Research On Supporting Technology Of SAGD Intermittent Steam Injection

In the SAGD(steam-assisted gravity drainage) pilot site Du 84 block in Liaohe oilfield,thirteen well groups of Guantao reservoir have transfered to production stage of SAGD and another four well groups of Xingâ…¥reservoir series are in the steam stimulation and preheating stage at present. SAGD application in heavy oil reservoirs need to adjust single well input rate according to downhole status and production effect, and sometimes intermittent steam flooding is necessary. Therefore bottom hole pressure and temperature should be dynamically monitored and known so as to provide reference for adjusting steam injection and taking related steps. The development model and characteristics of SAGD technology applied in heavy oil reservoirs determines that its development effect is closely related to steam dryness. Only when the long high-temperature sealing assembly of its allied tool could enhance repeated sealing property, inoxidizability and reduce the heat loss then the allied steam injection string can meet the intermittent steam injection requirement. Therefore, this paper carried out research in two areas: (1) We have carried on the research about dynamic monitoring system of pressure and temperature. By analyzing the technical configuration and feasibility of the monitoring system the fallowing researches are conducted: research on thermocouples connection technology inside capillary tube, research on multiple capillary tube connection technology within the coiled tubing, research and design on small-diameter high temperature transduction cylinder device and so on. With the researches mentioned above, the multipoint temperature and pressure monitoring system is developed and the localization of this technology is totally achieved, which meets the production requirement, solves dynamic monitoring problem of the pressure and temperature in SAGD wells and provides the basis for timely steam injection adjustment. (2) Aiming at the difficult problem of Long-term effective sealing during intermittent steam injection process, researches on sealing assembly of Y441-152 steam-drive packer, metal packing sealing assembly, steam-drive telescopic pipe sealing assembly, steam-drive collar sealing device etc and intermittent steam injection string are conducted. Through a great of laboratory experiments and field applications, this new type of sealing assemble and the intermittent steam injection string enhance the overall strength and corrosion resistance, and further improve the sealing and heat insulation performance after setting, meet the secondary sealing requirements of intermittent steam injection, provide allied technology assurance for intermittent steam injection in exploiting ultra heavy oil through SAGD.