Shahat John S, Soliman Ahmed Ashraf, Gomaa Sayed, Attia Attia Mahmoud
Petroleum Engineering and Gas Technology Department, Faculty of Energy and Environmental Engineering, British University in Egypt (BUE), El Sherouk City 11837, Cairo, Egypt.
Mining and Petroleum Engineering Department, Faculty of Engineering, Al-Azhar University, Cairo 11651, Egypt.
ACS Omega. 2023 May 24;8(22):19509-19522. doi: 10.1021/acsomega.3c00904. eCollection 2023 Jun 6.
The world is gradually moving toward a severe energy crisis, with an ever-increasing demand for energy overstepping its supply. Therefore, the energy crisis in the world has shed important light on the need for enhanced oil recovery to provide an affordable energy supply. Inaccurate reservoir characterization may lead to the failure of enhanced oil recovery projects. Thus, the accurate establishment of reservoir characterization techniques is required to successfully plan and execute the enhanced oil recovery projects. The main objective of this research is to obtain an accurate approach that can be used to estimate rock types, flow zone indicators, permeability, tortuosity, and irreducible water saturation for uncored wells based on electrical rock properties that were obtained from only logging tools. The new technique is obtained by modifying the Resistivity Zone Index (RZI) equation that was presented by Shahat et al. by taking the tortuosity factor into consideration. When true formation resistivity () and inverse porosity (1/Φ) are correlated on a log-log scale, unit slope parallel straight lines are produced, where each line represents a distinct electrical flow unit (EFU). Each line's intercept with the -axis at 1/Φ = 1 yields a unique parameter specified as the Electrical Tortuosity Index (ETI). The proposed approach was validated successfully by testing it on log data from 21 logged wells and comparing it to the Amaefule technique, which was applied to 1135 core samples taken from the same reservoir. Electrical Tortuosity Index (ETI) values show marked accuracy for representing reservoir compared with Flow Zone Indicator (FZI) values obtained by the Amaefule technique and Resistivity Zone Index (RZI) values obtained by the Shahat et al. technique, with correlation coefficients of determination () values equal to 0.98 and 0.99, respectively. Hence, by using the new technique, the Flow Zone Indicator, permeability, tortuosity, and irreducible water saturation were estimated and then compared with the obtained results from the core analysis, which showed a great match with the -values of 0.98, 0.96, 0.98, and 0.99, respectively.
世界正逐渐走向严重的能源危机，对能源的需求不断增加，已超出其供应能力。因此，世界能源危机凸显了提高石油采收率以提供可负担得起的能源供应的必要性。储层表征不准确可能导致提高石油采收率项目失败。因此，需要准确建立储层表征技术，以成功规划和实施提高石油采收率项目。本研究的主要目标是获得一种准确的方法，该方法可用于基于仅从测井工具获得的岩石电学性质来估计未取芯井的岩石类型、流动带指标、渗透率、迂曲度和束缚水饱和度。通过考虑迂曲度因子修改Shahat等人提出的电阻率带指数（RZI）方程，得到了新技术。当真地层电阻率（）与反孔隙度（1/Φ）在对数-对数尺度上相关时，会产生单位斜率的平行直线，其中每条线代表一个不同的电流动单元（EFU）。每条线在1/Φ = 1时与-轴的截距产生一个唯一的参数，指定为电迂曲度指数（ETI）。通过对21口测井井的测井数据进行测试，并将其与应用于从同一储层采集的1135个岩芯样本的Amaefule技术进行比较，成功验证了所提出的方法。与通过Amaefule技术获得的流动带指标（FZI）值和通过Shahat等人的技术获得的电阻率带指数（RZI）值相比，电迂曲度指数（ETI）值在表征储层方面显示出显著的准确性，决定系数（）值的相关系数分别等于0.98和0.99。因此，通过使用新技术，估计了流动带指标、渗透率、迂曲度和束缚水饱和度，然后与岩芯分析得到的结果进行比较，结果显示与-值分别为0.98、0.96、0.98和0.99时非常匹配。
