【摘要】 针对富含CO₂的高温高压油气井中水泥环的腐蚀问题，进行了高温高密度防腐水泥浆体系加重剂的研究，并对比了相同粒度的锰矿粉、赤铁矿和重晶石3种加重剂对水泥浆性能的影响，在150℃、CO₂分压20 MPa的环境下进行了腐蚀实验。研究结果表明，锰矿粉水泥浆需水量最少，相同条件下具有较好的流变性和较低的失水量；锰矿粉水泥石腐蚀后渗透率最小，抗压强度较高；腐蚀30 d后，锰矿粉水泥石腐蚀深度最低，重晶石水泥石的腐蚀深度约为锰矿粉水泥石的1.5倍；腐蚀后锰矿粉水泥石结构最致密，腐蚀后生成物的特征峰最低；锰矿粉加量为25%、50%和75%的3种水泥石腐蚀27 d后，加量为50%的水泥石腐蚀深度最小。与赤铁矿和重晶石相比，锰矿粉为较好的选择，但加量过多时会对水泥浆防腐蚀性能产生不利影响。更多还原

【Abstract】 High temperature high pressures wells rich in CO2 are often faced with the corrosion of cement sheaths. In this study, a suitable weighting agent for high temperature high density corrosion inhibitive cement slurries was selected, and the effects of three weighting agents on the properties of cement slurries were compared. These three weighting agents include manganese ore powder,hematite and barite, which have the same particle size distribution. The corrosion test was performed at 150 °C and CO₂ partial pressure of 20 MPa. The study results showed that the cement slurry weighted with manganese powder requires the least amount of water, and thus has good rheology and lower filtration rate in the same conditions. The set cement of the manganese powder treated cement slurry has the lowest permeability and higher compressive strength after corrosion test. After 30 d of corrosion, the corrosion depth of the manganese set cement is the minimum among others, the corrosion depth of the barite set cement is 1.5 times of the corrosion depth of the manganese set cement. After corrosion, the manganese set cement has the densest structure, and the characteristic peak of the corrosion products is the lowest. Among the three cement slurries treated with 25%, 50% and 75%manganese ore powder respectively, the corrosion depth of the set cement from the cement slurry containing 50% manganese ore powder is the minimum after 27 d of corrosion. Compared with the other two weighting agents, the manganese ore powder is a better choice, only over treatment of the cement slurry with the manganese ore powder should be avoided to prevent negative effects on the corrosion property of the cement slurry.更多还原