SU1754890A1 - Device for quality control of cementation of big-diameter casing strings - Google Patents

Abstract

Use: area of geophysical research. The essence of the invention: providing more optimal conditions for clamping the measuring units of the borehole geophysical instrument due to the use of the own weight of the measuring units and independent operation of the upper and lower hinge-lever units of the pressing of the measuring units. The device includes a housing 1 connected to the candle bridge 2. With the housing 1 there is a rigidly connected guide rod 3, on the latter there are movable supports 4-7 with hinged upper and lower levers 8-11 and contact rollers 12 The measuring units 13 are fixed between the axes of the rollers 12, and springs 14-17 of a given rigidity and working stroke are installed under the lever supports. When the device is lowered, the spring 17 is compressed by the mass of the moving part of the block 13 suspension. Under the action of the mass, the device is immersed into the well, while the soft springs 14, 15 and 16 work out the entry profile. Independent folding and opening of the upper and lower paired levers 8-11 reduces the impact of shocks and vibrations on the contact rollers 12, working out the effect of their soft springs 15 and 16.2 Il. Fig 2

Description

The invention relates to geophysical studies and can be used to control the quality of cementing large-diameter casing strings by the method of scattered gamma radiation.

Known downhole logging complex containing a logging cable, downhole tool and centralizer device for fixing the downhole tool along the axis of the well while pressing the device levers with electrodes mounted on them to the borehole wall,

The lever centralizer, located on the downhole tool, provides, regardless of the relief, changing diameter and inclination of the well, the central position of the instrument in the cross section of the well and the necessary contact of the centralizer levers with the walls of the well.

The rigidity of the lever centralizers for holding the weight of the device with a cable reduces the vibration and impact ability of the device and increases the likelihood of the device jamming when complex control and actuating devices fail under conditions of corrosive well conditions.

A well logging complex is known, which includes a wireline cable, a well tool attached to the cable, and a device for fixing the position of the well tool in the cross section of the well, such as a centralizer or a clamping device. A device for fixing the position of a well device in the cross section of a well is installed with the possibility of its longitudinal movement relative to the cable in the area bounded below by the well tool, from above - additionally introduced by the stop-pusher.

Introducing a weak centralizer on a wellbore device improves working conditions during shocks and vibrations, but a weak centralizer in this logging complex works only when the device is lowered, and when it is raised, the device is joined to a rigid centralizer located on the cable through which beats and vibrations arising in the well string are transmitted directly to the instrument, reducing its vibration and impact. A hard centralizer, in addition to the foregoing, always increases the likelihood of it jamming in a well with a variable diameter at the junction of the pipes of the column and at the places of bending of the column when going to a new angle of inclination.

Closest to the present invention is a device comprising a housing movably connected to a candlestick bridge, spring-loaded articulated-lever-type centralizers with contact rollers, measuring units located on

forming a cylindrical surface inscribed with a gap in the casing, and hinged on the axes of the contact rollers.

The disadvantage of the known device is concluded in the design of the centralizer. The centralizer contains springs, linking in pairs the levers of the upper and lower support rollers. To hold the measuring units on the generator cylindrical

the surface stiffness of at least one of the springs must be equal to the total normal component force of the weight of the moving part of the lever system, i.e. in the lever where there is a stiff spring arises

a contact for transmitting shock and vibration to the body of the measuring device, which reduces its shock and vibration abilities, and also increases the likelihood of the device getting stuck in the well.

The purpose of the invention is to improve the throughput of the device on the casing and increase the vibration resistance of the measuring units.

The positive effect of the use of

of the invention is also due to the extended range of casing research, while skipping the device can operate both at maximum opening and in the folded state, without

no additional installation work.

The goal is achieved by the fact that in a device comprising a housing with a guide rod that is movably connected to

the cable placed on the rod movable supports, to which the lower and upper paired levers with contractual rollers are hinged, between which axes the measuring blocks are fixed, are mounted springs, one of which is installed under the lower movable support of the paired lower levers and is made with stiffness determined by condition Fi G + FConp.,

two are under the lower and upper movable supports of the upper twin levers and are made with stiffness determined by the condition

51ploz7g (-p + s-51)

and one - under the upper movable support of the lower twin levers and is made with stiffness determined by the condition

F3 Jj F2,

where Fi, F2, P3 are spring compressive forces, H;

G is the reduced total weight of the measuring units, N

Fconp is the resistance force when the device is moving, N;

a is the permissible angle between the generator of the lever and the guide rod under the condition of maximum opening of the device in the column, degrees;

n is the number of measuring units;

B- permissible angle of inclination of the well axis, degrees;

FH is the normal component of the force acting on the column, H,

Using the own weight of the measuring units to press them against the walls of the well string by opening the levers allows you to go from the centering system to the device's axis to the elastic suspension system and pressing the device’s measuring blocks to the walls of the casing in the well Springs in the known device ensure the operation of the centering devices, the latter is rigid centering the axis of the device relative to the axis of the casing The suspension system of the measuring units allows the arms to be opened and folded waist portion of the device relative to the lower arm paired lower support, providing a constant nip measuring units against the wall of the column spring mounted under the bottom support lower paired lever is a bearing and has a stiffness selected from conditions - Fi G + Fconp,

which eliminates the possibility of the instrument sagging on the vertical section of the well and at the same time eliminates the rigid support in the suspended part of the device, providing an elastic suspension. Work force additional springs selected from the following conditions:

sin a cos a

 (n FH + G sin (9)

iRz J

F2

The conditions are determined by the need to provide a predetermined normal component force to press the inclined rollers against the walls of the column in the well in the vertical section, which ensures the rotation of the measuring units relative to the axis of the well and eliminates the possibility of the inclined rollers slipping when lifting the device, and the need to prevent the device from being suspended set well slope

The use of the own weight of the measuring units to press the latter against the walls of the casing allows the use of soft springs to create

additional efforts to hold the support rollers against the walls of the casing string in the well and to make the suspension of the measuring blocks elastic. Thus, shocks and vibrations occurring in the column and affecting the lower roller are extinguished on the soft spring mounted above the upper support of the lower lever, and those acting on the upper roller are extinguished on the soft springs installed under the support of the top 5 paired lever. .

