影响四川地区天然气井固井质量的地质因素分析及对策

Analysis on Geologic Factors Affecting Cementing Qualities of Natural Gas Wells in Sichuan Area

四川地区天然气井固井的复杂性和挑战性归根结底源于地质条件的复杂性;正确认识井下地质特点对固井工程的影响、摸清井下地质特点,是制定合理的工艺措施、设计优质的水泥浆体系、建立完善的应急预案的基础。分析了影响四川盆地天然气井固井质量的4大地质因素:井下漏失严重、压力系统复杂、含酸性气体以及存在膏盐岩层,并针对每一种地质因素,从工艺设计、现场施工、水泥浆设计以及外加剂选择等多方面进行了固井技术对策研究。

In Sichuan area,the challenges of cementing in natural gas wells are complex geology,which is the key to develop appropriate technologic measures,design high quality cement slurry and establish complete emergency plans.Moreover,the mainly four geologic factors affecting the cementing qualities are severe mud loss,complicated pressure systems,acid gas and gypsum salt formation.Also the treatments to each geologic factors are analyzed from operation,cement slurry design and cement additives.