RU2496101C1 - Device for sampling of liquid from pipeline - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: device includes sampling tube mounted in pipeline perpendicular to flow movement and provided with slot-like inlet from side of flow movement. Slots in inlet are made horizontally along the height of pipeline and are directed toward liquid flow. Depth of slots changes from small near pipeline walls to largest near pipeline axis. Opposite to inlet in sampling tube there made is a vertical slot.

EFFECT: increasing sample uniformity and improving accuracy of sample composition determination.

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Description

The invention relates to the oil industry and may find application in sampling liquid from a pipeline.

A device for sampling liquid from a pipeline, including sampling tubes mounted vertically along the diameter of the pipeline. The axis of the tube holes are parallel to the axis of the pipeline and directed towards the flow. The opposite ends of the tubes enter the mixing chamber, from which the selected sample enters the quality block. The diameters of the selected tubes satisfy the ratio 13: 10: 6: 10: 13 (Sampler. GOST 2517-85 (Clause 2.13, Figure 15).

However, the known device has a low representativeness of the samples taken.

A device is known for sampling liquid from a pipeline, containing a sampling tube mounted in the pipeline perpendicular to the flow movement and having an inlet opening of a slit-like shape on the side of the flow movement, the profile of which is selected from the condition that liquid from the pipeline is supplied under excess pressure in proportion to its flow rate at each elementary horizontal section pipeline with the same coefficient of proportionality and with an average speed at the entrance to the sampling pipe equal to the average speed awns flow in the conduit (USSR Author's Certificate №1700424, Cl. G01N 1/10, 1991).

However, in the known device, the sampling element has a large metal consumption, and also its hydraulic resistance is quite large. In the known device, a flow rate stabilizer is installed in the sampling tube, however, this placement of the stabilizer reduces the flow area of the sampling element and increases the hydraulic resistance. As a result, it may be technically difficult to provide isokinetic sampling (especially at high pipeline flow rates). And the high quality of the sample obtained with this can not always be guaranteed.

Closest to the proposed invention in technical essence is a device for sampling fluid from a pipeline, including a sampling tube mounted in the pipeline perpendicular to the flow movement and having an inlet slot-shaped on the side of the flow direction, the profile of which is selected from the condition of flowing under excess pressure of the liquid from the pipeline in proportion to its flow rate at each elementary horizontal section of the pipeline with the same proportionality coefficient, with Independent user rate at the inlet of the sample probe tube, equal to the average flow velocity in the piping diameter and length of the sample probe tube selected from the ratio 1: (12-30) (Russian Patent №2085893, published 27.07.1997 - a prototype.).

A disadvantage of the known device is a violation of the kinetics of fluid flow in the pipeline, the accumulation of the oil phase in the device, which distorts the composition of the sample and leads to inaccuracies in determining the composition of the sample.

The proposed invention solves the problem of increasing the uniformity of the sample and thereby increasing the accuracy of determining the composition of the sample.

The problem is solved in that in the device for sampling fluid from the pipeline, including a sampling tube mounted in the pipeline perpendicular to the flow movement and having an inlet slotted in the direction of flow, according to the invention, in the inlet of the slotted shape, the slots are made horizontally along the entire height of the pipeline and directed towards the fluid flow, the depth of the slots varies from shallow near the walls of the pipeline to the largest near the axis of the pipeline, opposite the inlet into the sample the intake pipe has a vertical gap.

SUMMARY OF THE INVENTION

The efficiency of developing a productive formation, the profitability of well operation, timely decision-making on processing the bottom-hole zone of a well, repairing a well, evaluating the effectiveness of new technologies are directly related to obtaining reliable information about the oil and water content in the produced well products. The solution to the problem of constant monitoring of the oil and water content in the well’s production is still relevant despite the currently available technical solutions to this problem. Existing slotted sampling devices are oriented towards the fluid flow. The disadvantages of these devices are the incomplete coverage of the liquid section, the lack of through flow, which entails the deposition of oil in the device.

