Low Density Solid Control Of Liaohe Oilfield Drilling Fluid

At present,most drilling fluid engineers use low density solid phase controlling degree of drilling fluid as an important index to evaluate drilling fluid properties.Low density solid phase control within reasonable limits plays a key role in the improvement of mechanical drilling speed and wellbore stability,and plays a protective role for reducing costs and increasing effectiveness in the whole Liaohe oilfield.Aiming at the difficult problem of low density solid phase control of drilling fluid in Liaohe oilfield,the paper analyzes the reasons of higher low density solid phase content,through the technical measures such as improving the efficiency of solid control equipment,adjusting drilling fluid composition,optimizing drilling fluid properties,which can control the low density solid phase,and put forward specific countermeasures for the problem of caused in the low density solid phase control process of drilling fluid,borehole stability,drilling fluid properties fluctuation,and well leakage.The results show that the drilling speed is increased obviously and achieve good effect by controlling strictly low density solid phase of drilling fluid.Optimizing drilling fluid system according to different stratum and lithology.The traditional organosilicon drilling fluid system is replaced by polymer non-dispersing drilling fluid system,polymer-sulfonate-organosilicon drilling fluid system and polymer-ligno-sulf-onate drilling fluid system,which control the rise of low density solid phase from the source.The low density solid phase is cleared with mechanical method by improving the use efficiency of shale shaker,the desander,the desilter and the centrifuge.And sub-micron solid phase is flocculated and then removed by solid phase controlled equipment,through the reasonable application of solid phase cleaning agent,which control the rise of low density solid phase.The control of low density solid phase is more intuitive by the drawing and utilization of low density solid phase control curve,and the calculation of low density solid phase is more accurate by improving method of solid phase content measurement.By optimizing kinds of drilling fluid properties,which has prepared us for the change of inhibition and plugging ability of drilling fluid after low density solid phase control.It makes sure that the mechanical drilling speed can be improved and meanwhile the wellbore stability is increased after low density solid phase control.Finally,the drilling footage is fast,and the borehole is secure.Low density solid content was reduced from more than 10% to less than 6.5% by upgrading of system,equipment and treatment concept,the effect is obvious;the submicron particles which affect drilling speed of drilling machinery reduced substantially by the low density solid phase control,the drilling speed increased obviously,the drilling speed after low density control reached 35% than that before low density control in Liaohe oilfield,and we achieved good economic benefits.