CN103674147A - On-line measuring device and method for double-flowmeter crude oil water content - Google Patents

Abstract

The invention relates to an on-line measuring device and method for double-flowmeter crude oil water content. The device comprises a flange, a filter, an exhaust valve, a pressure reducing and maintaining valve, a first horizontal pipeline, a volumetric flowmeter, a second horizontal pipeline and a bent pipe. An inlet of the filter is externally connected with a pipeline through the flange, an outlet of the filter is connected with an inlet of the exhaust valve, an outlet of the exhaust valve is connected with an inlet of the pressure reducing and maintaining valve, an outlet of the pressure reducing and maintaining valve is connected with one end of the first horizontal pipeline, the other end of the first horizontal pipeline is connected with an inlet of the volumetric flowmeter, an outlet of the volumetric flowmeter is connected with one end of the second horizontal pipeline, and the other end of the second horizontal pipeline is connected with the bent pipe. According to the on-line measuring device and method for double-flowmeter crude oil water content, the volumetric flowmeter is used for measuring fluid flow at the positions of the horizontal pipelines, and a bent pipe flowmeter is used for measuring the fluid flow at the position of the bent pipe; accuracy and reliability are high, the stability is good, the cost is low, and errors brought by manual measurement are reduced.

Description

On-line measurement device and the measuring method of two-flow meter water content in crude oil

Technical field

The present invention relates to crude oil fields of measurement, particularly relate to a kind of on-line measurement device and measuring method of two-flow meter water content in crude oil.

Background technology

Water content in crude oil directly has influence on that crude oil production, dehydration, collection are defeated, metering, sale, refinery etc., therefore, crude oil produce and the process of accumulating in, all require detection crude oil water content.The online detection of water content in crude oil, for the exploitation life-span of determining well water, withdrawal point, estimation crude production rate, prediction oil well, significant.Meanwhile, water content in crude oil accurately and timely detects data online, can reflect the duty of oil well, and administrative authority is reduced energy consumption, reduces costs, realizes oil field automation management, plays an important role.

China successively develops multiple multi-form crude oil water content tester, drop into after the use of oil field, although obtained certain effect, but due to technique and technical merit reason, its stability, accuracy, real-time, reliability and cost situation, be difficult to adapt to China's high water cut oil field and produce actual requirement.Summary of the invention

Technical matters to be solved by this invention is, overcomes the above-mentioned defect that prior art exists, and provides a kind of accuracy of measurement high, and reliability is high, good stability, on-line measurement device and the measuring method of the two-flow meter water content in crude oil that cost is low.

The on-line measurement device of two-flow meter water content in crude oil, comprises flange, filtrator, vent valve, decompression venting valve, the first horizontal pipe, volumetric displacement meter, the second horizontal pipe and bend pipe.

The import of filtrator is by flange external pipe, the outlet of filtrator is connected with the import of vent valve, the outlet of vent valve is connected with the import of decompression venting valve, the outlet of decompression venting valve is connected with one end of the first horizontal pipe, the other end of the first horizontal pipe is connected with the import of volumetric displacement meter, the outlet of volumetric displacement meter is connected with one end of the second horizontal pipe, and the other end of the second horizontal pipe is connected with bend pipe.

Described pipe bent position is provided with elbowmeter, on the first horizontal pipe between described decompression venting valve and volumetric displacement meter, pressure unit is installed, and on the second horizontal pipe between described volumetric displacement meter and bend pipe, temperature transmitter is installed.

Furtherly, described winding pipe flow rate is counted differential pressure flowmeter, and bend pipe is 90 ° of bend pipes that elbowmeter carries.

The On-line Measuring Method of two-flow meter water content in crude oil, comprises the steps:

1) fluid is flowed through respectively after filtrator, vent valve and is obtained full packages and the less fluid of impurity, the decompression venting valve of flowing through again obtains the fluid of pressure stability, this fluid first horizontal pipe of flowing through enters volumetric displacement meter, then second horizontal pipe of flowing through, and enters elbowmeter.

2) by volumetric displacement meter, measured the flow value q of fluid in two horizontal pipes _v, by elbowmeter, measured the pressure differential Δ p of pipe bent position, thereby obtain the content q of water in oil mixing with water medium _{v water}:

wherein α is the coefficient that actual flow velocity distributes and adopts with forcing the difference of eddy flow, and R is elbow radius, and D is pipe diameter, ρ _oilfor the density of crude oil, ρ _waterfor the density of water, q _vflow value for fluid in two horizontal pipes of volumetric displacement meter measurement.

3) utilize temperature data and the pressure data of temperature transmitter and pressure unit Real-time Collection fluid, and then flow compensated value.

