A methodology for the mapping of acoustic impedance and porosity in the inter-well region using seismic inversion based on the Hooke and Jeeves algorithm

Abstract

To estimate acoustic impedance and porosity in inter-well regions, a seismic inversion based on Hooke and Jeeves’ methods has been developed. The Hooke and Jeeves algorithm is a local optimization method that can reach a local or global optimum solution depending on the starting model. To prevent convergence to a local optimum, in the present study, the solution is constrained by well-log data. To optimize parameters, the algorithms are first assessed on synthetic data followed by the coal coking and wedge model. The algorithm’s performance is very satisfactory, according to the error analysis between the inverted and anticipated outcomes. Further, a real data application from the Blackfoot field, Canada, has been performed in two steps: First, a composite seismic trace close to the well location is retrieved, inverted into an impedance, and compared with the well-log impedance. The analysis shows how well the well-log impedance corresponds to the inverted impedance. Finally, in the second step, the entire seismic reflection data is subjected to the Hooke and Jeeves–based inversion, and the volume of acoustic impedance and porosity in the inter-well region is predicted. The paper demonstrates that when local optimization is utilized and is constrained by well-log data, the algorithms yield higher-resolution subsurface information. A low impedance anomaly (ranging from 7000 to 9500 m/s g/cc) was detected between 1040 and 1060 ms of two-way travel time, according to the study of inverted impedance. Additionally, the same zone contains an estimated high porosity anomaly (> 12%) that is thought to be a sand channel/reservoir. According to the results of this study, it is possible to swiftly and affordably assess subsurface parameters like acoustic impedance and porosity using seismic inversion based on the Hooke and Jeeves technique.