提高重复压裂井压裂效率技术研究及应用

Research on improving the fracturing efficiency of refracturing wells and its application

水力压裂技术是低渗透油气藏改造的主要措施,但经过水力压裂后的油气井,生产过程中由于压裂裂缝的闭合、油井产出过程中产出物对裂缝的堵塞、以及压裂后其他作业对近井地带的污染等原因,造成产量下降,甚至低于压裂前的水平。为了最大限度地改造剩余油富集区,最有效的措施是开展重复转向压裂,使新裂缝与原裂缝发生一定角度的偏转,以提高油藏采出程度。阐述了转向压裂技术原理,通过优化压裂液体系,优选支撑剂类型,并开展了34口井现场试验,取得了很好的压裂效果。得出转向压裂是江苏油田低渗透油藏高含水期一种新的重复压裂技术。

Hydraulic fracturing is one of major simulation measures for low - permeability reservoirs. But after hydro- fracturing operation, the production rate of oil or gas wells would decrease gradually, even below the former because of the fracture closure, proppant - pack, and damage near wellbore, which was caused by other oil well operations after frac. The best way to solve this problem is to carry out replication turnaround fracturing to create some new turnaround fractures, and to the max stimulate the remaining oil and enhance oil recovery. The principle of turnaround fracturing technology was ex- pounded. On the basis of fracturing fluid optimization and proppant type selection,field tests were carried out in 34 wells, which have obtained good results. It is approved that the turnaround fracturing is a new refracturing technology for low - permeability reservoirs with high water cut in Jiangsu Oilfield.