低密度水泥浆固井质量评价刻度试验研究

Calibration Experimental Study on Cementing Evaluation with Low Density Slurry

为了对低密度水泥浆固井质量进行评价,建造了低密度水泥浆固井质量模型。通过模拟试验研究了水泥浆固结硬化为水泥石的一段时间内,其声波速度、声阻抗及抗压强度、剪切力等参数的变化规律。试验表明,水泥浆中使用了添加剂后,水泥固结时间延长;水泥石的剪切力和抗压强度随水泥浆凝固时间增加而增加。低密度水泥石的抗压强度和剪切力更小,使用低密度水泥浆固井时要求层间封隔的距离比常规水泥浆固井要长才能起到封固作用。进行了低密度水泥浆固井第Ⅰ界面固井评价刻度试验,采用声幅相对值法和胶结比法得到第Ⅰ界面固井质量评价标准。该试验结果为正确评价低密度水泥浆固井质量提供了依据。

An experimental model is built to evaluate low density slurry cementation quality. By use of calibration experiment simulation, studied is the change law of parameters in slurry consol- idation period, such as acoustic wave velocity, acoustic impedance, compression strength, shear force and so on. Experiment shows that cement consolidation time will extend when adding addi- tive in cement paste^Set cement shear force and compression strength increase along with cement paste coagulation time increasing. Because the set cement with low density slurry has weaker shear force and compression strength, it needs longer interlayer sealing distance for better well cementation. Processed is cementing quality evaluation calibration experiment for the I interface with low density slurry cementing. Obtained is the I interface cementing evaluation standard from acoustic amplitude relative value method and cementing ratio method. This experiment provides references for properly evaluating low density slurry cementing quality.