A Study To Improve The Cement Slurry Quality And High Return Of Wuqi Oilfield

Conventional density cement slurry dropout in Wuqi oil field lead to the problem of top of cement. In order to solve the problem, a lot o f work will be done, including consult related data at home and abroad, formation characterization and bearing compress capacity, dropout reason. And then technical idea and solution will be offered in paper through comprehensive analysis. The key is to decrease the pressure to cement slurry column, there are two ways to choose. One is that operator uses low density slurry. The other is that operator practices two-scale cementing technique. The point is to study the technique of low density slurry. In the process of this, what will matter is to solve the stability of low density slurry system and the strength of low density cement.Through test indoors, the decrease of ash, floating bead and their combination will be studied so that according formula will be known and application of slurry cement to low density(1.45g/cm3) about on-site ash. In the paper, there are two wells as examples(5-265 well,41-136 well). At the same time, there are two wells(49-29 well, 5-287well)as the practice of two-scale cementing. Eventually, the shortcoming to top of cement is done. study will improve cementing quality and prolong time of well using.The main research results:(1) the problem of stability to low density slurry has been done by study of the focus. Ash, as a composition of low density slurry, is wide supply and economical. Same, low-density slurry additive ZW are screened and determined.(2) the effect of two-scale cementing test in Wuqi oil field is rather obvious, the position of hoop design is very scientific.(3) the study shows that the lowest density value of ash is 1.45g/cm3. In engineering application, if there still is dropout for low density slurry, the lighter will be chosen(for example: floating bead).(4) in a bid to reduce pressure during the construction and avoid leakage of formation, some measures are taken, such as displacement control and turbulent water slurry, plug flow replacement technology. The effect is very obvious.