水泥浆胶凝期间套管柱受力和形变规律

套管柱注水泥结束后 ,由于水化热的作用使水泥浆在胶凝过程中产生升温现象 ,并随之失重。温度、压力的共同作用会使套管柱发生很大的形变。随着水泥的固化 ,这种形变也会被固结在水泥封固段内 ,影响其使用性能。在调研大量资料的基础上 ,利用数值计算方法得到了水泥胶凝过程中温度变化的动态数据。对某油田实测数据进行了统计分析 ,得出了水泥浆失重时的压力计算公式。根据有限元理论 ,推导出套管段长度与温度、压力、水泥及套管表面剪切应力之间的关系式。在此基础上 ,计算得到了水泥浆胶凝过程中套管的动态变化。

Mechanics of Deformation of Casing String During Primary Cementing

During the primary cementing, wellbore temperature rises because of hydration heat of cement slurry accompanying its pressure reduction. The combined effect of annular temperature and pressure can change working conditions of casing string. After cementing, these changes are solidified in cementing interval, which affects the performances of casing in its whole life. The data of wellbore temperature response of a hole in primary cementing are obtained by numerical computation and simulation. Pressure formula is established with a statistical method. The relationship among casing string length, annular temperature and pressure, shear stress along with the surfaces of casing tube is founded using the finite element theory. On the basis above, a finite element solution is obtained. The time dependent stress and strain response in casing string during primary cementing are investigated. Some data about damage of casing can be obtained by numerical computation.