New-type of apparatus and method of researching cement slurry swelling rate

With the development of cementing technology, the physical and chemical performances research of cement slurry is paid more and more attention. A kind of micro-swelling cement is developed faced on the shortage of chemical shrinkage of normal oil well cement after set. So how to measure the swelling time and capacity is a key of studying the micro-swelling cement. In this paper, the liability of swelling rate test apparatus is examined firstly, and the studying results show that with time passing, the cement slurry first swells and then shrinks, finally tends to be stable, and in cement hydration, the new product is the direct cause of the volumetric shrinkage of cement slurry, moreover, without the environmental affection, the swelling rate is mainly changed in the process of from thickening transition time start point (30 Be) to early compressive strength formed, and different slurries have different swelling and shrinkage capacities.