Whisker Material Enhances The Mechanical Properties And Mechanism Of Oil Well Cement Stone

Oil-well cementing is one of the important part for contacting the drilling and exploitation in oil and gas project. With the difficulty increase in oil-gas filed development, it becomes harder to make a better interlayer isolation, in which keeping a good work on mechanical properties for cement sheath is the most significant factor. Due to the brittleness of cement paste, it would fail to protect the interlayer isolation owing it broken down when something stress on it, such as drilling and fracturing operation.For solving the problem and improving the properties of cement sheath, the current paper did a investigation about the brittleness cause of cement paste. According to the results, a research was been proceeded, which was about the influence on the mechanical properties of cement composites by adding silicic and zincate whiskers. The results showed that both of the whiskers could do good effect on the mechanical properties of cement composites. The silicic whiskers could improve the mechanical properties of oil-well cement composites and decrease the elasticity modulus. The properties of cement paste hydrated for 28 days was greatly improved for the increasing to 125.7,35.1 and 17.5% on the tensile strength, flexibility and compressive strength respectively. And the elasticity modulus was decreased to 28.0% compared with the virgin cement. Otherwise, the same effect was happened to the zincate whiskers cement composites, such as the tensile and flexibility increased to 132.1% and 28.8%, with the 24.6% duce on elasticity modulus.In addition, this paper used kinds of technology to analyzing the difference on the different composites by X-ray diffraction and IR. And the results indicated that there was nothing new become after adding the either whiskers, with something different in zincate composites observed by SEM. According to the results two improving mechanism were concluded. For the first one is that the silicic whiskers can not do effect on the hydrations of cement composites, but can improve the mechanical properties by cracking-bridge, crack-deflection and pull-out of whiskers. Due to the special three-dimensional structure of zincate whiskers, the unformed hydration structure can be altered into "flowerlike" hydrations. And the special hydrations can improving the mechanical properties by minishing the stress the composites suffered.In generally, both of the whiskers could reinforce the properties of oil-well cemnt composites. They could remain the mechanical intergrity and provide a theory base on the relevant study.