Study On Expansion And Tenacity Character In Oil-well Cement Mixing Slag

G Oil-well cement is the kind of cement material which is largely used in oil well and gas well engineering. According to API Standard, it can show a good performance at the depth of 0~2240m, and the temperature of 0～93℃。 Cement paste is the main material of cement annulus in wells which is with responsibility for hanging and protecting the tubes. Normal oil-well cement has two disadvantages such as brittleness and volume shrinkage at setting course. Slag power has been widely used as an integrant component in high performance concrete (hpc). It has been accepted that the adding of slag can decrease porosity and amend pore structure so as to improve the capability of concrete in theory. In recent years, slag is mostly used as a kind of admixture in ordinary cement calcine which can be made as slag cement to improve the performance of ordinary cement.In this thesis, phosphor and slag are added in oil-well cement. On the basis of mechanical characteristic of cement paste, we find slag is the better admixture in improving oil-well cement performance, and the best ration is 30%. Further more, we find the use of gypsum and vitriol can accelerate the rate of hydration, improve early strength, swell in water cure of 50℃ and make up for the constriction of volume.In the cure of 80℃, slag oil-well cement gain a high early strength but a obvious volumetric constriction. This paper studied the effects of various of expanders and their rations are also discussed .The results show that in the cure of 80℃,oil-well cements with 5% compound expander may gain an ideal self-generate volume expand curve(the early expansion is about 0.05%,and the 14d-expansion is 0.073%,the later expansion is about 0.07%).According to the porosity data, adding an amount of compound expander will gain more gel pores and less capillary pores and big pores. And these facts indicate that the adding of expander can improve strength and other prosperities. By analyzing the appearance of cement hydration, oil-well cement with 3% expander make the micro structure of cement system denser and the mechanical prosperities of oil-well cement system are improved.For better the proportion of mechanical properties of G oil-well cement and...