Improving geosteering performance using rate of penetration and gas ratio: case studies in a limestone reservoir

Geosteering is an essential method employed in oil and gas drilling, particularly for horizontal wells, to precisely locate the wellbore within hydrocarbon-rich formations. To carry out this process, the gamma-ray logs from the laterals are matched with logs from a reference vertical well to position the lateral in the desired path accurately. Numerous studies have been carried out in the field of geosteering, focusing on the application of machine learning and the creation of automated geosteering methods. Due to the high cost of repeated use of steering, it can be helpful to establish a logical mathematical correlation between two or more parameters for movement within the reservoir. This study investigates the relationship between Rate of Penetration (ROP) and gas ratio data in three laterals drilled in a heterogeneous limestone reservoir in Iran by plotting normalized ROP vs. normalized gas ratio. Geomaster software is used to direct the geosteering process in order to ascertain the reservoir’s depth. Once the ROP and gas ratio data have been normalized and outliers removed, different models such as linear, polynomial, power, and exponential are utilized in MATLAB. As a result, we can observe that for the majority of laterals, the second-degree polynomial model offers the best correlation. Also, the presence of heterogeneity affects some results of laterals. These results can be applied to reduce the expenses associated with recurrent geosteering operations, enable the drilling of new or extended laterals, and optimize drilling operations in the field.

کلیدواژه ها:

Gas ratio ، Geosteering ، Rate of Penetration ، Limestone reservoir ، Drilling optimization