热采井预压固井技术

计算表明，注蒸汽稠油井如果用常规方法固井，在通常的注汽温度下，套管都因热应力而产生屈服变形。目前现场常用的防止套管热破坏方法不能从根本上解决问题。提出了热采井预压固井技术，即在注水泥结束后，向油层套管施加压力，使套管膨胀。计算实例表明，采用预压固井技术后，热采井在整个生产周期内，套管不但正常，而且还有较大的安全系数。给出了热采过程中，套管内应力的计算模型。

Pre-pressured Cementing for Thermal Recovery Wells

Casing is heated by steam in thermal recovery wells. There are thermal stresses in casing. Casing deforms when stresses exceed yield point. If using conventional cementing technology for thermal recovery wells, casing deforms due to thermal stresses. Technologies conventional used to protect casing from failure are inefficacy theoretically. The pre-pressured cementing technique for thermal recovery well refers to exert compressions on production casing and make it expand after cementing operation. Calculations show that casings being pre-pressured performs greater safety coefficient during the whole production cycle. Finally, the casing inner stress model is presented for thermal recovery wells.