Numerical Simulation Analysis of Filling and Decommissioning Oil and Gas Pipelines

Oil pipeline transportation is the primary mode of transporting petroleum products, and its safety and environmental concerns have garnered significant attention. The decommissioning of oil and gas pipelines plays a crucial role in the life cycle management of these pipelines. Worldwide, addressing the aging issue of oil and gas pipelines has become an urgent matter that requires immediate resolution. In order to effectively abandon underground oil and gas pipelines while ensuring sustainable development, this study conducts numerical simulation analysis on Controlled Low Strength Material (CLSM) used for filling and decommissioning purposes. In this paper, CLSM slurry, a new material with low strength, high fluidity, and low bleeding rate, is regarded as Bingham fluid. The changes of initial yield stress and plastic viscosity of the slurry with time are studied by rheological equations, and the rheological equations of CLSM slurry are proposed. In this paper, the flow dynamics characteristics of CLSM slurry in a straight pipe are studied by numerical simulation, and the flow velocity field changes of slurry in a straight pipe at different time points, different flows, and different diameters are analyzed. Additionally, a numerical calculation model is established to simulate the flow dynamic characteristics of CLSM slurry pipelines, aiming to provide reliable theoretical and technical support for developing a comprehensive and efficient CLSM filling technique within the context of decommissioned oil and gas pipeline systems.