Search NASA⌕ Search

SEARCH · Search NASA

Results for “drill bit”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Experimental Investigation of Drillstring Torsional Vibration Effect on Rate of Penetration with PDC Bits in Hard Rock

Polycrystalline diamond compact (PDC) bits have shown tremendous performance compared to roller cone bits and have gained attraction in deep geothermal drilling applications. While PDC bits can reach a higher rate of penetration compared to other bits, they are more prone to drilling vibrations. The scope of this paper is to quantify the effects of drillstring torsional vibrations on PDC bit performance using a laboratory testing facility. Here, the tests were performed with three drillstring configurations to evaluate the effect of drillstring vibrations. The results showed that rigid testing overestimates the bit rate of penetration by 35% due to torsional vibrations.

15 GEOTHERMAL ENERGY↗
DOE OSTI2021

A Modular Mechanism for Downhole Weight-on-Bit and Torque Reaction in Small Diameter Boreholes

Drilling systems that use downhole rotation must react torque either through the drill-string or near the motor to achieve effective drilling performance. Problems with drill-string loading such as buckling, friction, and twist become more severe as hole diameter decreases. Therefore, for small holes, reacting torque downhole without interfering with the application of weight-on-bit, is preferred. In this paper, we present a novel mechanism that enables effective and controllable downhole weight on bit transmission and torque reaction. This scalable design achieves its unique performance through four key features: (1) mechanical advantage based on geometry, (2) direction dependent behavior using rolling and sliding contact, (3) modular scalability by combining modules in series, and (4) torque reaction and weight on bit that are proportional to applied axial force. As a result, simple mechanical devices can be used to react large torques while allowing controlled force to be transmitted to the drill bit. We outline our design, provide theoretical predictions of performance, and validate the results using full-scale testing. The experimental results include laboratory studies as well as limited field testing using a percussive hammer. These results demonstrate effective torque reaction, axial force transmission, favorable scaling with multiple modules, and predictable performance that is proportional to applied force.

15 GEOTHERMAL ENERGY↗
NASA NTRS1980

Drill-motor holding fixture

Guide improves accuracy and reduces likelihood of bit breakage in drilling large work pieces. Drill motor is mounted on pipe that slides on furniture clamp. Drill is driven into work piece by turning furniture-clamp handle.

Chartier, E. N.↗
NASA NTRS2010

Ultrasonic/Sonic Rotary-Hammer Drills

Ultrasonic/sonic rotary-hammer drill (USRoHD) is a recent addition to the collection of apparatuses based on ultrasonic/sonic drill corer (USDC). As described below, the USRoHD has several features, not present in a basic USDC, that increase efficiency and provide some redundancy against partial failure. USDCs and related apparatuses were conceived for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. They have been described in numerous previous NASA Tech Briefs articles. To recapitulate: A USDC can be characterized as a lightweight, lowpower, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. A basic USDC includes a piezoelectric stack, an ultrasonic transducer horn connected to the stack, a free mass ( free in the sense that it can bounce axially a short distance between hard stops on the horn and the bit), and a tool bit. The piezoelectric stack creates ultrasonic vibrations that are mechanically amplified by the horn. The bouncing of the free mass between the hard stops generates the sonic vibrations. The combination of ultrasonic and sonic vibrations gives rise to a hammering action (and a resulting chiseling action at the tip of the tool bit) that is more effective for drilling than is the microhammering action of ultrasonic vibrations alone. The hammering and chiseling actions are so effective that unlike in conventional twist drilling, little applied axial force is needed to make the apparatus advance into the material of interest. There are numerous potential applications for USDCs and related apparatuses in geological exploration on Earth and on remote planets. In early USDC experiments, it was observed that accumulation of cuttings in a drilled hole causes the rate of penetration of the USDC to decrease steeply with depth, and that the rate of penetration can be increased by removing the cuttings. The USRoHD concept provides for removal of cuttings in the same manner as that of a twist drill: An USRoHD includes a USDC and a motor with gearhead (see figure). The USDC provides the bit hammering and the motor provides the bit rotation. Like a twist drill bit, the shank of the tool bit of the USRoHD is fluted. As in the operation of a twist drill, the rotation of the fluted drill bit removes cuttings from the drilled hole. The USRoHD tool bit is tipped with a replaceable crown having cutting teeth on its front surface. The teeth are shaped to promote fracturing of the rock face through a combination of hammering and rotation of the tool bit. Helical channels on the outer cylindrical surface of the crown serve as a continuation of the fluted surface of the shank, helping to remove cuttings. In the event of a failure of the USDC, the USRoHD can continue to operate with reduced efficiency as a twist drill. Similarly, in the event of a failure of the gearmotor, the USRoHD can continue to operate with reduced efficiency as a USDC.

