Enhanced Borehole Imaging Through Advanced Digital Real Time Solutions

Abstract Borehole imaging has been a cornerstone for high-resolution geological, petrophysical and geomechanical interpretation for several decades and development of new logging-while-drilling (LWD) borehole imaging technologies have enabled real time decisions for operational and economic efficiency. This paper looks at the challenges posed by higher drilling rates and provides a technology solution for high-definition real time borehole images incorporating electronics and digital innovations. This paper will also discuss the integration borehole imaging with other disciplines to provide a richer interpretation of the data sets. Higher rate of penetration (ROP) often is considered a limiting factor for high-resolution borehole imaging. However, a unique design of the LWD imager with improved electronics have overcome this challenge where an eight-button ultra-high resolution sleeve design with 2 rows of axially offset sensors provide enough data redundancy for borehole wall features without compromising on the feature integrity. A new downhole image compression driven by machine learning was incorporated to enable real time high-definition image data at surface. The results presented in this paper discuss the feature-integrity and high-definition borehole imaging at high drilling rates. The implemented image compression allowed for high quality images in real time that allowed full interpretation of the structural and stratigraphic features present in carbonate reservoirs. Real time images were acquired with ROP ranging from 160- ft/h to 280 ft/h proving that the acquisition of high-quality images is not a limiting factor in operational efficiency. The acquired images provided a vast array of detailed geological, petrophysical and geomechanical observations in such conditions that were not previously possible due to technology limitations. The high resolution of LWD images allows for several advanced answer products that will be discussed in this paper, such as secondary porosity calculation in vuggy carbonates, fracture analysis, structural and stratigraphic interpretation. This paper also explores the benefits of ultra-high resolution imaging integration with bed boundary mapping results to identify of possible water corridors to optimize completion design, input into formation pressure while drilling program design by determining the best the probe orientation, and integration with nuclear magnetic resonance for facies typing. This new approach builds on the learnings from previous experience and unique design of sensors to provide solutions and efficiencies that have always been sought from borehole imaging technology. The availability of real time high-definition images in challenging logging conditions with redesigned image compression provides real time solutions.