The drilling of horizontal wells in complex reservoirs is progressively increased in the last years forcing a speed up of the logging while drilling (LWD) technology development. This common trend allows to strongly increase the knowledge and the experience of the technology highlighting the limitations and the potentiality as it already well known for the wireline logging (WL) technology.
The illustrated example (South Italy) shows how the acquired knowledge and the defined reliability of the logging while drilling technology can be applied in an horizontal well drilled into tight and fractured carbonate reservoir to identify and quantify the best fluid path.
Economic and HSE aspects have been strongly considered to identify an appropriate final workflow.
The proposed case history is the first Eni example applying such technique.
The confidence in the proposed approach comes from an accurate comparison between the wireline and while drilling logs response both available along a portion of the analyzed well section.
The workflow applied to this while drilling suite was calibrated to obtain a coherent formation evaluation, based on the capability of LWD technology to capture the different scale of phenomena occurring into fractured reservoirs.
The integrated analysis of sonic and electric image while drilling logs provided the essential information to quantify the matrix and the fractured porosity as well as the "mixed" porosity, and fundamental data to illuminate the reservoir where TLC logging cannot get through.
In addition open fractures (compared with mud absorption, Gas While Drilling and temperature profile) have been recognized defining the most producible intervals.
Thanks to the combination of technology, knowledge and people the case study it's a clear example how well data acquisition can be conducted safely and with significant saving (50 hours of operating time) pointing out the VOI that in this specific case contributed to the optimal well completion been able to deliver 900 + bopd.
