轻烃管网顺序输送的可行性研究

某油气田轻烃管网系统目前采用间歇混合输送的方式将原稳烃、浅冷烃和深冷烃混合输送至下游,存在管网压力偏高且波动大、管输轻烃质量差、外输泵能耗偏大、管网运行操作难度大等问题。为此,借鉴成品油管道顺序输送原理,综合考虑各站场产烃类型、产烃量、泵机组外输量、启泵时间需求、管道承压能力、输烃顺序、混烃界面等,计算得出轻烃管网的顺序输送方案,并提出了顺序输送时应遵循的原则:①所有站场采取集中注入方式进行轻烃注入作业;②应尽量避免各站场同时注入轻烃,采取相邻站场相继注入的方式,确保管道稳定运行;③各站场注入轻烃时应避开混烃段;④各站场注入轻烃管网时,必须满足各注入支线的管输能力及外输泵的工作流量要求。最后验证了该方案的水力可行性和经济性。结果表明:轻烃管网采取顺序输送方案,可节省泵站运行费用19.4万元/a,减少混烃量约133.3×104 m3/a,对现场减少管网压力波动和混烃损失量等具有重要意义。

A feasibility study of light hydrocarbon batching transportation through pipeline networks

A light hydrocarbon pipeline network system in an oilfield is now transporting three light hydrocarbons including deep cooling hydrocarbon, crude stabilization hydrocarbon, and shallow freezing hydrocarbon, in a mixed and intermittent way, which also brings about such problems as a rather high pressure and large pressure fluctuation, poor quality of light hydrocarbons in pipes, high energy consumption of efflux pumps, and bad operability. Therefore, based on the principle of product oil batching transportation via pipelines, a scheme of light hydrocarbon batching transportation via pipelines was put forward completely considering the amount and quality of hydrocarbon produced, initial time requirement and capacity of efflux pump groups, pipeline loading capacity, hydrocarbon feeding order, mixed hydrocarbon interface, and so on. Also, this proposed scheme was suggested to follow the following principles. First, light hydrocarbons at each station should be fed in the pipeline by the concentrated injection. Second, light hydrocarbons should be fed in succession at the neighboring stations instead of simultaneous injection thus to ensure the stable operation of pipelines. Third, the mixed hydrocarbon sections should be avoided through the light hydrocarbon injection at each station. Fourth, the capacity of each branch line and the work flow requirement of efflux pumps should be met when the light hydrocarbons are injected into the pipeline network at each station. Finally, the hydraulic and economic feasibility of this scheme were validated and the results showed that if the batch transportation plan has been adopted, the pumping power cost of the pipeline system can be reduced by 194 thousand yuan (RMB) per year and the mixed hydrocarbon volumes can be reduced by 1.33 million m³ per year. This study provides a valuable guidance for reducing the pipeline pressure fluctuations and mixed hydrocarbon losses.