The main conditions for the selection of a high-quality sample of well production is sampling from the entire cross section of the fluid flow in the pipeline in a uniform or mixed flow, without disturbing the kinetics of movement, without accumulating the oil phase in the sampling device itself. The proposed device solves the problem of increasing the uniformity of the sample and thereby increasing the accuracy of determining the composition of the sample. The problem is solved by the device shown in figures 1-4.

A device for sampling liquid from a pipeline includes a sampling tube 1 mounted in the pipe 2 perpendicular to the movement of the stream 3 and having an inlet in the form of horizontal slots 4 from the side of the flow 3. The horizontal slots 4 are made horizontally along the entire height of the pipeline 2. The depth of the horizontal slots 4 varies from small 5 near the lower and upper points to the largest 6 near the axis of pipeline 2. Opposite the horizontal slots 4 in the sampling tube 1 there is a vertical gap 7.

Under the location of the sampling tube 1, a sleeve 8 is welded to the pipe 2 with the formation of a weld 9. A sampling tube 1 is screwed onto the sleeve 8. The sampling tube 1 is provided with a lockable lock nut 10 with a mark 11. Mark 11 and horizontal slots 4 are directed towards the flow of the production well 3. Sampling the valve 12 is screwed onto the outlet fitting 13 of the sampling tube 1, which is in communication with the internal volume 14 of the sampling tube 1.

The device operates as follows.

Install the device. The well is stopped. On the flow line 2 wells at the installation site of the device cut a "window". Under the cut hole in the body of the pipeline 2, a sleeve 8 is welded by a weld 9. A sampling tube 1 is screwed onto the sleeve 8. The sampling tube 1 is installed exactly according to the mark 11 and counter-nut 10. The mark 11, and therefore the horizontal slots 4, are directed towards the flow of the well production 3. On the outlet fitting 14 of the sampling tube 1, a sampling valve 12 is screwed. The well is put into operation, the tightness of the weld point 9 and the sampling tube 1 is checked. The flow of production from the well 3 passes through horizontal slots 4 and vertical gap 7. In this case, the laminar flow transitions to turbulent. Mixing of the layers of the flow, normalization of the flow. Sampling of the products of the well 3 is carried out by opening the sampling valve 12 and draining the products of the well 3 into standard glassware (not shown). When opening the sampling valve 12, the production of the well 3 passes through horizontal slots 4, the internal volume 14 of the sampling tube 1, the sampling valve 12 into standard glassware, and at the same time part of the flow passes through the vertical slot 7. Sampling is carried out from the entire cross section of the flow of the production of the well 3, without disturbing the kinetics of motion. After sampling, the sampling cock 12 is closed.

The proposed device achieves high uniformity of the sample and thereby increases the accuracy of determining the composition of the sample. Due to the presence of horizontal and vertical slots, the kinetics of the fluid flow in the pipeline is preserved, there is no accumulation of the oil phase in the device.

The choice of device size depends on the flow rate of the well and is determined based on the possibility of creating a turbulent flow in the sampling zone, depending on the calculated flow area for the nominal diameter of the pipeline and the volume of fluid.

Concrete example

It is known that a turbulent fluid flow is provided at a Reynolds number Re≥2320, which is determined by the formula:

R _e = V * D / v,

where V is the fluid velocity, m / s,

D is the diameter of the pipe, m,

v is the kinematic viscosity, m ² / s.

V = Q _w / S * 86400,

where Q _W - flow rate of the passing fluid, m ³ / day,

S is the cross-sectional area of the pipe, m ² ,

S = π * D ² /4=0.785*D ²

v = µ _w / R _w ,

where µ _W is the dynamic viscosity of the liquid, Pa * s,

ρ _W - liquid density kg / m ³ .

