摘要
讨论了水淬高炉矿渣的组成、激活原理及激活剂,指出氧化钙是适于油田井下环境的激活剂。使用组成、特性已知的一种高炉矿渣,取油井水泥、矿渣质量比为5∶3,以CaO激活,水与水泥+外掺料质量比1∶1,在120℃密闭养护24 h,矿渣水泥石抗压强度随CaO掺量(CaO与矿渣的质量比)增大而增大,掺量8%时有最大值(16.2 MPa),掺量更大时趋于下降。断面电镜照片显示,CaO掺量不足时(5%)一部分矿渣粒子以原态存在,掺量过大时(20%),过量CaO晶体夹杂在水化产物中,均引起矿渣水泥石强度下降;过量CaO在清水养护过程中可变为Ca(OH)2而被溶出,形成孔洞,造成强度下降。CaO掺量适当时矿渣粒子充分激活、水化,形成长而密集、相互交错的纤维状。CaO最佳掺量与矿渣组成有关。配浆水矿化度由2 g/L增至100 g/L时,8%CaO激活的矿渣水泥石强度在不大的幅度内上下变动,但在淡水中养护24 d后则由14.3 MPa降至7.24 MPa,这是盐被溶出而形成空洞的结果。配浆水矿化度以≤10 g/L为好。图5表3参1。
Tbe composition, principles of activation, and activators for blast furnace slag are presented and CaO is considered as the optimal activator in cement/slag slurries （C/SSs） for downhole operations in oil fields. In experiments a slag of known oxide composition and characteristics are used to prepare C/SSs at oilweU cement to slag mass ratio 5 ： 3 and water to cement ＋ slug ＋ CaO mass ratio 1：1 and the C/SSs are maintained to set in closed vessels at 120℃ over 24 hrs. It is shown that the compression strength of set slag admixtured cement （SSAC） increases with increasing CaO dosage（ as CaO to slag mass ratio in % ） and the highest value of 16.2 MPa is observed at CaO dosage 8%, the strength tends to decrease at higher CaO dosage. The SEM photographs of the fractured section demostrate that some slag particles exist in their original state at insuffident CaO dosage （5 % ） and excessive amount of CaO crystal mixed with hydration product when rather large amount （20%） of CaO is added; in these cases the strength of SSAC is lowered. The excess CaO is converted into Ca（OH）2 and the latter is easily dissolved out to create voids and pores and lower the strength of SSAC, when maintained in fresh water. At proper CaO dosage the slug particles are activated and hydrated sufficiently to form long, densely packed and interlacing fibrious hydration product. The optimal dosage of CaO is dependent on the chemical compc^sition of the slag used. When the salinity of water for slurry preparing increases from 2 g/L to 100 g/L, the strength of 8% CaO-activated SSAC varies within a little range but decreases significandy from 14.3 MPa to 7.24 MPa after maintaining the SSAC additionally in fresh water over 24 days, a result of dissolving out of salts and creation of voids and pores in the SSAC. The proper salinity of the water used for preparing the slurries is to be ≤10 g/L.
出处
《油田化学》
CAS
CSCD
北大核心
2005年第2期111-114,125,共5页
Oilfield Chemistry
关键词
高炉水淬矿渣
激活剂
氧化钙
油井水泥
掺矿渣水泥
激活/水化
blast furnace slag
activator
calcium oxide （ CaO ）
oilwell cement
slag admixtured cement
activation /hydration
