Response characteristics and novel understandings of dual induction logging of horizontal wells in fractured reservoirs

• Published in: Journal of applied geophysics 2024-06, Vol.225, p.105393, Article 105393
• Main Authors: Wei, Kangjian, Qin, Zhen, Wang, Cheng, Zhang, Zhiqiang, Su, Kejia, Wang, Gang, Zhu, Yunfeng, Huang, Yicong, Zhang, Xinyi, Meng, Lingyi
• Format: Article
• Language: English
• Subjects: Dual induction logging; Finite element method; Fractured reservoirs; Horizontal well; Logging response
• ISSN: 0926-9851; 1879-1859
• DOI: 10.1016/j.jappgeo.2024.105393

Previous studies commonly used dual laterolog or induction logging in vertical wells to study fractured reservoirs. However, there are few studies about the response characteristics of dual induction logging of horizontal wells in fractured reservoirs, which interferes with the evaluation of horizontal wells in fractured reservoirs. In this study, firstly, the finite element method is used to establish the fractured reservoir model and the dual induction instrument of horizontal well. Then, the response characteristics of dual induction logging in fractured reservoirs with different fracture conductivity, fracture dip angle, fracture width and fracture length are simulated and analyzed. The results show the response characteristics as follows: (1) The apparent conductivity of dual induction logging increases first and then decreases along with the increase of fracture conductivity, when the fracture conductivity is lower than formation conductivity, the apparent conductivity is similar to formation conductivity; (2) The fracture dip angle has little effect on the apparent conductivity of induction logging, when the fracture conductivity is high, the apparent conductivity decreases with the increase of the fracture dip angle; (3) The effect of fracture width and fracture length on apparent conductivity is similar. The larger the fracture width or length, the greater their influence on the apparent conductivity, which is different from the response characteristics of laterologs. In applications, these characteristics can be demonstrated by two wells in the southwest Ordos Basin, China. Finally, advantages and disadvantages of the simulation method, applications, logging responses discussed in detail, as well as the response characteristics and the shielding effect of fractures on electromagnetic waves of dual induction instrument are discussed in detail. The applications and discussions show that this study can provide response characteristics and novel understandings for the evaluations of horizontal wells in fractured reservoirs, especially in areas where dual induction logging is widely used. •The dual induction logging responses of horizontal well in fractured reservoirs were simulated.•The influences of fracture occurrence on dual induction logging were analyzed.•The shielding effect of fractures on the electromagnetic signal of dual induction tools is discussed.