MEASUREMENT SYSTEM OF CEMENT SHEATH STRAIN

Rigidification of the cement slurry usually leads to volume shrinkage, which in turn produces micro annular gap at the secondary contact and impacts the cementing quality. To quantify the expansion and shrinkage of the cement sheath, a cement sheath strain measurement system is established according to the downhole state of cement slurry after cementing and formation hardness. This system is used to measure the expansion and shrinkage of cement sheath, and the strains on the primary and secondary contacts are then worked out. The strain measurement system was used to evaluate different cement slurry systems and the results showed that class A slurry obtained the same result as that of field data, which further proved the reliability of the system. The DPD expansion cement slurry system evaluated by the system exhibits remarkable effect in the adjustment well cementing of time delay logging in Daqing Oilfield.