Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate

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Bottom hole assembly (BHA) designs were assessed in field trials for their ability to achieve critical low inclination requirements, while simultaneously enabling high drill rates. Because angle has historically been controlled by reducing weight on bit (WOB), these are often competing priorities. The use of real time surveillance of mechanical specific energy (MSE) provided unique insights into the bit dysfunction that occurs with many practices used to control angle. These quantitative insights supported the development of BHA and operating practices that maintained low angle while also achieving major gains in drilling performance.

The McGinness Hills field in Lander County Nevada is a geothermal operation with wells drilled in hard metamorphic and crystalline formations. Wellbore inclinations must be maintained below 2.0 degrees in the critical 20 inch interval in order to allow use of lineshaft pumps, which is challenging in the required hole sizes and rock hardness. Formation strengths are similar to petroleum operations in the Rockies and West Texas.

Pendulum and packed-hole assemblies were tested, and straight motors and slick assemblies were used for corrections. Well build rates were assumed to be controlled by the three-point curvature in the lower assembly and stabilizer placement was modified to control this curvature. The effectiveness of the curvature control as WOB was increased was evaluated from inclination measurements. Real time MSE analysis was used to manage bit operating performance and to determine the root causes of bit dysfunction.

The results demonstrated that packed-hole assemblies could be designed that controlled inclination while enabling 2-3 times higher WOB, and that the use of pendulum assemblies should be eliminated. Packed assemblies drilled 87% faster. The increased WOB resulted in higher drill rates, major reduction in whirl and extended bit life, which are equally important performance objectives in hard rock drilling. The use of MSE surveillance allowed the physical processes to be understood deterministically, so that the philosophical design principles can be applied in other petroleum and geothermal operations.

Citation Formats

Sandia National Laboratories. (2014). Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate [data set]. Retrieved from https://gdr.openei.org/submissions/433.
Export Citation to RIS
Knudsen, Steven D., Dupriest, Fred, Zemach, Ezra, and Blankenship, Douglas A. Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate. United States: N.p., 30 Apr, 2014. Web. https://gdr.openei.org/submissions/433.
Knudsen, Steven D., Dupriest, Fred, Zemach, Ezra, & Blankenship, Douglas A. Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate. United States. https://gdr.openei.org/submissions/433
Knudsen, Steven D., Dupriest, Fred, Zemach, Ezra, and Blankenship, Douglas A. 2014. "Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate". United States. https://gdr.openei.org/submissions/433.
@div{oedi_433, title = {Practices Maintain Straight Hole in Crooked Hole Conditions, While Also Enabling Significant Gains in Drill Rate}, author = {Knudsen, Steven D., Dupriest, Fred, Zemach, Ezra, and Blankenship, Douglas A.}, abstractNote = {Bottom hole assembly (BHA) designs were assessed in field trials for their ability to achieve critical low inclination requirements, while simultaneously enabling high drill rates. Because angle has historically been controlled by reducing weight on bit (WOB), these are often competing priorities. The use of real time surveillance of mechanical specific energy (MSE) provided unique insights into the bit dysfunction that occurs with many practices used to control angle. These quantitative insights supported the development of BHA and operating practices that maintained low angle while also achieving major gains in drilling performance.

The McGinness Hills field in Lander County Nevada is a geothermal operation with wells drilled in hard metamorphic and crystalline formations. Wellbore inclinations must be maintained below 2.0 degrees in the critical 20 inch interval in order to allow use of lineshaft pumps, which is challenging in the required hole sizes and rock hardness. Formation strengths are similar to petroleum operations in the Rockies and West Texas.

Pendulum and packed-hole assemblies were tested, and straight motors and slick assemblies were used for corrections. Well build rates were assumed to be controlled by the three-point curvature in the lower assembly and stabilizer placement was modified to control this curvature. The effectiveness of the curvature control as WOB was increased was evaluated from inclination measurements. Real time MSE analysis was used to manage bit operating performance and to determine the root causes of bit dysfunction.

The results demonstrated that packed-hole assemblies could be designed that controlled inclination while enabling 2-3 times higher WOB, and that the use of pendulum assemblies should be eliminated. Packed assemblies drilled 87% faster. The increased WOB resulted in higher drill rates, major reduction in whirl and extended bit life, which are equally important performance objectives in hard rock drilling. The use of MSE surveillance allowed the physical processes to be understood deterministically, so that the philosophical design principles can be applied in other petroleum and geothermal operations.
}, doi = {}, url = {https://gdr.openei.org/submissions/433}, journal = {}, number = , volume = , place = {United States}, year = {2014}, month = {04}}

Details

Data from Apr 30, 2014

Last updated May 20, 2024

Submitted Aug 27, 2014

Organization

Sandia National Laboratories

Contact

Steven Knudsen

505.844.7306

Authors

Steven D. Knudsen

Sandia National Laboratories

Fred Dupriest

Texas AM University

Ezra Zemach

Ormat Nevada Inc

Douglas A. Blankenship

Sandia National Laboratories

DOE Project Details

Project Lead Eric Hass

Project Number FY14 AOP 3.6.1.3

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