RU2194856C2 - Device for depressurization of cavities of test downhole equipment assembly - Google Patents

Abstract

FIELD: equipment for fluid sampling from formation with the help of formation tester on pipes. SUBSTANCE: device hollow partition made in the form of bushing with clamp is installed movably in cavity of detachable sub. Partition external surface has grooves for control of device through open side hole made on sub. Plug installed in sub lower side channel serves for prevention of hollow partition from spontaneous displacement. Device is designed for depressurization of cavities and formation testing downhole equipment in its disassembly after completion of operation cycle. Device makes it possible to perform lowering of geophysical instruments through testing equipment in the course of formation testing and provides for safe performance of operations involved in depressurization of cavities of test downhole equipment assembly. EFFECT: extended functional potentialities of simplified design; higher reliability of device. 2 dwg

Description

 The invention relates to techniques for sampling fluid from a formation using formation testers on pipes (IPT), in particular, to devices for depressurizing cavities of production testing well equipment when disassembling it after the end of a work cycle. A device is known for depressurization of cavities of an assembly of test downhole equipment (SU 690173, class E 21 B 49/00, 08/30/1979), comprising: a sub with an axial channel (internal cavity), a plug, a housing, integral with the sub and placed across the axis sub, in the 2-stage blind axial channel of which is placed a hollow spool, mechanical seal.

 It is also known a device adopted as a prototype (SU, 1328504, class E 21 B 49/00, 08/07/1987), containing a hollow sub with side channels, a hollow partition rigidly connected by a sub, in the cavity of which a piston sealed by rings is placed, with the possibility of movement when the screw rotates, and the piston is closed with a plug with an axial bore.

 The principal disadvantage of the above devices is the inability to lower geophysical instruments during the formation testing through the test equipment, as they do not have a central channel structurally.

 In addition, in these devices, the exhaust channels cannot be made large enough, while the fluid coming from the formation may contain large solid particles that can clog small channels of the devices, which reduces the reliability and safety of depressurization or collection of fluid samples.

 The objective of the invention is to expand the functionality by launching geophysical instruments through test equipment during the formation testing, simplifying the design, as well as improving the reliability of depressurization of closed cavities by eliminating clogging of channels.

 The solution to this problem is achieved by the fact that in a device containing a hollow sub with side channels, a hollow partition and a plug installed in the sub, the sub is detachable, consists of two parts interconnected by threads, side channels are placed at the top of the hollow sub and are offset relative to each other in height and an open lateral hole is made, the hollow partition is made in the form of a hollow sleeve with a collar and is movably and coaxially located in the cavity of both parts of the sub two rows of o-rings are located on the surface of the upper part of the hollow partition, between which opposite the open side hole grooves are made to control the device, and outlet holes are made in the lower part of the hollow partition, the plug is installed in the lower side channel with the possibility of contact with the butt end of the hollow partition collar, preventing it spontaneous upward displacement, and sealing rings are placed in the cavity of the hollow sub to seal the hollow partition with the lower part of the hollow vodnika.

 The total area of the slit openings is equivalent to the area of the central channel of the septum, that is, in comparison with the prototype, the area of the outlet openings is increased 50-100 times.

Compared with well-known technical solutions, the proposed device has structural and technological advantages:
- allows you to run the geophysical instruments in the process of testing the formation through the test equipment, for which the partition is made in the form of a hollow sleeve, i.e. has a central through channel;
- eliminates the possibility of clogging with slurry of the exhaust channel, which increases the reliability and safety of depressurization of closed cavities;
- reliably isolates the closed cavity of the test equipment layout, which has increased pressure, from the borehole and external space.

 The invention is presented in the drawing, in which Fig. 1 shows a general view of the device in the transport position (slotted holes are closed), and Fig. 2 shows a layout of the test equipment using the device.

