SU1782267A3 - Threaded plug for loaded drill pipe - Google Patents

Description

The invention relates to tools for round tripping operations with drill collars (drill collars). '

Known threaded plug for drill collars, containing a housing with an annular shoulder in the upper part and threads in the lower part.

Known threaded plug for drill collars, containing a housing with an annular shoulder in the upper part, a threaded stop and thread in the lower part, a support collar for the elevator in the form of a ring, freely mounted on the housing between the annular shoulder and the threaded stop. The mounting element is made in the form of windows in the housing. Above the locking thread there is a cylindrical thread for screwing the threaded stop. Point contact elements are fixed on the lower end of the support shoulder. The support shoulder is installed on the housing with the possibility of rotation, limited axial movement and interaction of the elements of point contact with the upper end of the threaded stop in its lowest position. The threaded stop is made with the possibility of positioning its outer surface _t at a distance from the longitudinal axis of the body,. less than the distance of the outer surface of the drill collar from its longitudinal axis. The upper part of the body is made with a smaller diameter. The threaded stop is secured with a threaded stop. Point contact elements have a spherical surface. 1 wp f-ly, 2 dwg

pa, made in the form of a ring, mounted freely on the body between the annular shoulder and the threaded stop.

The closest to the proposed one is a threaded plug for heavy-weight drill pipes, containing a body with an annular shoulder έ of the upper part, a threaded stop and a thread in the lower part, a support collar for an elevator, made in the form of a ring, installed freely on the body between the annular shoulder and a threaded stop, and mounting element.

about 1782267 AZ

This plug is complex in design and manufacture, especially the spring 6 and shaped cage 5. The technology of assembling the plug, which should provide a certain force on the upper end of the collar after screwing the plug, is complicated. In this case, the axial force prevents the final tightening of the threaded connection with the drill collar. The need to create an axial force requires increased physical efforts from the performers of the application at this moment. In addition, in conditions of negative ambient temperatures, the support collar often freezes to the body or annular collar. As a result, when screwing up the drill collar plug with drill collars, which are down the well, the plug is unscrewed. Therefore, the threaded plug can fall down and injure the personnel at the wellhead.

The aim of the invention is to simplify the design and increase the operational reliability in conditions of negative ambient temperatures.

This is achieved by the fact that in a threaded plug for heavy-weight drill pipes, containing a body with an annular shoulder in the upper part, a threaded stop and a thread in the lower part, a support collar for an elevator, made in the form of a ring, mounted freely on the body between the annular shoulder and a threaded stop , and the mounting element, the threaded stop is removable and installed on the body with the ability to change its position in height and fixation, the support shoulder for the elevator is made with point contact elements at the bottom end and is installed with the possibility of rotation, limited axial movement and interaction with point contact elements with the upper end of the threaded stop in the lowest position. In this case, the threaded stop is made with the possibility of positioning its outer surface at a distance from the longitudinal axis of the body less than the removal of the outer surface of the drill collar from its longitudinal axis. Point contact elements have a spherical surface.

The named features of the threaded plug simplify its design, increase its operational reliability in conditions of negative outside temperatures. This reduces the cost of drilling wells, improves working conditions and reduces the possibility of personnel injury.

Figure 1 shows a threaded plug for drill collars after screwing; Fig, 2 is the same, at the moment of picking up the support shoulder by the elevator.

The screw plug consists of a body 1 having a locking thread 2 and a threaded stop 3 at the lower end, a support collar 4 for the elevator and an annular collar 5 at the upper end.

