常规稠油边水油藏氮气泡沫抑制水侵试验

Experiment on nitrogen foam anti-edge water invasion in normal heavy oil reservoir with edge water

稠油开发中油藏边水的存在造成吞吐井迅速水淹,产量急剧降低。根据河南油田边水稠油油藏的特点,建立能够模拟油藏边水的蒸汽吞吐物理模拟试验装置,在分析泡沫剂和稠油性能基础上对氮气泡沫抑制边水的影响因素及应用条件进行研究。结果表明:氮气泡沫抑制边水技术适用于原油黏度较低、边水能量适中、非均质性较强的油藏,且在强水淹时实施能取得较好的抑制边水效果,应先注入N2段塞,再注N2泡沫段塞,然后N2与蒸汽混注;试验期累积增油9691 t,平均含水率下降9.2%,单井油气比提高0.11,投入产出比为1∶1.72,控水增油效果明显,达到了抑制边水的目的。

In heavy oil reservoir with edge water, the production well is flooded very soon, and the oil production decreases sharply. An experimental device simulating edge water was designed according to the feature of Henan heavy oil reservoir with edge water. The influence factors and application conditions of nitrogen foam anti-edge water invasion technique were researched by analyzing performance of Henan foam agent and crude oil. The results show that the antiedge water invasion technique is fit for the heterogeneous reservoir with a moderate energy edge water and low viscosity heavy oil, and a better blocking result will be gotten at the time of serious flooding. The optimum injection mode is N2 plug firstly, followed by nitrogen foam plug, and then the plug of N2 and steam mixture. During pilot tests, 9691 t extra crude oil is produced, the average water cut decreased by 9.2% , and the oil and gas ratio increased by 0.11. The input-output ratio is 1 ： 1.72. The water cut decreases and oil production increases significantly, so the target of edge water inhibition is achieved.