热采井固井水泥含氯促凝剂作用机理研究

含氯促凝剂曾在稠油热采井固井中得到应用，但高温下对油井水泥石性能的影响及机理却未得到深入研究。评价了不同加量及种类的促凝剂对加砂水泥石抗压强度的影响，并深入考察了含氯促凝剂对加砂水泥石抗压强度的影响，结合X–衍射和电镜扫描分析了含氯促凝剂加砂水泥石高温前后水化产物组分和微观形貌变化，探讨了含氯促凝剂对加砂水泥石结构变化的作用机理，结果表明：水化产物硬硅钙石是水泥石高温后强度不衰退的主要原因，当温度超过230 ℃时，水泥石水化产物组分受到氯离子的影响，生成了新的斜长钙石组分，改变了水泥石微观结构，是水泥抗压强度急剧衰退的主要原因。

Study on the Mechanism of Chlorine Coagulant in Heavy Oil Thermal Wells Cementing

The chlorine coagulant has been used in thermal recovery cementation. Few in-depth researches have been made on the effects and the mechanism of oil well cementing performance under the high temperature condition. In this paper，the effects of different types and dosage of coagulant on the compressive strength of silica sand cement are evaluated，and the effects of chlorine coagulant on the compressive strength of silica sand cement is studied in detail；the structure of hydrate component and microstructure before and after high temperature are measured by means of XRD and SEM，and the functional mechanism of chlorine coagulant on the structural change of silica sand cement is discussed. The results shows that the hydration products Xonotlite is the main reason for the non-decline of the compressive strength of cement after high temperature. When the temperature exceeds 230℃，the component of hydration products of cement is affected by the chloride ions，generating a new inclined long calcium stone component，and changing the microstructure of cement，which is the main reason for the sharp decline of the compressive strength.