Challenge: Drill two 8½-in sections though interbedded formations in Egypt’s Western Desert in the fewest trips while maintaining borehole quality and verticality.

Solution: Run a Neyrfor™ turbodrilling system with the 8½-in Kinetic™ diamond-impregnated bits in the first and second sections.

Results: Neyrfor system and the Kinetic bits averaged 8.8 ft/h to TD in their respective sections, drilling 2,340 ft in the first run: the longest section drilled in Africa by an 8½-in diamond-impregnated bit. The combined runs saved three weeks of rig time.

High-ROP turbodrilling with drillbit durability required

An operator working in the Yidma/Alamein Field in Egypt's Western Desert was trying to complete two 8½-in hole sections through interbedded sandstone and shales of the Alam El Bueib (AEB) and the sandstone-shale-limestone of the Khatatba Formation. Results were marked by short-run lengths and low ROPs—produced by tungsten carbide insert (TCI) bits—forcing numerous unplanned trips. Additionally, another manufacture's high-speed motor was lost downhole, which put the operation 19 days behind schedule. Going forward, the operator wanted to minimize the number of trips to section TD, while maintaining verticality and wellbore quality in each.

For the first run, the BHA consisted of a 6⅝-in TSXL Neyrfor turbodrilling system and Smith Bits 8½-in K503 Kinetic diamond-impregnated bit. The bit profile called for initially drilling with low weight on bit (WOB); parameters were then increased to full drilling rate. Maximum penetration rate was sustained with excellent ROP through the AEB Formation to 14,065 ft. The drillstring was pulled out of hole (POOH) to inside the casing shoe for pump repairs. The assembly was run back to bottom and drilled through the AEB and Khatatba Formations to 16,067 ft; an ROP of 8.8 ft/h was maintained totaling 2,340 ft drilled.

For the second run, a second Neyrfor turbodrilling system and 8½-in K507 Kinetic bit were made up and RIH to shoe. Adhering to the bit profile requirements, drilling was once again started with low WOB and then increased to full drilling parameters. The Khatatba Formation was drilled from 16,067 ft to TD of 17,000 ft at a penetration rate of 8.72 ft/h, totaling 933 ft drilled.

Operator saves 3 weeks of rig time

A Neyrfor turbodrilling system with a K503 Kinetic bit drilled 2,340 ft at 8.8 ft/h to the logging point; this set a record for footage drilled in Africa by a single 8½-in diamond-impregnated drill bit. After wireline logging was completed, a new Neyrfor turbodrilling system and K507 bit drilled another 933 ft at 8.7 ft/h to well TD. This operation eliminated an estimated 12 TCI bit runs, saving the operator at least 3 weeks of rig time.

Neyrfor turbodrilling systems provide consistent, predictable drilling rates for directional and horizontal turbodrilling applications. Neyrfor systems have exceptional toolface control, ensuring that directional objectives can be achieved in even the most demanding environments.

In comparison with positive displacement motors (PDMs), Neyrfor turbodrilling systems offer

• energy efficiency
• power output
• reliability and operating life
• vibration migration
• high-pressure, high-temperature (HPHT) capabilities
• directional and underbalanced drilling capabilities
• improved borehole quality.

Kinetic diamond-impregnated bits are designed for hard, abrasive formations and use application-specific materials to withstand the most rigorous drilling conditions. They are capable of drilling out float equipment yet equally effective when softer formations are encountered.

To optimize durability and ROP bits are built with

• grit hot-pressured inserts
• polycrystalline diamond compact (PDC) cutters
• thermally stable polycrystalline diamonds
• diamond-impregnated matrix materials.