低渗油藏单井N_2吞吐效果影响因素实验研究  

Experiment research on influence factors of N_2 huff-puff for single well in low permeability reservoir

作　　者：孙永鹏[1] 杨胜来[1] 徐君[2] 肖林鹏[2] 卢军凯[1] 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [2]吐哈油田分公司,新疆哈密839009

出　　处：《断块油气田》2011年第1期83-86,共4页Fault-Block Oil & Gas Field

摘　　要：三塘湖油田储层渗透率低,原油黏度高,单井产量低,注水难。为了提高单井产能,考虑注入气体,但是常规气驱用气量大,且易出现腐蚀、指进等问题,故考虑采用N2吞吐采油。分析了N2吞吐提高采收率机理,设计出储层条件下的单井模拟实验,研究单井N2吞吐采油的生产规律及其影响因素。使用三塘湖油田含气原油在长岩心物理模型上进行了一系列室内模拟实验,研究了周期注入量、井底流压和降压方式对周期采出程度的影响,得到了吞吐周期-周期采出程度关系曲线和注采关系曲线。发现周期注入量和井底流压是影响周期采出程度的重要因素,提高N2周期注入量、降低井底流压可以提高采出程度,二级降压可以得到更好的经济效果,且吞吐周期不应超过3个。该研究对油田N2吞吐方案设计有一定的参考价值。The reservoir permeability in Santanghu Oilfield is very low, the flow seepage resistance is big, the viscosity of crude oil is very high, the single well production rate is very low and it is very difficult for waterflooding development. In order to improve the single well productivity, the gas injection is considered. However, the gas consumption is really huge under the condition of the ordinary gas flooding and it is easy to come with the problems of corrosion and fingering. So the nitrogen huff-puff is considered to increase oil recovery. This paper analyzed the principle for nitrogen huff-puff to increase oil recovery, designed the single well simulation experiments under the reservoir condition and studied the production disciplines and influence factors of single well. By using the crude oil from Santanghu Oilfield, we conducted series of simulation tests to study the influence of periodical injection, downhole pressure and multistage depressurization on periodical recovery degree on the long core physical model, acquiring the curves of huff-puff period-periodical recovery degree and injection-production relationship. The results show that the periodical injection and downhole pressure are the most important factors on the periodical recovery degree. Increasing the periodical nitrogen injection rate and decreasing the downhole pressure can improve the oil recovery degree. Two-stage depressurization can get better economic gain and the number of huff-puff periods can not exceed 3. This research is valuable for the program design of nitrogen huff-puff.

关 键 词：N2吞吐 高黏原油 低渗储层 实验 

分 类 号：TE348[石油与天然气工程—油气田开发工程]