The dynamic viscosity of oil is known for each development object in MPa * s (Pa * s * 10 ^-3 ). There is no unambiguous determination of fluid viscosity (µ _g ) by calculation; all formulas are approximate and depend on the properties of oil, water and gas in the well’s production. Therefore, in the calculations when determining the selection criteria for the device and the installation location at the wellhead, depending on the flow rate of the well, the viscosity of the fluid µ _{w is} taken to be ≈ 15 * 10 ^-3 Pa * s.

Reynolds number after conversion:

R _e = V * D / v = V * D * ρ _W / μ _W = 4 * Q _W * ρ _W / π * D * μ _W * 86400 = Q _W * μ _W / D * μ _W * 67824

The nominal diameter of the pipeline in the sampling zone is determined from the calculation of the free flow cross section after installing the sampling tube: D _y = (√S _tp -S _ЩПЗ + S _{в. ЩПЗ} / 0.785) mm or D _y = (√S _Тр -ΔS _щпз / 0.785) ,

where S _TP - pipe section without sampling tube, mm ² ,

S _ЩПЗ - section of a sampling pipe overlapping the total pipe section, mm ² ,

S _{V. SCHPZ} - section of the vertical slit of the sampling tube, output, mm ² .

S _tp = π * D _tp ² /4=0.785*D _tp ² ;

_Schpz S ₃ = h * d _n.schpz or _schpz S = D _{ext. tp} * d _n .

where h ₃ is the height of the sampling tube ≈ D _{int.trv to the} inner diameter of the pipe, mm,

d _{N. shchpz} - the outer diameter of the suction tube, mm,

S _in.shchpz - L _in In _shch ,

where L _in - the height of the vertical gap, mm,

in _u - the width of the vertical gap, mm

or D _y = (√0.785 * D _in.tr ² -D _in.tp * d _N.schpz + L _in * in _u / 0.785) mm.

Criteria for the use of various devices for fluid sampling (slotted intakes) depending on the flow rate of the well.

1. Slot-hole inlet - 100, the installation location of the wellhead manifold, the diameter of the pipeline is 100 mm.

Initial data:

D _Tr = 100 mm; dn _schpz = 24 mm; d _in.shchpz = 18 mm; L in. _SCHPZ = 93 mm; in _u = 3 mm; s _u = 3 mm - step

horizontal slots.

D _y = (√0.785 * 100 ² -100 * 24 + 93 * 3 / 0.785) = 85 mm,

then Q _w.min = 2320 * 0.085 * 15 * 67.824 / 1000 = 200 m ³ / day;

when µ _W = 15 * 10 ^-3 Pa * s ρ _W = 1000 kg / m ³ .

2. Slot-hole inlet - 50, the place of installation - fittings or manifold of the wellhead, the diameter of the pipeline is 50 mm.

a) D _Tr = 50 mm; dn _schpz = 16 mm; d _v.schpz = 10 mm; L in. _SCHPZ = 46 mm; in _u = 2 mm; s _u = 2 mm is the step of horizontal slits.

D _y = (√0.785 * 50 ² -50 * 16 + 46 * 2 / 0.785) = 40 mm

Q _w.min = 2320 * 0.04 * 15 * 67.824 / 1000 = 94 m ³ / day

b) dн _щпз = 22 mm; d _in.shchpz = 18 mm; L in. _SCHPZ = 25 mm; in _u = 2 mm; s _u = 3 mm.

D _y = (√0.785 * 50 ² -50 * 22 + 25 * 2 / 0.785) = 34 mm

Q _w.min = 80 m ³ / day

Methods for calculating gaps

Depending on the flow rate of the liquid, water cut of the product, pressure in the pipeline, the installation location of the slotted sampling probe, the outer and inner diameter of the sampling tube, the number of horizontal slots, their width and the pitch between the slits, and the height and width of the vertical slit are selected.

The areas of horizontal slots are calculated from the condition of proportionality of the area of fluid flow over the cross section of the pipe to the areas of the slots of the sampling tube, respectively, at the levels of the planned horizontal slots (horizontal planes).