 The device contains a hollow sub, consisting of two parts: upper 1 and lower 2, connected by a thread and sealed by rings 3. In the upper part of the sub there are lateral channels A and B displaced in relation to each other in height. In the cavity of both parts of the sub, the hollow partition 4 is movably and coaxially installed, on the outer surface of which there are two rows of sealing rings 5 and 6 for sealing the upper (open) side channel, and grooves 7 are made between the sealing rings through which the device located opposite open upper side hole 8, made in the upper part of the sub 1. Below the sealing rings on the partition 4 made a shoulder 9, which does not allow the partition 4 to move down (emphasis on the end of the bottom of the sub 2) or up (emphasis on the plug 10 installed in the lower side channel B of the sub 1).

 A turn-key groove is made at the outer end of the plug 10, the length of the plug is chosen so that it contacts the end of the collar 4 with the second end. The plug 10 is designed to protect the thread and side channel B from contamination during the descent of the tool into the well, as well as to prevent from spontaneous displacement of the septum 4 up. Slotted outlet openings 11 are made in the lower part of the hollow partition 4, and sealing rings 12 are placed in the inner cavity of the sub 2 to seal the hollow partition with the lower sub.

 The device operates as follows.

 The device for depressurization 13 (Fig. 2) in the transport position (Fig. 1) is installed in the layout of the test equipment directly under the upper shut-off valve 14 and above the lower shut-off valve 15 (for example, a formation tester) on one or more pipes 16 (drill or pump -compressor). The principle of controlling the shut-off valve does not matter, but it is important that the upper shut-off valve 14 is closed earlier than the lower 15. When the specified depth is reached, part of the weight of the pipes is unloaded to the lower part of the assembly, while the packer 17 expands and seals the studied area from the rest of the well, shut-off valve 15 opens. The liquid or gas through the filter 18, the packer 17 from the test formation enters the pipe cavity 16, passes through the sealing device 13 and the upper shut-off valve 14 into the pipe 19. The control and regulation devices 20 fix the inflow curve. After a certain time, the shutoff valve 14 closes and from the moment of closing, the devices 20 register a curve for the restoration of reservoir pressure.

After the test, the IPT assembly together with the device is raised to the surface, while pressure remains in the closed cavity between the valve systems. For depressurization of a closed cavity, work is performed in the following sequence:
- the plug 10 is unscrewed and a fitting with a hole is installed in its place, the end of which does not touch the shoulder 9 of the partition. A pipeline and then a sampling container are connected to the fitting;
- through the hole 8 insert the lever with a pointed flat end so that the flat end fits into the grooves. Acting as a lever, the partition 4 is moved upward, while the slotted outlet openings 11 are moved above the sealing rings 12, a closed cavity having a high pressure is connected with the external space, liquid and gas flow through the nozzle and pipeline into the container. After filling the container, the partition 4 by means of a lever moves down to the stop of the shoulder 9 at the end of the lower part of the adapter 2, thereby blocking the outlet channel of the liquid and gas. The container is disconnected, the sleeve 4 moves upward in the above manner, and excess liquid and gas are discharged from the closed cavity. Only after a complete release of pressure from the closed cavity can the device be disconnected from the rest of the layout and the rise of the IPT layout can be continued.

 The number of opening and closing cycles of a cavity depends on the number of containers being filled.

Thus, the proposed device allows you to:
- carry out the launch of geophysical instruments through the testing equipment in the process of testing the formation;
- to increase the reliability of depressurization of closed cavities by eliminating clogging of channels;
- to ensure safe conduct of work during depressurization of the cavities of the layout of the test downhole equipment.

Claims (1)

 A device for depressurizing cavities of an assembly of testing downhole equipment, comprising a hollow sub with side channels, a hollow partition installed in the sub, and a cork, characterized in that the hollow sub is made detachable from two parts connected by a thread, lateral channels displaced in the upper part of the hollow sub relative to each other in height, and made an open side hole, the hollow partition is made in the form of a sleeve with a shoulder and is movably and coaxially in the cavity both x parts of the hollow sub, on the outer surface of the upper part of the hollow partition there are two rows of o-rings, between which opposite the open side hole grooves are made to control the device, and outlet holes are made in the lower part of the hollow partition, the plug is installed in the lower side channel with the possibility of contact with the end of the collar of the hollow partition, preventing its spontaneous displacement up, and in the cavity of the hollow sub placed sealing rings for sealing the hollow regorodki with the lower part of the hollow sub.

Images