside hole fixed firing angle perforating gun as claimed in claim 1, wherein:

the bottom end of the gun body (2) is connected with the gun tail (1), and the upper end of the gun body is connected with the gun head (6);

the bullet rack (5) is fixed between the gun tail (1) and the gun head (6).