RU2213949C1 - Procedure of liquid sampling from pipe-line - Google Patents

Abstract

FIELD: technique of taking liquid samples from pipe-line. SUBSTANCE: procedure can be used in oil production and other branches of industry where high precision in determination of parameters of liquid pumped through pipe-line is required. In compliance with proposed procedure sample taking element is installed in pipe-line in which liquid flow changes direction or into which liquid flow is fed from another pipe-line or system of pipe-lines with change of direction of flow. For prevention of stratification of liquid flow after passage through sections of pipe-line bend under action of inertial or gravitational forces in zones of stagnation liquid flow is subjected to mixing with subsequent taking of representative samples. EFFECT: high accuracy with qualitative and quantitative metering of liquid pumped over pipe-line carried out by assemblage of parameters. 1 dwg, 1 tbl

Description

 The invention relates to technology and techniques for sampling fluid from a pipeline and can find application in oil and other industries where high accuracy is required for determining the parameters of the fluid pumped through the pipelines.

 There is a method of sampling liquid from a pipeline, in which a sampling element is placed in the pipeline from one sampling tube with a bent end, which is placed on the axis of the pipeline with an inlet facing the flow and sampling is proportional to the flow rate of the pipeline, at which the sampling rate is chosen equal to the average speed pipeline flow [1].

 A known method of sampling liquid from a pipeline, in which a sampling element is placed in the pipeline from one sampling tube with a bent end, which is placed on the axis of the pipeline with an inlet opening towards the flow and sampling is proportional to the flow rate of the pipeline, at which the sampling rate is at least half and no more than double the average flow rate of the pipeline [2] (prototype method).

 A disadvantage of the known sampling technologies is the low representativeness of the sample in sections of the pipeline where the flow changes direction. When the direction of the flow changes, its heavier phase, for example, water in the oil flow, under the influence of inertial forces is redistributed to the wall of the pipeline. The uniformity of the distribution of inclusions in the cross section of the flow changes, and the flow is stratified. Therefore, a sample taken after changing the direction of flow is not representative.

 The technical result of this invention is to increase the representativeness of the sample taken.

 To achieve a technical result in a method for sampling liquid from a pipeline, which includes placing a sampling element in a pipeline, the liquid in which it changes direction or into which it flows from another pipeline or pipe system with a change in direction of movement, according to the invention, the pipe flow is subjected to sampling before sampling to confusion.

 In the inventive method, a stream prone to delamination after passing sections of rotation under the influence of inertial forces or gravitational in the stagnant zones of the piping system is mixed. Sampling from after mixing the flow provides a more representative sample than the prototype method [2].

 Thus, the implementation of the above operations of the proposed method will allow, in comparison with the prototype method [3] to increase the representativeness of the sample.

 The application of the proposed method will allow for more accurate quantitative and qualitative metering of the fluid pumped through the pipelines, carried out by the totality of parameters, to reduce losses during commercial operations.

 The inventive method of sampling fluid from a pipeline can be specifically applied, for example, in the oil fields - at commercial oil metering stations.

 The inventive method of sampling fluid from the pipeline is as follows.

 In a pipeline, the liquid in which the direction of movement has changed or into which the fluid flow comes from another pipeline or system of pipelines with a change in the direction of flow, before sampling, the flow is mixed, and then a sample is taken. The sample taken in the sampler is sent for analysis - determination of the relative content of ballast in the sample.

 The invention is illustrated in the drawing.

 The drawing shows one of the variants of the device for implementing the proposed method, sampling.

A device for sampling liquid from the pipeline 1 includes a sampling element 2, installed behind the plot of rotation 3 by 90 ^o after the mixer 4, a valve 5 installed on the output node 6 of the sampling element 2, the sampler 7.

 A device for sampling liquid from a pipeline, see drawing, is intended for sampling from a stream of pipeline 1 under the influence of excess pressure in the pipeline relative to atmospheric. The mixer 4 restores the uniformity of the stream after its separation in the turning section 3 of the pipeline 1. The valve 5 serves to control the sampling rate in the sampler 7.

 A device for sampling fluid from a pipeline, see drawing, operates as follows.

When transporting the stream through the pipeline 1 after changing the direction of fluid flow by 90 ^o in the mixer 4, the stream is mixed. Then carry out the sampling through the sampling element 2. The sampling speed is regulated using a valve 5. The sample taken in the sampler 7 is sent for analysis.

 For testing, a device was used for sampling fluid from a pipeline, see the drawing, with the parameters given below.

Pipeline 1 is horizontal with a diameter of 159 mm. The liquid of the pipeline 2 was an oil emulsion with an average water content of 10-35% vol .; the viscosity of anhydrous oil at 20 ^o C was 8-12 cP; flow rate in the pipeline 2 m / s. The sampling element 2 was a tube with an inner diameter of 6 mm, the bent end of which is oriented towards the flow and is located on the axis of the pipeline 1.

 Comparative tests of the proposed method of sampling fluid from the pipeline were carried out using the sampling method [2] and the device, see the drawing, in which sampling is carried out through the sampling element 8, installed before the mixer 4 after the plot of rotation 3 at a distance of 300 mm after rotation flow (section 3). The same sampling elements 2 and 8 were used (element 8 was a tube with an inner diameter of 6 mm, the bent end of which is oriented towards the flow and is located on the axis of the pipeline 1). To control the sample was also taken to the plot of rotation 3 through sampling element 9, similar to 2 and 8.

 The data of comparative tests of the table (columns 3, 4, 5) show that the properties of the stream after it passes through the turn section 3 change to the turn section 3 of the pipeline 1 (column 5 of the table) and after the turn section before mixing (column 4) and are restored after mixing flow in mixer 4 (column 3). Thus, the test data confirm that sampling from the pipeline flow according to the claimed method, in contrast to sampling according to the prototype [2], provides a more representative sampling. Thus, the mixing of the stream after its separation in the turning section 3 restores the uniformity of the distribution of inclusions in the cross section of the stream and ensures the selection of a representative sample.

 The inventive sampling method is industrially applicable, it does not require a major reconstruction of existing metering units for liquids pumped through pipelines, and the changes necessary to implement the claimed technique can be carried out by the manufacturers who service these systems.

Sources of information
1. Oil and oil products, GOST 2517-85, clause 2.13.1.2.

 2. The same, clause 2.13.1.3.

Claims (1)

 A method of sampling liquid from a pipeline, in which a sampling element is placed in a pipeline, the fluid flow in which changes direction or into which it comes from another pipeline or piping system with a change in the direction of flow, characterized in that to eliminate the separation of the fluid flow after passing sections of the pipeline turning under the influence of inertial or gravitational forces in stagnant zones, the fluid flow is mixed with the subsequent selection of Yelnia samples.

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