高含水原油干线管道低温集输理论基础及现场试验
吕杨1，张瀚文2，刘罗茜2，张富强3

1.国家管网集团油气调控中心;2.国家管网集团科学技术研究总院分公司;3.中国石油工程项目管理公司天津设计院

高含水原油;低温集输;粘壁现象;粘壁温度;工程应用

Theoretical basis and field experiment of low-temperature gathering and transportation for high water-cut crude trunk pipeline
LYU Yang1，ZHANG Hanwen2，LIU Luoqian2，ZHANG Fuqiang3

1.PipeChina Oil & Gas Control Center;2.PipeChina Institute of Science and Technology;3.Tianjin Design Institute of CNPC Project Management Company

high water-cut crude oil, low-temperature gathering and transportation, wall-sticking occurrence, wall-sticking occurrence temperature, engineering application

DOI: 10.6047/j.issn.1000-8241.2024.08.008

备注

【目的】目前中国大部分内陆油田已进入高含水开采阶段，含水率达90％以上甚至有个别区块的含水率大于95％，导致油田地面集输系统的加热能耗较高。为解决这一问题，部分高含水油田开展了高含水原油低温集输的现场试验，但仍存在“能否降温、降到多少温度以及是否发生粘壁现象”的工程技术问题。【方法】利用室内实验与数值模拟相结合的方法对高含水原油低温集输粘壁温度（最低进站温度）进行了测试与模拟，得到了输送温度、析蜡特性对粘壁现象的影响规律，发现了析蜡点、析蜡高峰与粘壁温度的相关性。利用Pipesim软件对集输管道的水力热力特性进行了模拟计算，探究了不同进站温度下管道沿线的温度与压降。【结果】集输干线实现了外输温度从原本的55℃降至39℃的低温集输，在外输温度降低16℃的工况下，低温集输管道可安全运行。同时热力中转站W5的加热炉单日可节省天然气2032m3，取得了良好的经济效益，并在此基础上制定了高含水原油的低温集输方案与流动保障措施。【结论】研究成果可保障集输管道在降温过程中的安全运行与风险预测预警，未来可通过引入修正系数或优化水力热力计算模型算法来提升高含水原油地面集输管网的水力热力计算精度。该集输干线低温集输现场试验可为高含水油田开展低温集输工作提供经验参考与工程应用实例。（图 11，表2，参[23]）
[Objective] Most inland oil fields in China are currently in the high water-cut production stage, with a water cut of generally above 90% and even exceeding 95% in some blocks. This situation leads to increased heating energy consumption for the surface gathering and transportation systems of these oil fields. In an effort to address this challenge, field experiments on low-temperature gathering and transportation of high water-cut crude oil have been conducted in some high water-cut oil fields. Nevertheless, some engineering technical uncertainties persist, such as the feasibility of temperature reduction, the extent to which temperature can be decreased, and the potential wall-sticking occurrence. [Methods] The wall-sticking occurrence temperature (minimum inlet temperature) for low-temperature gathering and transportation of high water-cut crude oil pipelines was investigated through laboratory experiments and numerical simulations. The results revealed the impacts of transportation temperatures and wax precipitation characteristics on wall-sticking occurrence, leading to the establishment of correlations between wax precipitation points/peaks and wall-sticking occurrence temperatures. Furthermore, the hydraulic and thermal properties of the gathering and transportation pipelines were simulated using Pipesim software to assess temperature profiles and pressure drops along the pipelines with different inlet temperatures. [Results] The trunk pipeline operated safely for oil gathering and transportation, with the outlet temperature reduced from 55 ℃ to 39 ℃ (a decrease of 16 ℃). Additionally, the heating furnace at the W5 heating transfer station realized a natural gas saving of 2 032 m3 per day, showcasing significant economic advantages. Building upon the research results, a low-temperature gathering and transportation solution for high water-cut crude oil and flow assurance measures were developed. [Conclusion] The research findings can be applied to ensure safe operations and facilitate risk prediction and early warning for gathering and transportation pipelines undergoing temperature reduction. Future studies may incorporate correction coefficients or optimize algorithms within the hydraulic and thermal computational model to enhance the precision of hydraulic and thermal calculations for surface gathering and transportation pipeline networks handling high water-cut crude oil. This field experiment involving the low-temperature gathering and transportation trunk pipeline serves as a valuable reference and practical example for implementing low-temperature gathering and transportation in high water-cut oil fields. (11 Figures, 2 Tables, 23 References)
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