新疆吉木萨尔页岩油藏压裂水平井压裂簇数优化研究

Study on optimization of fracture cluster number of multiple fractured horizontal well in jimsar shale oil reservoir in xinjiang oilfield

页岩油藏原始渗透率极低,自然条件下无经济产能,实践表明大型水力压裂是高效开发页岩油藏的最有效手段.然而,目前鲜有关于页岩油藏压裂水平井裂缝簇数优化研究的报道.针对这一问题,利用不稳定渗流理论建立了多段压裂水平井多井数值模型,在储量动用充分的原则,提出了一套页岩油藏多段压裂水平井裂缝簇数优化方法,并进行了实例应用分析.结果发现,当昌吉油田页岩油藏多段压裂水平井裂缝簇数大于80条,累计产油量的增长趋势趋于平缓,可确定其合理的裂缝簇数为70~80,簇间距范围在15~20 m左右.由最优裂缝簇数为75的理论模型进行产量预测,计算发现昌吉油田页岩油藏压裂水平井的累计产油量为25150 m 3,此工作可为新疆昌吉油田页岩油藏的压裂水平井裂缝簇数设计提供理论参考.

Shale reservoirs have very low original permeability and no economic productivity under natural conditions.Practice shows that large hydraulic fracturing is the most effective means to develop shale reservoirs efficiently.However,there are few reports on the optimization of fracture cluster number in fractured horizontal wells in shale reservoirs.In view of this problem,the multi-well numerical model of multi-stage fractured horizontal wells is established by using the unstable seepage theory,and a set of optimization method of fracture cluster number of multi-stage fractured horizontal wells in shale reservoir is put forward on the principle of full utilization of reserves.The results show that when the number of fracture clusters in multi-stage fractured horizontal wells in Changji oilfield is more than 80,the cumulative increase trend of oil production tends to be flat.It can be determined that the reasonable cluster spacing range is about 15~20 m,and the number of fracture clusters is 70~80.According to the theoretical model with an optimal number of fracture clusters of 75,the cumulative oil production of fractured horizontal wells in shale reservoirs in Changji oilfield was calculated and found to be 25150 m 3.This work can provide theoretical reference for the design of fracture clusters in fractured horizontal wells in shale reservoirs in Changji oilfield,Xinjiang.