特低渗透油藏压裂水平井产能影响因素分析

Influencing factor analysis of the productivity of fractured horizontal wells in ultra-low permeability reservoir

低渗透、特低渗透油藏具有启动压力梯度,且非均质性较为严重,裂缝参数对产能的影响与常规油藏显著不同。利用油藏数值模拟方法,分别研究了不同渗透率非均质性和不同启动压力梯度条件下,裂缝参数对压裂水平井产能的影响。结果表明,在低渗透、特低渗透油藏中,非均质性较弱的情况下,压裂水平井生产状况与均质油藏类似,在非均质性较强的情况下,应选择比均质油藏更多的裂缝条数和更大的裂缝半长进行生产;在启动压力梯度较大的情况下,应选择较多裂缝条数进行生产。

The low start-up pressure gradient and serious anisotropy have made the fact that effect of fracture parameters on productivity in fractured horizontal wells in ultra-low permeability reservoir is quite different from that in traditional reservoir. According to low permeability and ultra-low permeability reservoir characteristics, the influence of fracture parameters on fractured horizontal well productivity under different permeability heterogeneity and different pressure gradient conditions are analyzed respectively using numerical simulation method. The results show that in those kinds of reservoirs with weak heterogeneity, the fracturing horizontal well production conditions are similar to that in the case of homogeneous reservoir. On the other hand, when the reservoir heterogeneity is strong, it is suggested to select larger number of fractures and longer fracture half-length for production rather than in homogeneous reservoir; In the case of larger start-up pressure gradient, selecting larger number of fractures for production is proposed.