RU90125U1 - DEVICE FOR SWABING WELLS WITH A LOW STATIC LEVEL - Google Patents

Abstract

A device for swabbing wells with a low static level, containing a cross-shaped mandrel, an emphasis, a swab cuff, a restrictive seat, characterized in that it is additionally equipped with a valve for crimping the tubing and a catcher of the valve body, the upper part of the body of the catcher and mandrel having the same shape and diameter.

Description

The utility model relates to the oil and gas industry and can be used in underground well repairs and in well development by swabbing.

Well swabbing is used to induce fluid flow into the well from reservoirs. The essence of the method consists in periodically taking products from the well using a mobile unit with a set of swab equipment based on the AzINMASH-32 elevator to a collection tank or stationary oil collection system by lifting it through a tubing string or tubing, depending on the operating conditions of the well. (V.M. Valovsky, K.V. Valovsky. Technique and technology for swabbing wells. Moscow. OJSC "VNIIOENG". 2003. p.15-16,).

A device for swabbing a well is known, mounted on a previously tubulated and equipped with a swab limiter (in the form of a restrictive sleeve) NKT-2.5 column (V.M. Valovsky, K.V. Valovsky. Technique and technology for swabbing wells. Moscow. OJSC "VNIIOENG" ". 2003. p.97-99). At the same time, a lubricator is installed at the wellhead to prevent air from entering the well and the accidental ejection of downhole equipment when the well develops during the swab process. Swab equipment descends into the well on a traction rope.

The cuff swab contains a central cross-shaped rod - mandrel, on which a swab cuff made of elastic material is mounted. A metric thread is threaded at the bottom of the mandrel, onto which a restrictive saddle is screwed.

Closest to the claimed technical solution is a device for swabbing wells, described in RD 39-0147585-220-01 "Technology for oil production from low-production and unequipped wells", developed by the TatNIPIneft Institute of OAO Tatneft. (2001, p. 7). The device is mounted on the basis of AzINMASH-37, and contains a mandrel, an emphasis, a swab cuff, a restriction seat, and a suction valve seat or restriction sleeve is installed as a swab limiter at the lower end of the tubing string.

In the process of swabbing wells through the saddle of the suction valve, downhole fluid flows from the tubing into the annulus. If a well operates a reservoir with optimal reservoir pressure, then the effect of overflows on lowering the level of wellbore fluid in the tubing is considered insignificant, and swabbing gives a positive result. And for wells with a low static fluid level in the tubing, the resulting overflows create an unfavorable situation, since a fluid level of at least 70-100 meters is necessary to open the swab cuff. Otherwise, the idling (descent-ascent) of the swab occurs, which also contributes to the premature wear of the cuffs.

Both devices for swabbing wells have the following disadvantage. During the up-and-down swab, overflow of well fluid from the tubing into the annulus and vice versa occurs, as a result of which when swabbing wells with a low static level, well-known devices for swabbing wells do not provide a sufficient height of the fluid column in the tubing.

The objective of the utility model is to provide the required level of fluid in the well by eliminating the flow of well fluid from the tubing into the annulus of the production string and vice versa.

The technical result is achieved by the proposed device for swabbing wells, containing a cross-shaped mandrel, an emphasis, a swab cuff, a restriction seat, a valve for crimping the tubing and a catcher of a valve body for crimping the tubing.

When swabbing wells with a low static level, the amount of fluid extracted by the swab decreases with each full (up-down) swab stroke. This occurs for the following reasons:

- slow recovery of the static fluid level in the well due to low reservoir pressure;

- due to overflow of well fluid from the tubing into the annulus when the swab moves down.

The problem is solved in that on the lower end of the tubing instead of the seat of the suction valve, a valve is installed for crimping the tubing string, manufactured by LLC “SEARCH” (Industrial catalog of manufactured products LLC “SEARCH”, http://firma_poisk.narod.ru). The valve contains two main nodes: a seat and a locking element. The valve shut-off element consists of a gripper, a centralizer, a shut-off body body that receives axial load, a sealing element, a pressure relief unit.

New in the proposed installation is that the crimping valve installed at the end of the tubing allows you to maintain the required fluid level in the tubing string for swabbing.

A device for swabbing wells with a low static level consists of a cross-shaped mandrel 1 (Fig. 1), a stop 2 (Fig. 1 and Fig. 3), a swab cuff 3 (Fig. 1), a restrictive seat 4 (Fig. 2), a valve 5 (FIG. 2) for crimping the tubing 6 (FIG. 2) with a centralizer 7 and a gripper 8 and a catcher of a locking member (FIG. 3) of valve 5 (FIG. 2) for crimping the tubing 6 (FIG. 2).

The proposed device operates as follows.

On the lower pipe string string 6 (figure 2) by means of a threaded connection, a restrictive seat 4 (figure 2) is installed from the valve 5 (figure 2) for crimping the tubing 6 (figure 2) and the tubing string 6 (figure 2) is lowered into the well. From the wellhead in the tubing 6 (FIG. 2), valve 5 (FIG. 2) with a centralizer 7 and a gripper 8 is dropped, which, under the action of gravity, is lowered down and, with the help of a centralizer-parachute 7, the saddle 4 fits tightly into the restrictive saddle (FIG. 2) valve 5 (figure 2), sealing the space inside the tubing 6 (figure 2). Then produce the process of swabbing the well.

When the swab moves down the tubing string 6 (figure 2) under the action of friction against the pipe wall, the swab cuff 3 (figure 1) moves along the cross-shaped mandrel 1 (figure 1) to the upper position until it stops 2 (figure 1), opening the passage for fluid through the channels along the cruciform mandrel and ensuring the swab is submerged under the fluid level. When the swab is raised, the cuff 3 (Fig. 1) under the action of the weight of the liquid column above the swab moves down the mandrel 1 (Fig. 1) to the lower stop 4 (Fig. 1) and is pressed against the inner surface of the tubing 6 (Fig. 2), providing tight contact.

At the same time, when the swab basket moves upward, valve 5 (FIG. 2) for crimping the tubing 6 (FIG. 2) with a centralizer 7 and gripper 8 is lifted and passes through the tubing 6 (FIG. 2) due to the pressure rarefaction in the subsurface space a portion of liquid, and when the swab basket reaches the upper point, valve 5 (FIG. 2) is lowered into the restrictive seat 4 (FIG. 2) mounted on the tubing 6 (FIG. 2), while maintaining a static level in the well. And so on, until the well is fully developed, i.e. ensuring a steady flow of fluid into the well. After the production of the well development, the mandrel 1 (Fig. 1) is lifted with a cuff 3 (Fig. 1), and a catcher (Fig. 3) is installed on the traction rope to catch the crimping valve 5 (Fig. 2) for capturing 8 (Fig. 2) ) In this case, the upper part of the catcher body (Fig. 3) and the mandrel 1 (Fig. 1) are made in the form of a stop 2 (Fig. 1) and (Fig. 3) having the same shape and diameter. This allows the traction rope of the swab unit to be used both for swabbing and for catching the shut-off element of the crimping valve, without making additional changes to the attachment of these devices to the traction rope of the swab unit.

The proposed device does not require additional material costs for manufacturing, since all the components and components are available in teams of underground repair of wells. The device has been successfully tested and is used for swabbing wells with a low static level at NGDU Elkhovneft OAO Tatneft.

Claims (1)

A device for swabbing wells with a low static level, containing a cross-shaped mandrel, an emphasis, a swab cuff, a restrictive seat, characterized in that it is additionally equipped with a valve for crimping the tubing and a catcher of the valve body, the upper part of the body of the catcher and mandrel having the same shape and diameter.