环道内胶凝原油停输再启动触变模型参数求解

Solution of thixotropic model parameters during shutdown and restart of gelled crude oil in loop

触变性是衡量含蜡原油低温流动性的重要指标,对胶凝原油管道停输再启动过程的水力特性及安全性至关重要。现有触变模型参数求解仅考虑了启动后流量恢复阶段的触变数据,忽略了启动初始时刻管道内胶凝原油已经发生触变的事实。借助管流试验装置,设计控制流量的启动试验,基于启动初始充装阶段环道沿线压力数据,提出了一种获取该阶段触变数据的方法。以环道停输再启动两阶段的触变数据为基础,计算4参数双曲触变模型相关参数,得到描述胶凝触变特性的数学模型。与传统求解环道内胶凝原油触变模型参数的方法相比,考虑启动初始充装阶段求解的触变模型更能反映环道内胶凝原油真实的触变特性。

Thixotropy,an important index to measure the low-temperature fluidity of waxy crude oil,is crucial to the hydraulic characteristics and safety of gelled crude oil during pipeline shutdown and restart.In the existing process of solving the parameter of the thixotropic model,the thixotropic data in the flow recovery stage after start has been taken into consideration,but the fact that the gelled crude oil in pipeline is thixotropic at the initial moment of startup,has been ignored.The startup test for controlling the flow was designed via the loop flow experimental device,and the method for acquiring thixotropic data in the initial flow filling stage was proposed based on the pressure data along the loop at the startup stage.Based on the thixotropic data of the two stages of loop shutdown and restart,the related parameters of the 4-parameter hyperbolic thixotropic model were calculated,and the mathematical model describing the thixotropic characteristics of gelled crude oil was obtained.Compared with the traditional method for calculating the parameters of the thixotropic model of gelled crude oil in the loop,the solved thixotropic model,which has taken the initial filling stage into consideration,is able to better reflect the real thixotropic characteristics of gelled crude oil in the loop.