Research Of Drilling With PDM And PDC Bit In Dagang Oilfield

The experimental application of drilling with PDM and PDC bit begins from the 90 s last century. With the progress of PDM performance and increase in both the type of downhole motor and high-efficiency PDC bit, in this 10 years it has become the most used drilling acceleration technical method in Dagang. The raising of proportion of BHA with PDM and PDC bit application is by reason of a good formation drillability. In Dagang oilfield, formation mainly consists of mudstone and sandstone. Upper formation is relatively unconsolidated and shows a poor diagenetic grade while under formation performs a resistant lithologic character. The stable formation and good drillability generate a popular applying of BHA with PDM and PDC bit in Dagang.PDC bit requires a high RPM and a low bit pressure, meanwhile, PDM can produce a high RPM. Therefore, the enhancement of penetration rate could rely on the optimization of PDM, PDC bit and drilling parameters. At the same time, applying PDM could reduce the RPM of wellhead and the abrasion of drill pipes in the bore hole. This brings a decreasing in amount of drilling stem accident. Application of BHA with PDM and PDC bit could also shortening the period and lower the cost to guarantee the drilling engineering with a better quality, higher yield and more stable production.