Design Of Low Density Cement Slurries System Of Thermal Well

The effective exploitation of heavy oil reservoir of the shallow layer is playing greatsignificant in producting stabilization of a oilfield. Because this block reservoir burial depth isshallow,formation pressure is low, it is suitable for thermal recovery development.so cementsheath have to withstand high temperature up to300℃. In casing and cement sheath, it willproduce high thermal stress,it will make cement strength recession,cement sheath integritydestruction,causing casing damaged and so on. These problems will bring a lot of bad resullts,such as cementing failure, isolation of individual zones failure,production of oil wellsabnormal seriously,this series of results will bring huge economic losses of oilfield. For theabove reasons,selecting and designing of slurry, we must consider use low density cementslurries system which can effectively inhibit the effect of cement strength high temperaturerecession.In this paper, we make oilfield formation conditions and the shallow heavy oil wellconditions as the research background, on the basis of the analysis of high temperaturecement paste strength recession mechanism of action,and to explore the technical measuresand methods of protection of cement paste temperature strength, we have studied a series ofissues,such as cement slurry system design, thermal recovery slurry injection for the rheologycomputer software design. We make a reasonable choice of cemeal admixture and additive forcement and carry out a large number of experimental detections,and then we optimal a lowdensity cement slurries system which can resistant to high temperature strength recession.Analysised some issues about cementing,established of the calculation model,developed aslurry injection analysis and calculation software for the process flow rheology. This soft canselected slurry and other liquid rheological model automatically and calculat parameter, thedesign for the flow rate of cementing and displacing,calculation for the flow simulation,forthe balance of flow of the process pressure. Achieve the cementing process in slurry injectionfor mobile dynamic process and related parameters change in visual simulation. Throughtesting and verifying in several wells on site, the simulation and measurement results arealmost identical,thus the software provides a powerful supporting tool and means for makingcementing design and guiding the cementing operation.It provide technical support indesigning and constructing thermal well cementing, improving cementing quality,protectingthe thermal process carrying out smoothly, protecting oil well production life.