Mechanistic Understanding of the Impact of EOR Polymer on the Inhibition Mechanism and Performance of Phosphonate Scale Inhibitors

Abstract

With the current trend for application of Enhanced Oil Recovery (EOR) technologies, there has been much research into the possible upsets to production, from the nature of the produced fluids to changes in the scaling regime. The key question being addressed in this publication is the influence of EOR chemicals, such as hydrolyzed polyacrylamide (HPAM), on scale inhibitor (SI) squeeze lifetime for barium sulphate and calcium carbonate scale risk. Squeeze lifetime is defined as the duration of time (or produced water volume) before the minimum inhibitor concentration (MIC) is reached. This is controlled by the adsorption, and later release, of the inhibitor onto the reservoir rock and the MIC of the inhibitor selected for the produced brine. This paper builds on earlier published work investigating potential changes to inhibitor adsorption caused by polymer EOR produced and moves to the evaluation of the changes in MIC due to the presence of EOR chemical. In the static inhibitor performance bottle tests, the EOR polymer alone appeared to show some degree of inhibition performance against BaSO4, but below a level required for effective scale management. However, in combination with the inhibitor (DETPMP) at near MIC levels, the inhibition efficiency was negatively impacted by the presence of degraded HPAM EOR polymer. During dynamic tube blocking tests, the inclusion of even low levels of HPAM (2.5 ppm) were shown to reduce the differential pressure build up suggesting barite scale inhibition or reduced adhesion to the coil. Furthermore, the scale morphology produced in these tests, examined under a scanning electron microscope, was clearly impacted in the presence of HPAM. For the CaCO3 system there appears to be increasing positive impact from HPAM on CaCO3 morphology with HPAM concentration and, as observed for BaSO4, an improved performance in dynamic efficiency experiments. However, at higher HPAM concentrations (500 ppm) the precipitate was amorphous and only a minor pressure rise was observed during the tube blocking experiments. From these observations, it is clear that HPAM can impact the way both calcite and barite scale grow, especially at lower inhibitor concentrations (

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提高采收率聚合物对膦酸盐阻垢剂缓蚀机理和性能影响的机理研究

随着目前提高采收率(EOR)技术的应用趋势，从产出流体的性质到结垢状态的变化，人们对可能对生产造成的影响进行了大量研究。本出版物中要解决的关键问题是EOR化学品(如水解聚丙烯酰胺(HPAM))对硫酸钡和碳酸钙结垢风险的阻垢剂(SI)挤压寿命的影响。挤压寿命定义为达到最小抑制剂浓度(MIC)之前的时间(或产出水量)。这是由抑制剂在储层岩石上的吸附和释放以及为生产的盐水选择的抑制剂的MIC控制的。本文以早期发表的研究成果为基础，研究了聚合物提高采收率对抑制剂吸附的潜在影响，并进一步评估了提高采收率化学品的存在对MIC的影响。在静态抑制剂性能瓶测试中，EOR聚合物单独对BaSO4表现出一定程度的抑制性能，但低于有效控制结垢所需的水平。然而，与接近MIC水平的抑制剂(DETPMP)联合使用时，降解的HPAM EOR聚合物的存在对抑制效率产生了负面影响。在动态管阻塞测试中，即使是低水平的HPAM (2.5 ppm)也可以减少压差的积累，这表明重晶石阻垢作用或减少了对线圈的粘附。此外，在扫描电子显微镜下检查，这些测试中产生的鳞片形态在HPAM的存在下明显受到影响。对于CaCO3体系，HPAM对CaCO3形态的积极影响似乎随着HPAM浓度的增加而增加，并且正如在动态效率实验中观察到的那样，对BaSO4的性能有所提高。然而，在较高的HPAM浓度(500 ppm)下，沉淀是无定形的，在管堵塞实验中只观察到轻微的压力上升。从这些观察结果可以清楚地看出，HPAM可以影响方解石和重晶石垢的生长方式，特别是在较低抑制剂浓度(

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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