Abstract:

With a challenging horizontal well placement, especially in complex structure fields. To guarantee the success of drilling horizontal wells, new technologies must be used to reduce structural uncertainty and achieve high net-to-gross in the horizontal section for superior production.

Petrobel (ENI), decided to drill a horizontal well in the Belayim Field Area, Where a complex structural system with highly uncertainty takes place. The main source of structural uncertainty resides in the poor quality of seismic data from which reservoir models are created. In addition to the uncertainty in the fault/horizon positions due to the poor resolution of seismic images, structural interpretations or migration results themselves are not unique and often rely on the subjective decision of an expert.

The placing of horizontal wells presented significant challenge, as the objective was to maximize reservoir exposure, taking into account high structural uncertainty with lateral variation in formation dips. Based on the well plan path, pre-job modelling with a resistivity inversion indicated a lot of geosteering difficulties and challenges

As a fit for purpose, solution to address these challenges a new geo-steering tool was selected utilizing a new stochastic resistivity inversion, which would be able to map multiple bed boundaries in high resolution, in order to illuminate the reservoir structure in real time ahead of the bit. Which would significantly improve geosteering decisions to remain within the oil-bearing sand.

While drilling the well, unexpected geological features were encountered, however the new mapping technology while drilling service could provide the team with the necessary information to geosteer into the target, and expose the well to around 100 meters of clean sand. Inside the reservoir. The new stochastic inversion technology was able to detect Thin layers about 0.5m in thickness, were observed about 1.5m TVD below the well trajectory, in addition to mapping the Water contact which was confirmed to be at TVD 2398m. Updating the model for this area with the water contact exact depth will play a crucial role in future wells planning for in Belayim Field

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