Reapplying rod grease in highly fractured well

Highly fractured formations with clay faults in the Zacatecas region of central Mexico can pose drilling challenges, including lost mud returns and associated drilling complications that can increase costs. An operator was drilling in the area with a drilling mud that invaded the large fractures at 755-ft [230-m] MD, causing torque to increase from the ensuing friction between the drilling rods and the formation. Torque increased above 4,000 psi [27.6 MPa], and drillpipe began to excessively vibrate.

The operator sought a rod grease that would allow drilling at torque levels below 3,000 psi to avoid protracted drilling interruptions. The operator also needed to ensure that the grease would adhere to wet rods during drilling to avoid pulling out of hole (POOH) repeatedly to regrease the rods.

Using ROD COAT L 1000 rod grease to improve torque, avoid repeated reapplications

For mitigating increased torque, M-I SWACO recommended ROD COAT L 1000 rod grease, which includes properties that boost adherence and minimize drillstring vibration. The grease provides an extremely tacky formula for excellent adhesion to rods, even if the rods are wet. Its bright orange color makes it highly visible, allowing operators to see the grease's adherence to the rods. In addition, the barium-free grease is based upon lithium technology, making it more environmentally friendly compared with conventional products.

Cutting costs by 29% with improved grease adherence

After drilling and POOH, a substantial quantity of grease continued to adhere to the rods. Because of its lubricating characteristics, the grease decreased drillstring vibration. Torque declined from 4,000 psi to 2,800 psi [19.3 MPa] after applying the ROD COAT L 1000 rod grease. This allowed the customer to achieve the required depth of 1,903 ft [580 m] on time.

Because the rodstring did not have to be tripped again for regreasing at the end of each shift as was previously required, the customer decreased rig time, reduced expenses by 29%, and saved USD 1,265.97 per wellbore.