超低渗透率致密油藏烃气驱参数优化

Optimization of Hydrocarbon Gas Flooding Parameters in Ultra-Low Permeability Tight Reservoirs

超低渗透率致密储层通过实施水平井+体积压裂技术能够有效提高单井产量,但仅依靠天然开采,单井产量下降较快,需探索新方式来提高致密油藏采收率。以X区块超低渗透率致密油藏为研究目标,结合现场实际情况,建立1注2采机理模型,研究注入时机、注入气量、注气速度和日产油量对增油效果的影响。结果表明:注入时机与采收率呈负相关线性函数关系,注入时机越早越有利于提高采收率;过低注入气量、注气速度不能有效补充地层能量,过高注入气量、注气速度会导致注入压力高、难注入等问题;过低日产油量不利于油藏的经济开发,过高日产油量导致驱油效率降低。通过对油藏进行烃气驱注采参数优化得到最优开发方案,为其他超低渗透率致密油藏高效开发提供理论指导和借鉴。

The horizontal well and volume fracturing technology can effectively increase the production of a single well in ultra-low permeability tight reservoirs.However,the production of a single well decreases rapidly by relying solely on natural energy production.Therefore,it is urgent to explore new ways to supplement energy to improve the recovery efficiency of tight reservoirs.In this paper,the ultra-low permeability tight oil reservoir in block X is taken as the research objective,and combined with the actual situation of the field,the mechanism model of one injection and two production was established.The effects of injection timing,injection gas volume,gas injection speed and daily oil production on the oil increase effect were studied.The results show that the injection timing is negatively correlated with the recovery factor,and the earlier the injection timing,the better the recovery factor.Too low injection gas and gas injection speed can not effectively supplement formation energy,but too high injection gas and gas injection speed will lead to high injection pressure,difficult for injection and other problems.Too low daily oil production is not conducive to the economic development of the reservoir,and too high daily oil production will reduce the oil displacement efficiency.An optimal development scheme is obtained by optimizing hydrocarbon gas flooding parameters,which provides theoretical guidance and reference for the efficient development of other similar ultra-low permeability tight reservoirs.