超深稠油自喷井掺稀深度优化研究

超深稠油井在生产初期地层压力高、原油黏度大,通过开式反掺稀油降黏工艺能使油井自喷生产,该工艺存在一个合理的掺稀深度。结合开式反掺稀油降黏工艺的实际情况,通过分段建立井筒温度场模型,筛选黏度计算模型和井筒压降计算模型,综合考虑掺稀深度对启动压力、流动困难点、井筒温度场、压力场等因素的影响,得到一种掺稀深度优化设计方法,利用该方法对西部油田A井进行掺稀深度优化,得到了最优掺稀深度。

The study of diluting depth for heavy oil in ultra-deep flowing well

In the early stage of oilfield development, the reservoir has a high formation pressure and the viscosity of oil is very high. So it is necessary to take some methods to decrease the viscosity of the heavy oil. It is well known that doping thin oil is a good method to decrease the viscosity. However determine a reasonable incorporation depth is very important in actual application. In order to get a good method to determine the reasonable incorporation depth, this paper establishes the pressure models and temperature models of wellbore flow. Meanwhile, the adequate method which is used to calculate the viscosity was chosen. Also the optimal design of incorporation depth takes into account of some factors, which is sensitive to the change of incorporation depth, such as threshold pressure, the temperature and pressure of wellbore, in the spot where has great flow resistance, and so on. What is more, this paper has put this method into practice. According to actual data of A well, which is located in west reservoir, it is convenience to give the best incorporation depth by this optimal design method.