Study On Cementing Technology Of High Pressure Gas Well For Marine Phase In Northeast Sichuan

The natural gas reservoir in Northeast Sichuan Exploration Block is geologically named by Feixianguan Group,Jialingjiang Group,and most completion well depth range between 5000m and 6000m.Due to these complex geological structure and depth of target zone,HT,HP, multi pressure gradient and differential always cause problems for cementing operation.How to improve cementing quality,gas channeling mechanism and preventinon measures are studied in this paper.A reasonable balanced pressure cementing programme and coefficient Fsur for HP gas well in Northease Sichuan are determined.A high density,gas channeling prevention slurry system added with DZJ-2/FSAM,latex slurry LX200 are developed especially for those high pressure gas wells.To shoot the problem of kick-out and leakage occuring in the same layer, Anti-leakage Fiber is studied and tested in lab to demonstrate its capacity for improving cementing problems.MS-R Pre-flush with a density between 1.1 g/cm3 and 2.3g/cm3 has been developed for a high ionic underhole conditions in Northeat Sichuan.The entire technique has been applied in over ten wells distributed in Puguang Structure,Laojun Structure,Qingxi Structure,Tong Nanba Structure as well as Maoba Structure.Applications showed that the technique is able to improve cementing quality and suitable for the exploration of this area.