Abstract

The expansion of the heavy oil recovery campaign in Venezuela led by the National Oil Company and its partner has placed more attention on developing shallow reservoirs in the Orinoco Oil Belt. Here, the main challenge is to economically drill horizontal shallow wells at less than 1300 ft TVD, and with more than 5000 ft of lateral extension. To reach these reservoirs, the well path is normally planned with high build rates in the intermediate phase reaching ≥9°/100 ft before and after the tangent section that is required to place the pumping system.

When drilling using a mud motor, the high build rates planned for the intermediate section can result in even higher localized dogleg severities (DLS) as drilling switches between sliding and rotating. This creates several problems when drilling and completing the horizontal section, for example, poor transfer weight to the bit while sliding and torque and drag situations, which can make it impossible to reach the entire horizontal section planned with this BHA.

Progressive cavity pumps (PCPs) are preferred for use in the Orinoco Oil Belt as they are more efficient and economical. However, high dogleg severities are not recommended for production systems using PCPs. Most PCP designers recommend placing the equipment at doglegs of <7°/100 ft to increase service life and avoid premature intervention due to excessive wear.

To optimize design and extend the life of production equipment, a new mechanical well design was developed where the deviation of the hole starts in the 16-in. top hole using a directional BHA configuration with a mud motor. This configuration drilled successfully and safely; making possible to reach the entire planned horizontal section and complete it with an optimum production system.

By applying this new design and using conventional directional technologies, it is possible to drill the entire horizontal section and use the same completion system used in the rest of the area. This is an important cost savings because the custom directional technology can be used to reach the entire horizontal section but completion maintenance costs won't increase. In addition, we avoid deferred production costs due to shutting down the wells.

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