深水高凝油井井筒流动安全保障计算分析

Calculation and Analysis of Wellbore Flow Assurance in High Pour Point Oil Wells

深水油气田生产过程中,油气井的启动关井等瞬态工况条件下,产量及井筒温压场变化大,带来与之相关流动安全保障问题。本文以南海某水下井口开发高凝油田为例,采用多相流瞬态计算软件,系统分析在油井短期关井、热启动工况条件下井筒温压及产量变化,确定油井非操作时间,在此基础上,分别考虑正常工况以及极端工况条件下的挤柴油压井防凝措施,计算挤柴油压井防凝所需柴油用量、挤注时间、挤注速率、挤注压力等关键参数,保障井筒流动安全。

In the production process of deep-water oil and gas fields,the production and wellbore temperature and pressure field change greatly under the transient conditions such as start-up and shut-in,which brings about the related flow assurance problems.Taking an underwater wellhead high pour point oilfield in South China Sea as an example,this paper uses transient calculation method to systematically analyze the changes of wellbore temperature,pressure and production under short-term shut-in and start-up conditions.On this basis,the non-operation of oil wells is determined,and the measure of squeezing diesel oil into the wellbore is proposed.Furthermore,the key parameters,such as the amount of diesel oil,injection time,injection rate and injection pressure,are calculated under normal and extreme conditions to ensure the wellbore flow safety respectively.