Presenter
Brigido Vicuña from Halliburton
Co-authors
Andrew McGill, Equinor
Abstract
3rd Geosteering Workshop by NORCE and NFES 2024 11-13 November 2024
• Technical topic: Advancement in Ultra Deep Azimuthal Resistivity (UDAR) Technology and Interpretation. New Inversion Algorithms
Title: New UDAR Inversion Techniques for improved Imaging of Geological Structures
Authors: Brigido Vicuña, Halliburton, and Andrew McGill, Equinor.
- Objectives/Scope: Please list the objectives and/or scope of the proposed paper.
Physical UDAR tool development focuses on obtaining improved UDAR measurements with higher signal to noise ratio (SNR) and stronger signal strength. In addition to this the industry is simultaneously focusing on the development of superior imaging techniques using existing tool designs through updated inversion algorithms. The evaluation of new algorithms for an existing UDAR tool is applied in a well that was drilled in the Snorre field with the goal of geostopping against the Inner Snorre Fault (IFS). These results are compared to other well previously drilled in the area where the detection of the fault was very uncertain to demonstrate the importance of continually improving inversion algorithms.
- Methods, Procedures, Process: Briefly explain your overall approach, including your methods, procedures and process.
During execution of the well, an existing point-by-point one dimensional deterministic inversion approach was implemented to define the ISF plane prior to its intersection, which resulted in a successful geostopping operation. The inversion result, although sufficient to meet the wells objectives, displayed intervals of high misfit, analysis of the UDAR Azimuthal Resistivity and Geosignal images revealed a 3D geological structure as the well approached the ISF. This complex geology led to small scale artifacts in the inversion which degraded imaging of the surrounding geology. A new inversion algorithm based on slope-log and square log models in combination with improved signal processing was applied to improve the imaging of the ISF, based on the RT data.
- Results, Observations, Conclusions: Please describe the results, observations and conclusions of the proposed paper.
The case study shows that advanced signal processing in combination with superior inversion algorithms can produce improvements in inversion models even without improvements to the hardware. The results from the new 1D inversion were less sensitive to the lateral changes in the resistivity boundaries and produced a clearer and more reliable result. These improvements produced better imaging of the ISF which would in future wells improve the decision-making process in such challenging settings and provides improved reservoir understanding from the improved estimation of the apparent dip of the fault plane.
- Novel/Additive Information: Please explain how this paper will present novel (new) or additive information to the existing body of literature that can be of benefit to and/or add to the state of knowledge in the petroleum industry.
Continued development of UDAR inversion imaging techniques provides tools that can be used to both reexamine wells drilled previously but also improve the decision making in future wells. The impact on geological imaging results in a reduction in the uncertainty when drilling in complex environments and simplification of the geosteering decision making process.
Biography
Brígido Vicuña is the Geosteering Lead at Halliburton, based in Norway. Vicuña joined the oil and gas industry in 2012 as an MLWD field engineer. He began his career with Halliburton in 2014 as a geosteering geologist in Venezuela and later moved to Houston in 2019 to support global geosteering operations focusing on ultradeep resistivity. In 2020, Vicuña began working as a Geosteering Tecnical Advisor in Norway and later moved to his present. He holds a bachelor’s degree in geological engineering from the Universidad de Oriente of Venezuela.