Yerniyazov Daniyar, Yesmukhambet Madi, Kenes Razida, Bukayev Azamat, Shakeel Mariam, Pourafshary Peyman, Musharova Darya
School of Mining and Geosciences, Nazarbayev University, Astana 010000, Kazakhstan.
KazMunayGas Engineering, Astana Z05H9E8, Kazakhstan.
Polymers (Basel). 2023 Apr 21;15(8):1969. doi: 10.3390/polym15081969.
Polymer flooding is one of the most widely used and effective enhanced oil recovery techniques. It can improve the macroscopic sweep efficiency of a reservoir by controlling the fractional flow of water. The applicability of polymer flooding for one of the sandstone fields in Kazakhstan was evaluated in this study and polymer screening was carried out to choose the most appropriate polymer among four hydrolyzed polyacrylamide polymer samples. Polymer samples were prepared in Caspian seawater (CSW) and assessed based on rheology, thermal stability, sensitivity to non-ionic materials and oxygen, and static adsorption. All the tests were performed at a reservoir temperature of 63 °C. Based on the results of the screening study, tolerance of a polymer towards high-temperature reservoir conditions, resistance to bacterial activity and dissolved oxygen present in make-up brine, chemical degradation, and reduced adsorption on rock surface were considered the most important screening parameters. As a result of this screening study, one out of four polymers was selected for the target field as it showed a negligible effect of bacterial activity on thermal stability. The results of static adsorption also showed 13-14% lower adsorption of the selected polymer compared to other polymers tested in the study. The results of this study demonstrate important screening criteria to be followed during polymer selection for an oilfield as the polymer should be selected based on not only polymer characteristics but also the polymer interactions with the ionic and non-ionic components of the make-up brine.
聚合物驱油是应用最广泛且有效的提高采收率技术之一。它可以通过控制水的分流来提高油藏的宏观波及效率。本研究评估了聚合物驱油在哈萨克斯坦某砂岩油田的适用性，并进行了聚合物筛选，以便从四个水解聚丙烯酰胺聚合物样品中选出最合适的聚合物。聚合物样品在里海海水（CSW）中制备，并根据流变学、热稳定性、对非离子材料和氧气的敏感性以及静态吸附进行评估。所有测试均在63℃的油藏温度下进行。基于筛选研究的结果，聚合物对高温油藏条件的耐受性、对补充盐水中存在的细菌活性和溶解氧的抗性、化学降解以及在岩石表面吸附的降低被认为是最重要的筛选参数。作为该筛选研究的结果，四种聚合物中有一种被选用于目标油田，因为它显示出细菌活性对热稳定性的影响可忽略不计。静态吸附结果还表明与研究中测试的其他聚合物相比，所选聚合物的吸附降低了13 - 14%。本研究结果表明了在为油田选择聚合物时应遵循的重要筛选标准，因为聚合物的选择不仅应基于聚合物特性，还应基于聚合物与补充盐水的离子和非离子成分之间的相互作用。