The present invention compared with prior art has following features: by volumetric displacement meter, at horizontal pipe place, measure fluid flow, elbowmeter is measured fluid flow in pipe bent position, accuracy and reliability are high, good stability, cost is low, reduce the error that manual measurement brings, efficiently solved the problem of measuring at the water content in crude oil of middle and high water leg; Adopt temperature transmitter and pressure unit can also effectively reduce error.

Accompanying drawing explanation

Fig. 1 is the structural representation of the on-line measurement device of two-flow meter water content in crude oil of the present invention.

In Fig. 1: 1, flange, 2, filtrator, 3, vent valve, 4, decompression venting valve, 5, pressure unit, the 6, first horizontal pipe, 7, volumetric displacement meter, the 8, second horizontal pipe, 9, temperature transmitter, 10, elbowmeter, 11, bend pipe.

Embodiment

With reference to Fig. 1, the on-line measurement device of two-flow meter water content in crude oil, comprise the filtrator 2 being connected successively with former external pipe, vent valve 3, decompression venting valve 4, the first horizontal pipe 6, volumetric displacement meter 7, the second horizontal pipe 8 and bend pipe 11, be that former external pipe is connected with the import of filtrator 2 by flange 1, the outlet of filtrator 2 is connected with the import of vent valve 3, the outlet of vent valve 3 is connected with the import of decompression venting valve 4, the outlet of decompression venting valve 4 is connected with one end of the first horizontal pipe 6, the other end of the first horizontal pipe 6 is connected with the import of volumetric displacement meter 7, the outlet of volumetric displacement meter 7 is connected with one end of the second horizontal pipe 8, the other end of the second horizontal pipe 8 is connected with bend pipe 11, bend pipe 11 places are provided with elbowmeter 10, on the first horizontal pipe 6 between decompression venting valve and 4 volumetric displacement meters 7, pressure unit 5 is installed, on the second horizontal pipe 8 between volumetric displacement meter 7 and bend pipe 11, temperature transmitter 9 is installed.

The winding pipe flow rate of the present embodiment is counted differential pressure flowmeter, and bend pipe is 90 ° of bend pipes that elbowmeter carries.

By volumetric displacement meter 7, at horizontal pipe place, measure fluid flow, elbowmeter 10 is measured fluid flow in pipe bent position, and accuracy and reliability are high, good stability, and cost is low, has reduced the error that manual measurement brings.

The On-line Measuring Method of two-flow meter water content in crude oil, comprises the steps:

1) fluid is flowed through respectively after filtrator, vent valve and is obtained full packages and the less fluid of impurity, the decompression venting valve of flowing through again obtains the fluid of pressure stability, this fluid first horizontal pipe of flowing through enters volumetric displacement meter, then second horizontal pipe of flowing through, and enters elbowmeter.

2) by volumetric displacement meter, measured the flow value of fluid in two horizontal pipes, by elbowmeter, measured the flow value of pipe bent position fluid; When liquid flows through volumetric flow rate timing, volumetric displacement meter can obtain a volume numerical value that flows through liquid, and this volume is denoted as to q _v.Because liquid has passed through the processing of filtrator, vent valve and decompression venting valve in system, and finally obtained stable fluid, so can think and know under the prerequisite of average fluid density in hypothesis, the flow value q that elbowmeter obtains _v0the flow value q obtaining with volumetric displacement meter _vequate, that is:

q _v0＝q _v

Elbowmeter is a kind of of differential pressure flowmeter.When fluid flows along the curved channel of bend pipe, fluid produces centrifugal force owing to being subject to the effect of angular acceleration, and the outboard tube wall pressure power of bend pipe is increased, thereby makes the poor Δ of mineralization pressure between the interior outboard tube wall of bend pipe _p.Can prove, the square root of this pressure differential is directly proportional to flow.As long as measure pressure differential, just can obtain flow value.

According to forcing eddy flow theoretical, can be in the hope of the flow formula of the fluid volume flow by 90 ° of bend pipes:

$q_{v0}=\mathrm{\α}\sqrt{\frac{R}{2D}}\left(\frac{\mathrm{\π}}{4}{D}^2\right)\sqrt{\frac{2\mathrm{\ΔP}}{\mathrm{\ρ}}}=C\left(\frac{\mathrm{\π}}{4}{D}^2\right)\sqrt{\frac{2\mathrm{\ΔP}}{\mathrm{\ρ}}}$

In formula,

for coefficient of flow, α is the coefficient of considering that actual flow velocity distributes and adopts with forcing the difference of eddy flow, and its numerical value generally depends on the position of pressure tappings.In the present embodiment, due to the buying instrument of elbowmeter, so α is definite value.

