Research On Anti-collapse Drilling Fluid Technology Of Deep Well In Xinchang, Western Sichuan

In order to solve the unstable borehole face of Western Sichuan New field, studied the domestic and foreign anti-collapse drilling technology, analyzed engineering geological formation characteristic completely, carried out the analysis of the mechanism of wellbore instability. The lithology of formation which more easily to collapse, rock structure, physical and chemical properties, X-ray diffraction analysis and thin section layers were analyzed, it drew a conclusion that the shale formation of Qianfoyazu and Xuwuduan belong to brittle shale and they exist micro-cracks and fissures, the technical strategy of deephole anti-collapse drilling fluid was proposed. Through a large number of experimental studies, good inhibitor polyamine UHIB/silicone wellbore stabilizer, Wall mounting medium FGL, blocking agent FST-2, film-forming sealer JYW-2, the deformable seal blocking material FDFT-1 were selected out. One type of deephole anti-collapse treatment agent system was formed and it contains strong blocking metal ions drilling fluid system and silicate drilling system. By testing applications on XC7 well, X13 Well, X916-1 wells, X209 wells and so on, it demonstrated that the anti-collapse drilling fluid can reduce the downhole wellbore instability significantly and it had protected the drilling operations effectively. It formed a completely new deep anti-collapse drilling fluid techonoly which can solve the issue of Western Sichuan Newfield borehole by field application test and constantly improved.