Badescu, Mircea↗
NASA NTRS2000

Percussive Force Magnitude in Permafrost

An in-depth look at percussive drilling shows that the transmission efficiency is very important; however, data for percussive drilling in hard rock or permafrost is rarely available or the existing data are very old. Transmission efficiency can be used as a measurement of the transmission of the energy in the piston to the drill steel or bit and from the bit to the rock. Having a plane and centralized impact of the piston on the drill steel can optimize the transmission efficiency from the piston to the drill steel. A transmission efficiency of near 100% between piston and drill steel is possible. The transmission efficiency between bit and rock is dependent upon the interaction within the entire system. The main factors influencing this transmission efficiency are the contact area between cutting structure and surrounding rock (energy loss due to friction heat), damping characteristics of the surrounding rock (energy dampening), and cuttings transport. Some of these parameters are not controllable. To solve the existing void regarding available drilling data, an experiment for gathering energy data in permafrost for percussive drilling was designed. Fifteen artificial permafrost samples were prepared. The samples differed in the grain size distribution to observe a possible influence of the grain size distribution on the drilling performance. The samples were then manually penetrated (with a sledge-hammer) with two different spikes.

Eustes, A. W., III↗
DOE OSTI2024

2024 Geothermal Rising Conference Poster

As part of a U.S. DOE Geothermal Technologies Office funding opportunity, Geysers Power Company, LLC, an indirect subsidiary of Calpine Corporation, partnered with Sandia National Labs, EGI at the University of Utah, and Texas A&M University to demonstrate increased drilling performance at The Geysers Geothermal Field. The performance target in the drilling demonstrations is at least a 25% improvement in rates of penetration with increased time on bottom for each bit. The planned drilling demonstrations are being conducted as part of an existing drilling campaign intended to enhance reservoir utilization. A major goal of the project is to assess the effectiveness of implementing mechanical specific energy (MSE) and drilling dysfunction diagnosis and remediation in these challenging environments, as well as alternate bit technologies. The first demonstration well has been completed, with a total of 15 PDC bit runs in the 17.5”, 12.25” and 8.5” sections. Initial analysis shows ROP gains in all three hole sections, especially in the 17.5” and 12.25” sections, compared with conventional roller cone bit runs in the demonstration well and offset wells. However in the 8.5” hole, wear and damage to the PDC bits resulted in relatively short bit runs. Analysis is underway to take advantage of the positive results and remediate the challenges.

15 GEOTHERMAL ENERGY↗
DOE OSTI2021

Evaluation of Microhole Drilling Technology for Geothermal Exploration, Assessment, And Monitoring

One of the greatest barriers to geothermal energy expansion is the high cost of drilling during exploration, assessment, and monitoring. Microhole drilling technology—small-diameter 2–4 in. (~5.1–10.2 cm) boreholes—is one potential low-cost alternative for monitoring and evaluating bores. However, delivering high weight-on-bit (WOB), high torque rotational horsepower to a conventional drill bit does not scale down to the hole sizes needed to realize the cost savings. Coiled tube drilling technology is one solution, but these systems are limited by the torque resistance of the coil system, helical buckling in compression, and most of all, WOB management. The evaluation presented herein will: (i) evaluate the technical and economic feasibility of low WOB technologies (specifically, a percussive hammer and a laser-mechanical system), (ii) develop downhole rotational solutions for low WOB drilling, (iii) provide specifications for a low WOB microhole drilling system, (iv) implement WOB control for low WOB drilling, and (v) evaluate and test low WOB drilling technologies.

15 GEOTHERMAL ENERGY↗
DOE OSTI2023

Downhole Sensing and Event-Driven Sensor Fusion for Depth-of-Cut Based Autonomous Fault Response and Drilling Optimization

Achieving robust and efficient drilling is a critical part of reducing the cost of geothermal energy exploration and extraction. Drilling performance is often evaluated using one or more of three key metrics: depth of cut (DOC), rate of penetration (ROP), and mechanical specific energy (MSE). All three of these quantities are related to each other. DOC refers to the depth a bit penetrates into rock during drilling. This is an important quantity for estimating bit behavior. ROP is the simply the DOC multiplied by the rotational rate, and represents how quickly the drill bit is advancing through the ground. ROP is often the parameter used for drilling control and optimization. Finally, MSE provides insight into drilling efficiency and rock type. MSE calculations rely on ROP, drilling force, and drilling torque. Surface-based sensors at the top of the drill are often used to measure all these quantities. However, top-hole measurements can deviate substantially from the behavior at the bit due to lag, vibrations, and friction. Therefore, relying only on top-hole information can lead to suboptimal drilling control. In this work, we describe recent progress towards estimating ROP, DOC, and MSE using down-hole sensing. We assume down-hole measurements of torque, weight-on-bit (WOB). Our hypothesis is that these measurements can provide more rapid and accurate measures of drilling performance. We show how a multi-layer perceptron (MLP) machine learning algorithm can provide rapid and accurate performance when evaluated on experimental data taken from Sandia’s Hard Rock Drilling Facility. In addition, we implement our algorithms on an embedded system intended to emulate a bottom-hole-assembly for sensing and estimation. Our experimental results show that DOC can be estimated accurately and in real-time. These estimates when combined with measurements for rotary speed, torque, and force can provide improved estimates for ROP and MSE. These results have the potential to enable better drilling assessment, improved control, and extended component lifetimes.

