一种实现裂缝高导流能力的脉冲加砂压裂新方法

鄂尔多斯盆地致密油藏储量大、分布稳定,是长庆油田5 000万t上产、稳产的重要接替资源。该类油藏由于储层致密、物性差,前期改造效果差,常规压裂技术难以有效动用,急需开辟一条新途径进行油藏的有效改造。文中结合鄂尔多斯盆地致密砂岩油藏自身特征,阐述了"脉冲式加砂、纤维压裂液携砂及等间簇射孔"的一种新型压裂改造技术,在压裂裂缝中通过支撑剂的交替充填,形成稳定的流动通道网络,使裂缝具备较高的导流能力,从而达到提高单井产量的目的。通过3口直井的现场试验,与常规压裂井进行了对比分析。采用高导流能力的脉冲加砂压裂技术,压后初期裂缝导流能力提高14.1%,试油产量、投产产量、单位压差累计产油量和产能指数均比常规压裂井高1.1~1.4倍,取得了较好的现场应用效果。

A new method of pulse sand fracturing to achieve high conductivity of fracture

large reserves and stable distribution of tight oil reservoir in Ordos Basin are the important replacing resources for 50 million tons stable production of Changqing Oilfieht. For this kind of reservoir, due to dense and poor physical property, the modification effect at earlier stage is poor and the conventional fracturing technology is difficult to be effectively used. In order to open a new path for this kind of reservoir, this paper combined with the characteristics of tight sandstone oil reservoir in Ordos Basin and uses a new fracturing technology such as the mode of ＂pulse type sand, fiber fracturing fluid earrying sand, nmlti-cluster perforation with equal space＂. In the fracturing fracture, by alternating the proppant filling flow channel formed in the fracture network, the conductivity of fracture is high, achieving the purpose of improving single well production. The fieht test of three vertical wells shows that the conductivity of initial fracture increases by 14.1% after the pulse sand fracturing with high conductivity compared with conventional fracturing wells. The test oil production, the oil production put into production, cumulative oil production for unit pressure difference and productivity index are 1.1-1.4 times higher than conventional fracturing wells, obtaining the good field application effect.