PEMEX was developing a horizontal well in a field near Villahermosa, Mexico, and needed to drill a curve in the 12¼-in section. The drilling plan called for a curve with a 78° inclination and 28°—22° azimuth to allow the well to be landed in the Paleocene reservoir. Adding to the challenge of developing this well, the field is characterized by high shock and vibration and a narrow mud weight window. Wells drilled in this field require heavy mud weight (greater than 14 ppg) to remain within the reservoir's mud weight window. Maintaining this window is critical to avoiding gains or losses that result in NPT.
To achieve its objectives, PEMEX needed an RSS capable of building 5°/30 m [5°/100 ft] to assure it could achieve the planned 3.6°/30 m [3.6°/100 ft] build. It would also need to be able to operate reliably in heavy mud weight conditions, which typically present reliability and durability issues for conventional RSSs.
SLB drilled curve and maintained reliability in heavy mud weight environment with PowerDrive Orbit™ rotary steerable system. We paired RSS with a SHARC™ high-abrasion-resistance PDC drill bit to control shock and vibration, as modeled by IDEAS™ integrated dynamic design and analysis platform.
We precisely steered curve with an average dogleg severity of 3.6°/30 m [3.6°/100ft] in a large hole section, successfully drilled section to TD in heavy mud weight conditions, and saved 5.6 days of drilling time, reducing operating costs by USD 300,000.
SLB experts recommended the PowerDrive Orbit RSS, which has a pad actuation with metal-to-metal seals that withstand solids in the mud. Using the IDEAS platform to model bit-rock interaction specific to the field, SLB determined that the SHARC bit would effectively manage shock and vibration in combination with the highly reliable push-the-bit RSS.
The PowerDrive Orbit RSS smoothly drilled the 12¼-in section from shoe to shoe with an average dogleg severity of 3.6°/100 ft [3.6°/30 m], allowing the well to be landed on target. The RSS and SHARC bit reached section TD 5.6 days ahead of schedule by withstanding heavy mud weight conditions and effectively managing shock and vibration. This time savings reduced operating costs by USD 300,000.
PEMEX plans to use these technologies to more efficiently develop future horizontal wells, which are the trajectory type with the highest recovery rate in the field. For this field, a typical horizontal well produces about 4,000 bbl/d with gas lift—1,500 bbl/d more than other types of directional wells typically produce there.