In formula, Δ _pfor pressure differential, be the parameter that elbowmeter directly records, the density p that flows through medium in pipeline is unknown number, need to derive:

By (2) formula $q_{v0}=\mathrm{\α}\sqrt{\frac{R}{2D}}\left(\frac{\mathrm{\π}}{4}{D}^2\right)\sqrt{\frac{2\mathrm{\ΔP}}{\mathrm{\ρ}}}=C\left(\frac{\mathrm{\π}}{4}{D}^2\right)\sqrt{\frac{2\mathrm{\ΔP}}{\mathrm{\ρ}}}---\left(3\right)$

Can obtain: ${q_{v0}}^2=C^2{\left(\frac{\mathrm{\π}}{4}{D}^2\right)}^2\frac{2\mathrm{\Δp}}{\mathrm{\ρ}}---\left(4\right)$

$\mathrm{\ρ}=C^2{\left(\frac{\mathrm{\π}}{4}{D}^2\right)}^2\frac{2\mathrm{\Δp}}{{q_{V0}}^2}=\frac{\mathrm{K\Δp}}{{q_{v0}}^2}---\left(5\right)$

Wherein $K=2C^2{\left(\frac{\mathrm{\π}}{4}{D}^2\right)}^2$

(1) formula is brought in (5) formula, can obtain:

$\mathrm{\ρ}=\frac{\mathrm{K\Δp}}{{q_v}^2}---\left(6\right)$

Wherein, in K, parameters is known, so K can regard known quantity, Δ as _pfor pressure differential, by elbowmeter, recorded q _vvolume for measured, is recorded by volumetric displacement meter, Gu the density of medium can obtain, by (6) formula, represents.

When institute's fluid measured flows through flowmeter, the gross mass that flows through medium is constant, so have:

Q _m=q _{m water}+ q _{m oil}(7)

Have

ρ q _v=ρ _waterq _{v water}+ ρ _oilq _{v oil}(8)

In formula, q _mfor the gross mass of medium, q _{m water}and q _{m oil}be respectively the quality of water and oily quality, q _{v water}and q _{v oil}be respectively the volume of water and oily volume.

The cumulative volume that flows through medium is also constant, has:

Q _v=q _{v water}+ q _{v oil}(9)

By (8) formula and (9) formula simultaneous:

Obtain: (ρ-ρ _oil) q _v=(ρ _water-ρ _oil) q _{v water}(11)

That is:

Wherein:

q _vrecord ρ _waterand ρ _oilall can differ from table and draw, be known number, so by (6) formula and C, K difference substitution (12) formula, the content of water in the oil mixing with water medium that can obtain flowing through in pipeline.

The method for expressing of this liquid water content is:

3) utilize temperature data and the pressure data of temperature transmitter and pressure unit Real-time Collection fluid, and then flow compensated value.

Claims (3)

1. the on-line measurement device of two-flow meter water content in crude oil, comprises flange, filtrator, vent valve, decompression venting valve, the first horizontal pipe, volumetric displacement meter, the second horizontal pipe and bend pipe, it is characterized in that:

The import of filtrator is by flange external pipe, the outlet of filtrator is connected with the import of vent valve, the outlet of vent valve is connected with the import of decompression venting valve, the outlet of decompression venting valve is connected with one end of the first horizontal pipe, the other end of the first horizontal pipe is connected with the import of volumetric displacement meter, the outlet of volumetric displacement meter is connected with one end of the second horizontal pipe, and the other end of the second horizontal pipe is connected with bend pipe;

Described pipe bent position is provided with elbowmeter, on the first horizontal pipe between described decompression venting valve and volumetric displacement meter, pressure unit is installed, and on the second horizontal pipe between described volumetric displacement meter and bend pipe, temperature transmitter is installed.

2. on-line measurement device as claimed in claim 1, is characterized in that: described winding pipe flow rate is counted differential pressure flowmeter, and bend pipe is 90 ° of bend pipes that elbowmeter carries.

3. utilize device described in claim 2 to carry out the On-line Measuring Method of two-flow meter water content in crude oil, it is characterized in that comprising the steps:

1) fluid is flowed through respectively after filtrator, vent valve and is obtained full packages and the less fluid of impurity, the decompression venting valve of flowing through again obtains the fluid of pressure stability, this fluid first horizontal pipe of flowing through enters volumetric displacement meter, then second horizontal pipe of flowing through, and enters elbowmeter;

2) by volumetric displacement meter, measured the flow value q of fluid in two horizontal pipes _v, by the pressure differential Δ of elbowmeter measurement pipe bent position _pthereby, obtain the content q of water in oil mixing with water medium _{v water}:

wherein α is the coefficient that actual flow velocity distributes and adopts with forcing the difference of eddy flow, and R is elbow radius, and D is pipe diameter, ρ _oilfor the density of crude oil, ρ _waterfor the density of water, q _vflow value for fluid in two horizontal pipes of volumetric displacement meter measurement

3) utilize temperature data and the pressure data of temperature transmitter and pressure unit Real-time Collection fluid, and then flow compensated value.

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