A Pre-liquid Study For Oil-based Drilling Fluid Cementing

In view of the problem is difficult to guarantee the cementing quality under the oil-base drilling fluid, In order to achieve the purpose of improving cementing quality, cementing preflush fluid and cement slurry system formula have been studied in this paper. On the basis of a large number of literature, by means of experimental methods, through analysis the oil-base drilling fluid affect the cementing quality of second interface cementation, then optimizing the flushing fluid CX-1 and spacer GL-1, developed the anti-pollution agent Anti-P, developed cementing preflush fluid and cement slurry system formula and formed multi-level configuration technology for the high density preflush fluid.The main research work and achievements are as follows:(1)Through a large number of literature, research on the cementing of preflush fluid and cement slurry system at home and abroad now. And obtained the research idea of this paper. Start from the effects of the oil-base drilling fluid on interface cementation quality, optimizing the cementing preflush fluid and cement slurry system formula, forming the cementing techniques under the oil-base drilling fluid.(2)Using the method of artificial core experiment evaluation cementing cementation strength under the oil-base drilling fluid, The experimental results that the first and second interface cementation strength of the cementing cement ring fell sharply, The most serious influence is the second interface. The reason is the oil-base drilling fluid itself characteristics and chemical reagent for the oil-based drilling fluid.(3)Respectively research on the flushing fluid and spacer fluid formula.Choose the clear agent RJ-4 as the main emulsifying agent of the flushing fluid, The main agent formula CX-1 is:30% RJ-4+60%B-2+10% C. Choose the isolation agent WH-2 as the aggravate suspending agent of the spacer fluid, The main agent formula GL-1 is:Water+4%WH-2+0.3% fluid loss agent CPS2000+15% Oil cleaning agent CX-1+Weighting material.(4)Experimental evaluation the specific performance of CX-1 and GL-1. The cementing preflush has good performance and realize the effective displacement of oil-base drilling fluid.(5)Experiment developed the Anti-P, carried out the pollution compared experiment under different pollution agent added amount, the slurry still has strong stability by adding 1% Anti-P, which contaminated with traces of oil-base drilling fluid. It ensured the quality of well cementation.(6)High density preflush fluid preparation process was studied, Formed a multi-level preparation process, guarantee the preflush performance is the same of laboratory experiments and field configuration.The technology has been applied to field practice, and achieved good application effect.