Tube sampler capable of realizing under-pressure sampling, isothermal sampling and anti-shear sampling, and sampling method

Abstract

The invention relates to the technical field of low-viscosity crude oil pipeline conveying equipment, in particular to a tube sampler capable of realizing under-pressure sampling, isothermal sampling and anti-shear sampling, and a sampling method. In the tube sampler capable of realizing under-pressure sampling, isothermal sampling and anti-shear sampling and the sampling method, the tube sampler comprises a bypass pipeline which is arranged in an inclined way relative to the horizontal line; the two ends of the bypass pipeline are respectively communicated with the bottom of a crude oil pipeline in an openable and closable way, and the bypass pipeline is used for continuously leading out oil sealed in the crude oil pipeline; after the pressure of the sealed oil is released, the sealed low-viscosity oil flows out of the bypass pipeline under the action of self gravity when gas is introduced into the bypass pipeline; the invention also provides the sampling method based on the sampler. After the sampler and the sampling method are adopted, the under-pressure sampling, isothermal sampling and anti-shear sampling can be directly implemented under the premise of not influencing the normal conveying technology of the crude oil pipeline; furthermore, the sampler does not need to be driven by external force during sampling, and has the advantages of being little in sampling work load, less in production of waste oil, simple in structure and reliable in sealing.

Description

technical field [0001] The invention relates to the technical field of low-viscosity crude oil pipeline transportation equipment, in particular to a tubular sampler and a sampling method for realizing isothermal anti-shear sampling under pressure. Background technique [0002] The safe and economical transportation of low-viscosity crude oil often adopts the modification technology of adding pour point depressant. During the pipeline transportation of low-viscosity crude oil modified by adding a pour point depressant, it is necessary to regularly detect the changes in the rheological parameters of crude oil, so it is necessary to obtain oil samples from the pipeline in time to test the fluidity of crude oil. Crude oil modified by adding pour point depressant is easily affected by shearing action and temperature change. Therefore, the oil sample should be protected from shearing and temperature changes during sampling. [0003] At present, the existing crude oil samplers ar...

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Problems solved by technology

[0003] At present, the existing crude oil samplers are still unable to realize isothermal anti-shear sampling under pressure. Some samplers have a pressure difference inside and outside the pipeline during sampling, which cannot achieve the effect of eliminating shear; It needs to go through the circulation pump in the middle, so that the oil sample will be additionally sheared by the pump; although some samplers can prevent the influence of the shearing effect in the sampling process, they cannot fundamentally achieve isothermal sampling, and the oil discharged each time The same can only be treated as waste oil, which increases the workload and is not economical and environmentally friendly.

[0004] In addition, the existing structural design of the sampler also has defects. When the piston of the sampler goes down to discharge oil, a negative pressure will be generated in the emptied cavity, which not only makes it difficult for the piston to continue to move, but also easily causes friction between the piston and the inner wall of the sampler. Damaged seal rendering sampler useless

[0005] The above crude oil pipeline samplers only partially eliminated the sampling influence factors, and none of them met the requirements of isothermal anti-shear sampling under pressure. The structure and sealing are more complex

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