Fig. 1 shows a kinematic diagram of the proposed device, and Fig. 2 shows a downhole tool.

The device (figure 1) includes a housing 1

0 of the device, electrically and mechanically connected to the candle bridge 2. A guide rod 3 is rigidly connected to the body, on which supports 4-7 of the upper and lower paired levers 8-11 are mounted, hinged

5 fixed on the axis inclined rollers 12, between which the measuring units 13 are installed. Under the supports there are springs 14-17, the stroke of which is limited by the stops 18-21. Opportunity provided

0 free rotation of the housing 1 relative to the candlestick bridge 2.

The device works as follows.

When the device is lowered into the casing column, the device is in a vertical position, it is opened, while the spring 17 is compressed by the weight of the movable part of the suspension of the measuring units 13. The levers 11 are opened relative to the support 7. Supports 4.5 and 6 levers 8.9 and 10 are displaced along the guide rod 3. The protruding edge of the casing slides along the lever 7 to the contact rollers.

5 12. Under the action of its own weight, the device is immersed in the well, with soft springs 14. 15 and 16 work out the entry profile. The device on the cable is lowered to a predetermined depth, where it is located in

0 free equilibrium state, the weight of the movable part of the suspension of the measuring blocks 13 together with the spring forces of 14, 15 and 1 b ensures maximum opening of the movable part of the suspension under the condition of minimal effort to press the inclined rollers 12 to the walls of the well string. Measurement takes place during lifting of the device. When measuring, the device moves along the wellbore, with the inclined rollers 12,

in contact with the casing wall of the well, the device body 1 is brought into rotational movement. The twisting forces are extinguished on the candle bridge 2. The measuring blocks 13 describe the spiral components during lifting, depending on the angle of inclination of the rollers 12. Moving supports 4, 5 and 6 the levers 8, 9 and 10 slide along the guide rod 3, working out, together with the soft springs 14, 15 and 16, possible transitions and joints of the column, excluding the possibility of jamming of the device. The possibility of independent folding and opening of the upper and lower paired levers 8, 9, 10 and 11 reduces the impact of shocks and vibrations on the contact rollers 12, working out the effect of their soft springs 15 and 1S. The detectors of the measuring units record the intensity curves of the scattered gamma radiation around the perimeter of the column and the depth of the cement. From the measuring units, the signals go to the conversion unit located in the instrument case 1 and are transmitted to the surface via a cable.

The invention is illustrated with a downhole tool for monitoring the quality of cementing conductors and large diameter technical columns developed at VNIIneftepromgeofizika.

Figure 2 presents Pribo, General view. The device contains a sealed housing 1, inside of which is placed the electronic unit of the device with attached hermetic electrical leads 4; a guide rod 3 connected by means of a cap nut 2 to the housing 1; a hinge-lever system mounted on the guide rod 3 and containing levers 19 and 20, 20 and 23 connected on one side to the supports 5, 13, 25 and 26, made in the form of sleeves and mounted on the guide rod 3. on the other hand levers 19 and 20. 20 and 23 are paired on supports 8 and 10, on which the support rollers 11 are fixed; a drive system made in the form of springs 6,16-18 and drive rods 12 and 15 connected to support sleeves of a hinged-lever system, which are mechanically driven by three identical measuring shoes 9 fixed on supports 8 and 10. Inside the shoe there is a radioactive source 27, the receiving electronic conversion unit and a protective screen with collimation windows; protective tip 14 with a shock-absorbing rubber sleeve 24.

Claims (1)

Claims An apparatus for monitoring the quality of cementing large-diameter casing strings comprising a housing with a guide rod, movably connected to a cable, movable supports placed on a rod, to which are hingedly attached lower and upper coupled levers with contact rollers, between which axes the measuring blocks are fixed, characterized in that, in order to improve the permeability of the device along the casing string and increase the vibro impact strength of the measuring blocks, it is equipped with springs, one of which is installed under the lower movable support of the paired lower levers and is made with stiffness definable condition Fi G + FCOnp two are under the lower and upper movable supports of the upper twin levers and are made with stiffness determined by the condition F2 sina1cos "- (n-F + G-sin) - and one - under the upper movable support of the lower twin levers and is made with stiffness determined by the condition Rz 2 P2. where FI, F2, Pz is the spring compressive force, H; G — reduced total weight of measuring blocks, N; Fconp is the resistance force when the device is moving, N; a is the permissible angle between the generator of the lever and the guide, subject to the maximum opening of the device in the column, degrees; n is the number of measuring units; B- permissible angle of inclination of the borehole axis, degrees; FH is the normal component of the force acting on the column. N. 20