Mohammed Isah, Al Shehri Dhafer, Mahmoud Mohamed, Kamal Muhammad Shahzad, Alade Olalekan Saheed
Petroleum Engineering Department, College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia.
Center for Integrative Petroleum Research (CIPR), College of Petroleum Engineering and Geosciences, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia.
ACS Omega. 2021 Jan 27;6(5):4022-4033. doi: 10.1021/acsomega.0c05954. eCollection 2021 Feb 9.
Asphaltene adsorption and deposition onto rock surfaces are predominantly the cause of wettability and permeability alterations which result in well productivity losses. These alterations can be induced by rock-fluid interactions which are affected by well operations such as acidizing, stimulation, gas injections, and so forth. Iron minerals are found abundantly in sandstone reservoir formations and pose a problem by precipitation and adsorption of polar crude components. This is due to rock-fluid interactions, which are dependent on reservoir pH; thus, this research work studied the surface charge development of pyrite, magnetite, and hematite. To ascertain conditions that will result in iron mineral precipitation and adsorption of asphaltene on iron mineral surfaces, zeta potential measurement was carried out. This is to determine the charge and colloidal stability of the iron mineral samples across wide pH values. Experimental results show that the charge development of iron minerals is controlled by mineral dissolution, the formation of complexes, adsorption of ions on the mineral surface, and the collapse of the double layer. The findings provide insights into the implications of iron mineral contacting crude oil in reservoir formations and how they contribute to wettability alterations due to different well operations.
沥青质在岩石表面的吸附和沉积主要是导致润湿性和渗透率改变的原因，而这些改变会造成油井产能损失。这些改变可能由岩石与流体的相互作用引发，而这种相互作用会受到诸如酸化、增产措施、注气等油井作业的影响。铁矿物在砂岩储层中大量存在，会因极性原油成分的沉淀和吸附而引发问题。这是由于岩石与流体的相互作用取决于储层的pH值；因此，本研究工作对黄铁矿、磁铁矿和赤铁矿的表面电荷发展进行了研究。为了确定会导致铁矿物沉淀以及沥青质在铁矿物表面吸附的条件，进行了zeta电位测量。这是为了确定铁矿物样品在较宽pH值范围内的电荷和胶体稳定性。实验结果表明，铁矿物的电荷发展受矿物溶解、络合物形成、离子在矿物表面的吸附以及双电层的坍塌控制。这些发现为储层中铁矿物与原油接触的影响以及它们如何因不同的油井作业导致润湿性改变提供了见解。
