FMI Formation Microimager - High Resolution Solution Tool to Reveal Structural Complexity, Western Desert, Egypt

Abstract

The Formation Micro Imager tool provides high resolution electrical images, which is capable of<br>detecting any features within the studied formation. In majority of cases, FMI can replace an expensive<br>coring cost depending on the finer scale details identified beside image contrast and extended borehole coverage.<br>A very well known oil company in Egypt is drilling in Western Desert province with high profile drilling<br>program, almost 10 wells per month, and as all the structural complexity is being solved by their high<br>resolution seismic sections, hardly any problem or well misplacing they faced before. This is before<br>they drill one of their development wells, in which they encountered a very unusual section; where all<br>the supplementary data and the conventional open hole logs beside ditch cutting and microscopic<br>examination didn’t reveal any fair solution to them.<br>FMI images were kept as their last chance trying to understand how this dilemma could be solved. FMI<br>overall image quality was very good, which contributed efficiently to the structural interpretation<br>results. The processed FMI* image showed strong and distinctive evidence for the severe cataclastic<br>deformation, rocks breakage, fractures and brecciation owing to the crushing and pulverization<br>processes along the sub- seismic faults planes cutting through the studied formation.<br>The studied well is vertical over the entire logged interval, hence penetrated the investigated zone<br>parallel to two (sub-vertical) main cross-cutting faults; therefore the well was penetrating through the<br>breccia zone along the fault plane for a considerable distance. This resulted in a great thickness, about<br>30 m, which was imaged over that fault breccia zone.<br>FMI was the only tool capable of solving this structural complexity and mixed lithology that were never<br>been solved unless cored, and hence increasing the well capital expenditures as compared to a single FMI run.