Abstract

The changes of the recent years on the oil market motivated the collaboration between operators and service companies to find cost viable solutions to optimize production. This involved also an increase of horizontal wells in complex reservoir with advanced technology. This solution was employed by Petrobel to drill a challenging horizontal well in Belayim Area. This is a structural complex area, result of the interference of two main extensional faults systems related to the opening of the Gulf of Suez. The well area was interpreted from seismic to be an anticline structure elongated in NNW/SSE parallel to a regional fault dipping westward and limiting the field. The traditional approach to drill horizontal wells on this type of field would have been to assess the structure and target with a pilot hole. To eliminate the need for a pilot hole and improve financial sustainability, Petrobel and Schlumberger applied technologies that are utilized in real-time for pilot hole elimination and moreover to define the multiple boundaries inside or around the target. The objective was to map the structure far away from the borehole, opening the possibility of taking proactive decisions on wellbore trajectory to land and keep the wellbore within the desired oil bearing sand. The solution was introduced for the first time in Egypt by Petrobel. Different technologies were combined to provide multiple depths of investigation, from the reservoir scale to the proximal area around the wellbore. The set-up allowed to land the well using the reservoir mapping data despite a completely unexpected geological scenario. Once entered the target, a detailed description of the oil bearing sand was possible using the inversion based on the multilayer bed boundary detection service information. The innovative approach allowed geosteering the subject well within 100 m Measured depth of clean sand despite abrupt structural changes not visible on pre-drill seismic model. Inside the reservoir, the advanced high-resolution inversion (Periscope HD) was selected to be run, In order to optimize the position of the well in the target, the tool was able to map multiple bed boundaries in high resolution, in order to illuminate the reservoir structure in real time ahead of the bit. Thin layers, about 0.5m in thickness, were observed 25m MD ahead of the bit about 1.5m TVD below the well trajectory, which improve geosteering decisions to remain within the oil-bearing sand. Also, the PeriScopeHD was able to map the Water contact.

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