蘑菇传媒

Borehole images have been a trusted companion of geoscientists since the technology became available a few decades ago. The image logs have been on a journey of their own, from different physics of measurements to different conveyance methods across different resolutions. Their application in geology, geomechanics, petrophysics and well-operations have increased only with time. With advances in logging while drilling (LWD) technologies, the spectrum of application has grown larger. This work presents a completely new measurement that creates borehole images at the bit, with sensors embedded in the bit-design to provide the first-ever formation imaging as the well gets drilled.

LWD images are usually placed tens of feet away from the drill-bit based on the drilling bottom hole assembly (BHA) design and can get impacted by the onset of breakout or washout before the formation gets imaged, also the mud losses can jeopardize formation imaging. Often drilling large hole-size sections, before entering the reservoir interval, can miss out on characterizing any event of geological significance. There are technology limitations over the mud type, hole size and

The initial results of at-bit imaging are encouraging, as observed in the assessment of various geological facies in a Middle East carbonate reservoir. The high-resolution imager was able to identify subtle geological features like fractures, vugs, stylolites, trace fossils etc that matches with known reservoir properties from offset wells. The advantage this technology brings is also in the fact that it does not require any changes in drilling parameters, any slow-down of ROP or any additional instructions for drillers and it represents a full safety-compliant technique. This first of its kind technology at the bit with very high-resolution imaging can prove to be a game-changer with possible applications in the intervals not often characterized.