Hydrodynamic modeling as an instrument of selecting places of installing corrosion control units

UDK: 620.193:622.276.012.05

DOI: 10.24887/0028-2448-2020-8-100-102

Key words: corrosion monitoring, hydraulic modeling, flow regime, water accumulations, corrosion control unit, test specimen, multiphase flow, flow velocity

Authors: A.K. Sakhibgareev (RN- BashNIPIneft LLC, RF, Ufa), G.F. Shaykhulova (RN- BashNIPIneft LLC, RF, Ufa), T.A. Sataeva (RN- BashNIPIneft LLC, RF, Ufa), I.V. Kostitsyna (RN- BashNIPIneft LLC, RF, Ufa), P.V. Vinogradov (RN- BashNIPIneft LLC, RF, Ufa), I.M. Khusnullin (RN- BashNIPIneft LLC, RF, Ufa)

One of the reasons for failure of pipelines due to internal corrosion is an incorrect and untimely assessment of the degree of aggressiveness of the transported medium and, as a result, the selection and application of ineffective methods of corrosion protection. The main approach of corrosion monitoring to assess the corrosiveness of the environment is to introduce witness samples into the stream of the transported fluid, followed by monitoring their condition. A key step in organizing corrosion monitoring is to select a site for the installation of a test specimen. Existing methods for determining the installation locations of corrosion control nodes do not allow a comprehensive assessment of all influencing factors and take into account the particular operating conditions of the pipeline.
In the framework of the work, a new approach to the choice of the installation site of the corrosion control unit is proposed, including the following steps: 1) hydrodynamic modeling; 2) comparison of simulation results, actual data on failures and results of in-line diagnostics; 3) assessment of compliance of the recommended installation sites of the corrosion control unit with the requirements specified in state standards and regulatory documents of the company. This approach allows to take into account such factors as the flow rate of the gas-liquid mixture, the presence of stagnant zones of water accumulations and the flow regime, as a result of which the reliability and quality of the results of measurements of the corrosion rate during corrosion monitoring are increased. As a result of this work, it was revealed that hydrodynamic modeling under unsteady flow conditions is an effective tool for determining the sections of the pipeline that are most corrosive. The described approach is applicable both in the design of corrosion monitoring systems in new fields, and in optimizing the location of corrosion control unit already installed in the oil gathering system.
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