15 GEOTHERMAL ENERGY↗
NASA NTRS2013

Acquisition and Retaining Granular Samples via a Rotating Coring Bit

This device takes advantage of the centrifugal forces that are generated when a coring bit is rotated, and a granular sample is entered into the bit while it is spinning, making it adhere to the internal wall of the bit, where it compacts itself into the wall of the bit. The bit can be specially designed to increase the effectiveness of regolith capturing while turning and penetrating the subsurface. The bit teeth can be oriented such that they direct the regolith toward the bit axis during the rotation of the bit. The bit can be designed with an internal flute that directs the regolith upward inside the bit. The use of both the teeth and flute can be implemented in the same bit. The bit can also be designed with an internal spiral into which the various particles wedge. In another implementation, the bit can be designed to collect regolith primarily from a specific depth. For that implementation, the bit can be designed such that when turning one way, the teeth guide the regolith outward of the bit and when turning in the opposite direction, the teeth will guide the regolith inward into the bit internal section. This mechanism can be implemented with or without an internal flute. The device is based on the use of a spinning coring bit (hollow interior) as a means of retaining granular sample, and the acquisition is done by inserting the bit into the subsurface of a regolith, soil, or powder. To demonstrate the concept, a commercial drill and a coring bit were used. The bit was turned and inserted into the soil that was contained in a bucket. While spinning the bit (at speeds of 600 to 700 RPM), the drill was lifted and the soil was retained inside the bit. To prove this point, the drill was turned horizontally, and the acquired soil was still inside the bit. The basic theory behind the process of retaining unconsolidated mass that can be acquired by the centrifugal forces of the bit is determined by noting that in order to stay inside the interior of the bit, the frictional force must be greater than the weight of the sample. The bit can be designed with an internal sleeve to serve as a container for granular samples. This tube-shaped component can be extracted upon completion of the sampling, and the bottom can be capped by placing the bit onto a corklike component. Then, upon removal of the internal tube, the top section can be sealed. The novel features of this device are: center dot A mechanism of acquiring and retaining granular samples using a coring bit without a closed door. center dot An acquisition bit that has internal structure such as a waffle pattern for compartmentalizing or helical internal flute to propel the sample inside the bit and help in acquiring and retaining granular samples. center dot A bit with an internal spiral into which the various particles wedge. center dot A design that provides a method of testing frictional properties of the granular samples and potentially segregating particles based on size and density. A controlled acceleration or deceleration may be used to drop the least-frictional particles or to eventually shear the unconsolidated material near the bit center.

Bar-Cohen, Yoseph↗
NASA NTRS2018

Auto-Gopher-2 – An Autonomous Wireline Rotary Piezo-Percussive Deep Drilling Mechanism

Drilling deep into the subsurface of planetary bodies in the Solar System for samples acquisition enables critical capabilities for future NASA exploration missions in its quest to understand the origins of the Solar System and potentially the search for life. Such planetary bodies as Mars and Europa are key targets for potential missions that would require reaching great depths. Performing drilling while using minimal mass/volume systems and with low energy consumption are the main requirements that are imposed on such technologies. A wireline deep drill, called Auto-Gopher-2, is currently being developed as a joint effort between JPL and Honeybee Robotics Ltd. The Auto-Gopher II is a wireline rotary piezo-percussive deep drilling mechanism that combines formation breaking by rotating and piezoelectric actuator hammering and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed as an adaptable tool for many drilling and coring applications. The USDC uses an intermediate ball-shape free-mass to transform high frequency vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The lessons learned from the previous studies are being implemented into the development of the Auto-Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics. Subsystems of the wireline drill are being developed in parallel at JPL and Honeybee Robotics, Ltd. Issues related to the bit and its ability to retain the cuttings for caching and removal are currently being addressed. This paper presents the development efforts of the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.

