Cementing technology of glycoside drilling fluid under well condition

For strong water sensitive of hard and brittle shales of Weizhou formation in Beibu gulf sea area of the South China Sea,the complicated accidents such as borehole collapse,drill pipe sticking,and so on usually happed before drilling by conventional water-based drilling fluids.In 2007,a new type water-based fluid named SMB glycoside drilling fluids system is selected in WZH6-9-3 exploratory well operation.The new type fluid which is not only of good inhibition and lubricity but also can meet environmental emission requirement is very suitable for drilling operation of water sensitive formation.Although SMB drilling fluid system is of many merits,its main component glycoside is of strong retarding effect on cementing slurry,which brings very serious influence for subsequent completion,especially cementing.In cementing with ?244.48 mm casing of this exploration well,in view of the above cementing difficulties,studies many laboratories,selected cement slurry system influenced little by glycoside drilling fluid and developed a new type prepositive flush fluid especially for glycoside drilling fluid.Finally,by the above cementing technical measures,the cementing in the well section has smooth construction and good cementing quality,meeting test requirements completely.