Perforating gun and machining method for gun body of perforating gun

Abstract

The invention relates to the field of oil-gas field development engineering, in particular to a perforating gun and a machining method for a gun body of the perforating gun. The problem that after a perforating gun enters a stratum, the shooting direction of perforating bullets cannot be ensured. The perforating gun comprises a gun body, a bullet rack and perforating bullets, and further comprisestwo directional rings, wherein a plurality of notches are formed in the bullet rack; the perforating bullets are mounted on the notches in a one-to-one correspondence manner; each three notches are arranged into a group and are spirally distributed on a metal tube; the perforating bullets mounted in the middle of each group of notches are perpendicular to the axis of the corresponding metal tube;the perforating bullets mounted at two ends of each group of notches are mounted obliquely; it can be ensured that a surface formed by three points, which are shot by each group of perforating bullets, on a sleeve is perpendicular to the sleeve; the gun body is a metal tube; outer blind holes which are in one-to-one correspondence to the perforating bullets are formed in the outer surface of thegun body; the directional rings are eccentric rings; the two directional rings are separately and fixedly arranged at two ends of the gun body in a sleeving manner; and the orientations of the two directional rings are the same.

Description

technical field [0001] The invention relates to the field of oil and gas field development engineering, in particular to a perforating gun and a processing method for the gun body. Background technique [0002] Because horizontal wells can increase the exposed area of ​​oil and gas layers and increase oil and gas production, they have been widely used in major oil and gas fields in recent years. As of 2013, the number of horizontal wells excluding Sinopec, CNOOC and Yanchang Petroleum, only CNPC horizontal wells The number of wells is close to 6,000. Horizontal wells are suitable for thin oil layers and fractured oil reservoirs, especially for shale oil and shale gas that have developed rapidly in recent years. [0003] Drilling horizontal wells is technically difficult, and perforating before production is even more difficult. For the perforation of ordinary vertical wells, it is enough to put the perforating gun into the perforation section by using tubing. The perforati...

AI Technical Summary

Problems solved by technology

[0004] In each horizontal perforation section, the perforation direction of the perforating bullet should be towards the thicker direction of the reservoir, because the orientation of the reservoir corresponding to the wellbore is different, and the direction of perforating bullet injection is also different. The orientation of the oil layer in the perforation section can be determined according to the According to the well data, the shooting direction of the perforating bullet can be processed in advance in the factory. However, after the perforating gun is lowered into the formation, because the perforating gun rotates in the casing, it is impossible to guarantee that the perforating bullet will be injected into the oil reservoir to be shot. ; In addition, the cartridge holder holes in the traditional perforating gun adopt spiral distribution, and the direction of perforating bullet ejection is perpendicular to the axis of the perforating gun. The pressure must be higher than the fracture pressure of the rock formation to generate cracks in the rock formation. As a result, the wellhead pressure must be very high, and the high pressure operation is not only costly, but also poses a great safety hazard during the construction process. At the same time, the cracks produced by the explosive gas of gunpowder Due to formation pressure, there is a tendency to close, which will affect subsequent fracturing operations

[0005] The blind holes on the outside of the gun body of the perforating gun correspond to the holes of the bullet holder, and are also distributed in a spiral manner, and the relative position of each blind hole on the gun body is strictly controlled according to the logging data (the perforating bullets need to pass through the blind hole to enter the logging hole). The oil reservoir orientation calculated by the data), which requires precise positioning when processing the blind hole on the gun body, and the current processing method is difficult to accurately position the circular tube gun body, resulting in a very low yield. Serious waste of rough pipe

Images