泌阳凹陷西斜坡井楼背斜区套损机理研究

Casing damage mechanism research of Jinglou Anticline of west slope in Biyang Sag

根据井楼背斜区套损井发生套损的井段分布特点,结合区域地层发育风化壳和稠油热采造成蒸汽外窜等地质和工程特点,探讨了井楼背斜地区套损井套损主控因素。研究表明:井楼一区套损发生在构造的高部位,套损点对应的层位为经过风化剥蚀作用形成的风化壳。风化壳存在蒸汽窜入所需的渗透条件,对套管损坏起控制作用。注入蒸汽通过套管错断口或者断层窜入风化壳后形成"汽冒",超过临界压力后导致套管剪切错断,是套损的触发条件。井温测井和生产数据证实了高温高压"汽冒"的存在。套损主控因素的认识为套损治理打下了基础。

This paper discusses main controlling factors of the casing damage through study of casing damage layer and the injected steam entered into the weathered crust. It is concluded that in Jinglou anticline, the casing damage occurred in high position of the structure. The casing damage is controlled by weathered crust and triggered by injected steam. The per- meable characteristics of weathered crust resulted in the entering of injected steam into the weathered crust, and the ＂steam cap＂ was formed. The casing would be sheared and bad broken when the pressure in weathered crust is over critical pres- sure. Temperature logging and production data indicated the existence of high pressure and high temperature ＂steam cap＂. The understanding of casing mechanism will provide a base for the prevention of casing damage.