Research On Complex Process Treatment Technology Under MPD Conditions In Tazhong Area

In the Tarim Basin,the Ordovician fractures are developed in the Tazhong area,and the reservoirs are deep,mostly deep wells,ultra-deep wells and horizontal wells,extremely easy to cause underground complex accidents about the overflow,well leak,kick and loss in the same layer,and so on.The application of managed pressure drilling technology in the Tazhong is an effective way to solve the above-mentioned problems,and it is more and more important to how to deal with the complicated downhole conditions correctly and timely under the managed pressure drilling.Based on the basic theory of managed pressure drilling technology for overflow and loss,this paper combines the geological characteristics of Tazhong area,and carried out research on the complex working condition of managed pressure drilling in Tazhong area,through the field application has achieved the following results:1、Based on the analysis of the mechanism of overflow and the actual situation of managed pressure drilling,this paper through optimization the related gas model、drilling fluid、density model and downhole pressure change model,perfect the the processing technology of wellhead back pressure real-time control overflow according to bottom hole pressure change,and the technical process of controlling overflow complex conditions in managed pressure drilling.Based on the field data of the well in the Tazhong area,The reasonableness of overflow technology for managed pressure drilling has been verified.2、Based on the analysis of the mechanism of loss and the actual situation of managed pressure drilling.this paper through optimization the relevant fracture model and the bottomhole pressure change model,perfect the processing technology of wellhead back pressure real-time control loss according to bottom hole pressure change,and the technical process of controlling loss complex conditions in managed pressure drilling.Based on the field data of the well in the Tazhong area,The reasonableness of loss technology for managed pressure drilling has been verified.3、through researching the riser pressure changes and riser pressure,annulus pressure signal propagation time difference,put forward the technology of relying on the pressure change of the riser for leak detection location and the technology of signal time difference leak location detection,using the field data in Tazhong area verify the feasibility and applicability of these two kinds of the leak layer location technology.Through the research in this paper,making the managed pressure drilling technology in the Tazhong area is more perfect and reasonable,and it is of great significance to deal with the complicated situation of the underground well with accurate and effective operation for MPD.