低渗透率油藏压裂水平井产能影响因素

通过科学的抽象,建立了大量的非均质地质模型,以油藏数值模拟为手段,系统地研究了压裂水平井在低渗透率油藏中的开发动态,建立了压裂水平井累积产量增产倍数图版.所考虑的影响因素包括人工裂缝的方向、K_v/K_h、裂缝条数、裂缝长度、裂缝导流能力、储层渗透率、裂缝间距和非均匀裂缝长度等.研究表明：压裂水平井裂缝条数以3条相对较优;最佳裂缝长度与裂缝导流能力和储层渗透率有关;对于特定的油藏,存在相对较优的裂缝导流能力值;两条最外边裂缝的间距对压裂水平井产能有一定的影响;由于压裂水平井段上不同位置裂缝的产量贡献值有差别,建议加大中间裂缝的长度或导流能力,以达到裂缝间产量贡献值的均衡.在对裂缝条数、长度和导流能力研究的基础上,建立了增产倍数图版.

A STUDY ON FACTORS AFFECTING THE PERFORMANCE OF HYDRAULICALY FRACTURED HORIZONTAL WELL IN LOW PERMEABILITY RESERVOIRS

Over 200 heterogeneous geological models were established through reasonable ion. By means of reservoir numerical simulation, the paper had systematically studied the factors affecting the performance of fractured horizontal well, and Qfrac/Qunfrac template was constructed. The factors taken into account include fracture direction corresponding to the direction of wellbore, Kv/Kh, number of fractures, length of fractures, fracture conductivity, distance between the outmost fractures and length of uneven fractures. The study shows that the optimal number of fractures might be 3, the optimal length of fracture is related to fracture conductivity and reservoir permeability and for a specific reservoir, there does exist an optimal fracture conductivity. Distance between the outmost fractures influences the productivity of fractured horizontal well. The productivity of fractures is related to the positions of fractures on fractured horizontal wellbore. So, it is suggested that the length or conductivity of middle fracture be increased to achieve the productivity balance of di fferent fractures. Finally, Qfrac/Qunfrac template was established based on the studies of number of fractures, length of fracture and fracture conductivity.