The proportionality coefficient of the cross section of fluid flows in the pipeline and in the sampling tube relative to the center of the pipeline is determined:

K _s = _{s of schpz} / S _p * = L in _o.schpz / D * _o.tr in _o.schpz = L / D _TP = π * r _{ext. schpz} / D _tp

where D _about = D _tp - the inner diameter of the pipeline, mm

L _o.shchpz - the length of the semicircle of the gap along the inner radius relative to

the center of the pipeline, mm

r _{ext. shchpz} - the internal radius of the sampling tube, mm

c - the planned slit width, as well as the imaginary width of the fluid flow at this level, mm.

1. The chords of the cross section of the pipeline, located on the same horizontal plane with horizontal slots, are determined

where x _o = D _o = D _TP and accordingly x _i from the 1st to N slots.

2. The lengths of the semicircles of horizontal slots are determined:

L _{i =} k _s * x _i

3. In the manufacture of a sampling tube in a workshop, it is necessary to calculate the distance shown in FIG. 4 for each horizontal slit:

- from the center of the sampling tube to the slit slit h _i,

- from the outer radius of the sampling tube to the slit Δh,

and the chord of the horizontal slit a _i ,

 determined by the formulas:

h _i = r _ext . _schpz * s _in {90- (L _i * 90 / π * r _{ext. schpz} )}, mm.

Δh _i = r _nar.shchpz -h _i , mm.

$$a_i{a}_i=2*(\sqrt{\Delta h_i*(2*}{r}_{\mathrm{at}n}-\Delta h_i)),mm$$

4. The height of the vertical slit is assumed to be within L _century ~ 0.92-0.93 D _tr , and the width of the vertical gap should not be greater than the width of the horizontal slots.

The calculation results are summarized in a table, for example, for a slotted sample probe -100 (see table No. 1).

Table number 1 ЩП3-100 D _Tr = 100 mm d _nap = 24; d _int = 18; N _u = 17; in _g = 3; in _in = 3; s _g = 3; L _total = 93 No. p / p Slot number Chord pipe
x _i Slit Length (Horizon)
L _i h _i Δh _i a _i Note one 8 26 7 8.2 3.8 6.9 2 7 fifty fourteen 6.4 5.6 12.6 3 6 65 eighteen 4.7 7.3 15.2 four 5 75 21 3.5 8.5 16.5 5 four 85 24 2.2 9.8 17.4 6 3 90 25 1.5 10.5 17.7 7 2 95 26 0.8 11.2 17.8 8 one 98 27 0.4 11.6 17.9 9 0 one hundred 28 0 12 eighteen 10 one 98 27 0.4 11.6 17.9 eleven 2 95 26 0.8 11.2 17.8 12 3 90 25 1.5 10.5 17.7 13 four 85 24 2.2 9.8 17.4 fourteen 5 75 21 3.5 8.5 16.5 fifteen 6 65 eighteen 4.7 7.3 15.2 16 7 fifty fourteen 6.4 5.6 12.6 17 8 26 7 8.2 3.8 6.9

Similarly, calculations are carried out for other standard sizes of slotted inlets.

When using the claimed device, an exact coincidence of multiple measurements with the data of control samples taken during the stoppage of the fluid flow in the pipeline and selection for analysis of part of the volume of the stopped fluid was revealed.

The application of the proposed device will solve the problem of increasing the uniformity of the sample and thereby improve the accuracy of determining the composition of the sample

Claims (1)

A device for sampling liquid from a pipeline, including a sampling tube mounted in the pipeline perpendicular to the flow movement and having a slot-shaped inlet on the flow side, characterized in that in the inlet slots are made horizontally along the entire height of the pipeline and are directed towards the liquid flow, the depth of the slots varies from shallow near the walls of the pipeline to the greatest near the axis of the pipeline, opposite the inlet in the sampling tube, a vertical gap is made e.

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