致密砂岩油藏动态渗吸驱油效果影响因素及应用

Influencing factors of dynamic imbibition displacement effect in tight sandstone reservoir and application

渗吸驱油作为致密砂岩油藏高效开发的一项重要技术措施,近年来受到越来越多的关注。致密砂岩油藏渗吸驱油效果的影响因素较多,以鄂尔多斯盆地某区块致密砂岩储层为研究对象,通过岩心动态渗吸驱油实验,评价了渗吸液类型、渗吸液浓度、渗吸液注入量、驱替流速、反应时间以及岩心渗透率对储层岩心动态渗吸驱油效果的影响。结果表明:渗吸液中加入非离子表面活性剂HYS-3能够显著提高动态渗吸驱油效率;渗吸液中表面活性剂的浓度越高、渗吸液注入量越大、反应时间越长、岩心渗透率越高时,动态渗吸驱油效率越高;随着驱替流速的增大,岩心动态渗吸驱油效率呈现出先增大后减小的变化趋势;动态渗吸驱油实验最优参数为:驱替流速为0.2 mL/min,渗吸液为0.5%HYS-3,渗吸液注入量为1.0 PV,反应时间>48 h。矿场应用试验结果表明,实施注水吞吐动态渗吸驱油方案措施后,S油田5口井的日产油量是措施前的2倍多,含水率明显下降,增油效果显著。

As an important technical measure for efficient development of tight sandstone reservoirs,imbibition displacement has attracted more and more attention in recent years.There are many factors affecting the effect of imbibition displacement in tight sandstone reservoirs.Taking a tight sandstone reservoir in a block of Ordos Basin as the research object,the effects of the types,concentration and injection volume of imbibition fluid,displacement velocity,reaction time and core permeability on dynamic imbibition displacement were evaluated by rock core dynamic imbibition displacement experiment.The results show that adding non-ionic surfactant HYS-3 into the infiltration fluid can significantly improve the dynamic imbibition displacement efficiency.The higher the concentration of surfactant in the infiltration fluid,the larger the injection volume of the infiltration fluid,the longer the reaction time and the larger the core permeability,the higher the dynamic imbibition displacement efficiency.With the increase of displacement flow rate,the dynamic imbibition displacement efficiency of the core increased first and then decreased.The optimum parameters of dynamic imbibition displacement experiment are:displacement velocity is 0.2 m L/min,concentration of imbibition fluid is 0.5%HYS-3,injection volume of imbibition fluid is 1.0 PV,reaction time is more than 48 hours.The field application test results show that the daily oil production of 5 wells in S oilfield is more than twice that before the implementation of the dynamic imbibition displacement measures of water injection huff and puff,the water cut is obviously reduced,and the effect of oil increase is remarkable.