Polycyclic Intermittent Steam Injection Technology For SAGD Wells

Using SAGD production practice at heavy oil reservoir, it needs to take intermittent steam injection according to reservoir condition and producing effectiveness. However, the problem that reinjection after shutting down seals bad can not be resolved without retubing.On the basis of heavy oil thermal recovery, we start to design and research metal-clad seals of Y441 packer & seal compensating device, seal compensating method of compensating pipe and resilience prevention expansion structure of long term sealer. We have succeeded in developing intermittent steam injection technology for SAGD wells and solving the problem that secondary sealing after temperature release and pressure release. The technology is able to fill intermittent steam injection'need in process of field application. The high temperature steam injection string-temperature resistant: 350℃; pressure resistant: 17MPa; intermittent circle: 1 month; thermal loss decrease by: 5-10%. At present, 40 wells'field application have been finished. We can see that effectiveness of thermally insulating the borehole has been significantly improved. The success ratio achieves 100%.At present, direct at SAGD steam injection technology, the intermittent steam injection string which developed by Drilling & of Liaohe Oilfield is able to comprehensive enhance steam drive string's sealing property & unseating property, borehole's insulating property and injection sealing property. The technology provide strong support for long-term continuously steam injection of SAGD wells and achieve international leading standard.