Method for determining drag-reduction effect of pipelines on multiphase flow

Abstract

The invention discloses a method for determining the drag-reduction effect of pipelines on multiphase flow, in particular for evaluating the drag-reduction effect of a drag-reduction technique on multiphase flow by using the frictional strength and relative change rate of multiphase flow as the basic determination parameters. The method of the invention is applicable to the determination of drag-reduction effect of various pipeline forms, such as horizontal pipes, inclined pipes, vertical pipes and the like on various flow patterns, such as bubble flow, slug flow, annular flow, stratified flow and the like. The method comprises the following determination procedures: verifying the flow rate, temperature, pressure and other specific parameters under the working conditions of multiphase flows on the premise that the pipeline form is determined, and judging the flow pattern of the multiphase flow according to the flow pattern map of the multiphase flow corresponding to the pipeline form;determining the non-drag-reduction fictional strength; then, keeping the parameters under the working conditions of the multiphase flow unchanged and determining the drag-reduction frictional strength by using the drag-reduction technique; and calculating the drag-reduction rate from the relative change rate of the frictional strengths, thus judging the drag-reduction effect of the multiphase flow.

Description

technical field [0001] The invention is a method for measuring the drag reduction effect of multiphase flow for different pipeline forms such as horizontal pipes, inclined pipes and vertical pipes. Background technique [0002] Multiphase flow drag reduction technology has a wide range of connotations, including polymer drag reduction, surfactant drag reduction, bubble drag reduction, water ring drag reduction, fiber drag reduction and other methods. The research on drag reduction technology can be traced back to the 1930s. For the drag reduction of single-phase fluid flow, not only considerable research has been done at home and abroad, but also some patented technologies have been formed. However, the research on drag reduction of multiphase flow Also relatively few, lack of corresponding patented technology. With the exploitation of offshore oil and gas resources and land marginal oil and gas resources, there are more and more multiphase flow production pipelines, and hi...

AI Technical Summary

Problems solved by technology

However, for heterogeneous multiphase flow in inclined pipes and vertical pipes, including stratified flow, slug flow, and annular flow in inclined pipes, and flow patterns such as slug flow, block flow, and annular flow in vertical pipes, The energy consumption caused by the friction between the fluid and the wall and the friction between the various phases is not all reflected in the frictional pressure drop of the pipeline. In these cases, it is inaccurate to use the existing measurement method to evaluate the drag reduction effect of multiphase flow

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