聚合醇抑制性能评价研究

聚合醇在实际的钻井应用中,由于其固有的特性,无论是井眼温度高于还是低于浊点温度,对页岩都有一定的抑制作用,但机理不同.本文选择浊点温度在80 ℃左右的聚合醇,采用YPM-03页岩膨胀模拟试验装置进行试验,旨在验证浊点上下聚合醇抑制作用受到温度、压力及其浓度等因素的影响.室内对聚合醇在不同浓度下的抑制性以及温度、压力对其抑制性的影响规律进行了试验研究.结果发现,1)采用页岩膨胀模拟试验装置能够检测出聚合醇样品对膨润土样品抑制性在不同温度、压力条件下的变化,仪器的测试精度和重复性均能满足试验要求,这种检验方法是可行的.2)随着温度的变化,聚合醇对膨润土的抑制性能呈现出很大的差异,在浊点温度以下,抑制性能很好,而在浊点温度以上,其抑制性能迅速降低.3)在浊点温度以上,随着浓度的增加,聚合醇对膨润土的抑制性增强,但在较低浓度时,抑制效果不明显;只有达到较高浓度时,才呈现出较好的抑制性;随着压力的增大,聚合醇浓度较低时,抑制性不理想;当聚合醇浓度较高时,随压力的增大,即抑制性增强.

Study on the inhibitive behavior of polyalcohol

Polyalcohol drilling fluid has been widely used in drilling due to its good lubrication, inhibition and environmental acceptance. But the inhibitive behavior appears different in different conditions. In order to understand the inhibitive property, YPM-03 shale swelling simulator was adopted to study the effect of concentration, temperature and pressure. Tests results demonstrated that, at a destined testing condition, the inhibiting ability increases with the increase of polyalcohol concentration, and decreases with the increase of temperature; at low concentration, the inhibiting characteristic changes little with the pressure increasing, but at higher concentration, it is improved. As at low concentration, the inhibition of polyalcohol is not clear, the concentration should at above 10% to achieve ideal inhibition for shale. Lab tests also directed that the method evaluating inhibitive behavior of polyalcohol using YPM-03 shale swelling simulator is feasible.