Optimization and Application of Water Based Drilling Fluid for Adjusting Well in Weizhou 11-1 Oilfield
Weizhou 11-1 oilfield is located in the Beibu Gulf of the South China Sea.The Zhongxin Formation Dengloujiao Formation and Jiaowei Formation encountered during drilling are key formations.The upper part of the Jiaowei Formation has a high content of mud,and when using conventional strong coating drilling fluid operations,it is very easy for drill cuttings to accumulate and form mudballs,which not only affects drilling efficiency,but also may cause resistance during tripping operations.In order to solve this problem and improve the reservoir protection effect of the middle and lower sandstone layers in the Jiaocaizhu Formation,through analyzing relevant data from previous drilling operations,we have optimized and selected sea water polymer drilling fluid and EZFLOW non-solid drilling fluid.Compared to the strong coating type PDF-PLUS/KCl drilling fluid,the sea water polymer drilling fluid has better dispersibility and can effectively prevent the formation of mud balls,while the EZFLOW non-solid drilling fluid has strong shear thinning properties,superior suspension and carrying performance,as well as better reservoir protection performance.Successful applications in two adjustment wells at the a platform of the Weizhou 11-1 oilfield have demonstrated that the optimized drilling fluid effectively improves the problem of mud balls in the Jiaocaizhu Formation,while enhancing the efficiency of drill string lowering and reservoir protection.
NETL
NSTL
万方数据
维普
