薄互层剩余油压裂挖潜工艺技术研究与应用

鄂尔多斯盆地某特低渗透油藏纵向上主要发育K1、K2两层,层内隔夹层发育。但经历20多年的开发后,受层间隔夹层和非均质性影响,前期采用以老裂缝充填和延伸为主的重复压裂工艺动用层间剩余油不明显,措施后含水率上升且单井增油量逐年下降。基于储层剩余油分布类型,剖析了储层纵向上剩余油分布界限和增产潜力,开展了储层纵向上地应力和储层物性变化研究,采用正交试验设计原理对比评价了影响重复压裂裂缝高控制的主要影响因素,提出了“水力喷射器+K344单底封”重复压裂工艺,并应用全三维压裂软件优化了储层关键参数。在某区特低渗透油藏现场应用10口井,试验井日产油是投产初期的近1.5倍。

Re-Fracturing Technology Research and Application for Remaining Oil in Thin-Interlayer Reservoirs

Two layers , including K1 and K2, are mainly developed for the low permeability reservoir in the Ordos Basin. The main layer of the K1 with interlayer growth contains 4 lower layers. However, with more than 20 years producing, re-fracturing for filling and extension the old hydraulic fracture couldn't extract remaining oil obviously because of the interlayers and heterogeneity, which cause the water cut rising and oil increment decreased year by year. Physical property boundary and stimulation evaluation about the residual oil have been evaluated on the analysis of the vertical distribution of remaining oil in reservoir. The main influence factors of the effect of repeated fracturing control by orthogonal design principle of are obtained after researching the alternation of stress and physical property. Fracturing technology of the "hydraulic jetting+K344 single packer" is put forward for the remaining oil. The field test of 10 wells after application of full 3 D fracturing software to optimize the key parameters of re fracturing proof that the oil per day is nearly 1.5 times as much as the initial production.