The support collar 4 for the elevator is made in the form of a ring mounted freely on the body between the annular collar 5 and the threaded stop 3 (Fig. 1). Above the locking thread 2 on the body 1, a cylindrical thread 6 is made for screwing the threaded stop 3, which allows you to change its position in height. Since the threaded stop is removable, it can be replaced in case of wear (from contact with the drill collar). This also allows you to make the required thread tension 2 when screwing the threaded plug from the drill collar 7. The support collar 4 for the elevator is made with point contact elements 8 at the bottom end and is installed with the possibility of rotation on the body, limited axial movement and interaction of point contact elements 8 with the upper end threaded stop 3 in its lowest position (Figs. 1 and 2). The presence of the elements 8 of the point contact prevents the lower surface of the support shoulder 4 from contacting the upper end of the threaded stop 3. This prevents the support shoulder from freezing. Threaded stop 3 is made with the possibility of positioning its outer surface at a distance from the longitudinal axis of the housing 1, less than the distance from the outer surface of the drill collar 7 from its outer axis. Due to this, the elevator only comes into contact with the outer surface of the drill collar 7. As a result, when screwing and unscrewing the drill collar plugs 7 with each other, the friction moment is not transmitted to the parts of the screw plug. The point contact elements 8 have a spherical surface.

The upper part of the housing 1 is made with a smaller diameter and windows 9 are made in it, into which, when screwing-unscrewing the screw plug, a crowbar or a key of another shape is inserted. Thus, this part of the body 1 is a unit for connecting the threaded plug with the means for screwing or unscrewing its threads 2. To prevent the accidental movement of the threaded stop 3 along the thread 6 during the screwing and unscrewing of the plug 7 from the drill collar 7, a locking element is installed 10 in the form of a threaded stop.

The screw plug works as follows.

The screw plug is inserted into the collar part of the drill collar 7 and screwed along the thread 2. The final fastening is performed with a crowbar inserted into the windows 9 of the housing 1. When the drill collar 7 is lifted by the elevator, the axial load from the weight of the drill collar 7 is transmitted through the housing 1 and the annular collar 5 to the support collar 4. When screwing in the drill collar 7. hanging on the elevator, together with it, the body 1 rigidly connected by the thread 2 with the collar 5 and the threaded stop 3. At this time, the upper part of the support collar 4 contacts the lower end part of the annular collar 5 (see Fig. 2). But since the support shoulder 4 is installed with the possibility of free rotation around the housing 1, it does not rotate at this moment. The frictional moment arising in this case is much less than the frictional moment required when unscrewing the thread 2. Considering that the drill collar 7 is hanging on the thread 2, under the influence of its weight the moment of unscrewing the thread increases significantly. All this prevents the spontaneous unscrewing of the thread 2 when screwing the drill collar 7 with the lower plugs lowered into the well. After screwing the UBT7 plug, suspended on the elevator, with the UBT 7, lowered into the well, it is lowered into the well until its upper end lands on the wedges. The elevator is removed. After the elevator is released, the support shoulder 4 is lowered down to the stop of the elements 8 on the upper end of the threaded stop 3. At the same time, an axial clearance appears from above (see figure 1). The clearance at the bottom is provided by the presence of point contact elements 8.

When unscrewing the screw plug, proceed in the reverse order. Inserting a crowbar into windows 9, unfasten the thread 2, and then holding the body 1 with your hands, unscrew the screw plug from the drill collar 7.

When unscrewing the drill collar. 7. suspended on the elevator, with the help of a threaded plug, the forces arising in this case tend to fasten the thread 2. By increasing the operational reliability and simplifying the design of the threaded plug, the tripping and lifting operations with the drill collar are accelerated and the working conditions are facilitated.

Claims (2)

Claim 1. A threaded plug for heavy-weight drill pipes, comprising a body with an annular 'collar in the upper part, a threaded stop and a thread in the lower part, a support collar for an elevator, made. and a mounting element, characterized in that, in order to simplify the design and increase the operational reliability in conditions of negative ambient temperatures, the threaded stop is removable and mounted on the body on the thread with the possibility of changing its? position in height and fixation, the support shoulder for the elevator is made with elements of point contact at the bottom end and installed with "vb" the threaded stop in its lowest lower position, while the threaded stop is made with the possibility of positioning its outer surface at distances from the longitudinal axis of the body less than the distance from the outer surface of the drill collar from its longitudinal axis. 2. Stopper by. Item 1, distinguished by the fact that the elements of point contact have a spherical working surface. S £!