Bar-Cohen, Yoseph↗
NASA NTRS2011

Auto-Gopher: A Wire-Line Rotary-Hammer Ultrasonic Drill

Developing technologies that would enable NASA to sample rock, soil, and ice by coring, drilling or abrading at a significant depth is of great importance for a large number of in-situ exploration missions as well as for earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for records of past and present life on the planet, as well as, the search for water and other resources. A deep corer, called Auto-Gopher, is currently being developed as a joint effort of the JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher is a wire-line rotary-hammer drill that combines rock breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) that has been developed as an adaptable tool for many of drilling and coring applications. The USDC uses an intermediate free-flying mass to transform the high frequency vibrations of the horn tip into a sonic hammering of a drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher. The lessons learned from testing the ice gopher were implemented into the design of the Auto-Gopher by inducing a rotary motion onto the fluted coring bit. A wire-line version of such a system would allow penetration of significant depth without a large increase in mass. A laboratory version of the corer was developed in the NDEAA lab to determine the design and drive parameters of the integrated system. The design configuration lab version of the design and fabrication and preliminary testing results are presented in this paper

life dectection↗
NASA NTRS2017

Auto-Gopher-II – An Autonomous Wireline Rotary-Hammer Ultrasonic Drill

Developing technologies that would enable future NASA exploration missions to penetrate deeper into the subsurface of planetary bodies for sample collection is of great importance. Performing these tasks while using minimal mass/volume systems and with low energy consumption is another set of requirements imposed on such technologies. A deep drill, called Auto-Gopher II, is currently being developed as a joint effort between JPL’s NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher II is a wireline rotary-hammer drill that combines formation breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted auger bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed as an adaptable tool for many drilling and coring applications. The USDC uses an intermediate free-flying mass to transform high frequency vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher and then integrated into a rotary hammer device to develop the Auto-Gopher-I. The lessons learned from these developments are being integrated into the development of the Auto-Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics. Subsystems of the wireline drill are being developed in parallel at JPL and Honeybee Robotics Ltd. This paper presents the development efforts of the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.

Badescu, Mircea↗
NASA NTRS2018

Auto-Gopher-II – A wireline rotary-hammer ultrasonic drill that operates autonomously

An important challenge of exploring the solar system is the ability to penetrate at great depths the subsurface of planetary bodies for sample collection. The requirements of the drilling system are minimal mass, volume and energy consumption. To address this challenge, a deep drill, called the Auto-Gopher II, is currently being developed as a joint effort between JPL’s NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher II is a wireline rotaryhammer drill that combines breaking formations by hammering using a piezoelectric actuator and removing the cuttings by rotating a fluted bit. The hammering is produced by the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that has been developed by the JPL team as an adaptable tool for many drilling and coring applications. The USDC uses an intermediate free-flying mass to convert high frequency vibrations of a piezoelectric transducer horn tip into sonic hammering of the drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher and then integrated into a rotary hammer device to develop the Auto-Gopher-I. The lessons learned from these developments are being integrated into the development of the Auto-Gopher-II, an autonomous deep wireline drill with integrated cuttings and sample management and drive electronics. In this paper the latest development will be reviewed including the piezoelectric actuator, cuttings removal and retention flutes and drive electronics.

Paulsen, Gale L.↗
DOE OSTI2021

Comparison of Rotary and Linear Cutting Methodology in Determining Specific Cutting Energy of Granite

Abstract Single polycrystalline diamond compact (PDC) cutting is a practical technique to understand the rock–tool interactions in drag-bit-type geothermal drilling operations. This paper introduces a rotary cutting method to determine specific cutting energy (SCE) and compares it with the conventional linear cutting method. In this work, granite is selected to represent hard rock formations in geothermal drilling. Cutting tests are conducted on a Computer Numerical Control (CNC) machine with a realistic cutting speed of 12.7 m/min and several chip loads ranging from 0.08 to 0.25 mm. The cutting force is measured using a dynamometer and then converted to specific cutting energy (SCE). The results show that the rotary method produces an inverse relationship between SCE and chip load, whereas the linear method shows the opposite. As a result, the produced SCE by the rotary method tends to be lower than that of the linear method at a higher chip load at and over 0.16 mm. The difference may be attributed to the cutting configuration and associated force components.

Engineering↗
DOE OSTI2023

The Effects of Plasma Pre-Cracking on Drilling of Hard Rocks: A Single Insert Cutting Experiment

Abstract This paper studies the effects of plasma-induced cracks on rock cutting to support the concept of a plasma-integrated drag bit for accelerated geothermal drilling through hard rocks. For this, a single polycrystalline diamond compact (PDC) drilling technique is used in cutting granite to compare thrust and cutting forces between plasma-treated and untreated rock samples. The cracks are produced using underwater plasma at 80 J per pulse. This energy level does not produce visible damage to the rock. The cutting tests are conducted at a cutting speed of 12.7 m/min and four feed rates of 0.127, 0.201, 0.267, and 0.414 mm/s to represent actual drilling scenarios. The results show a general trend of reduction in both thrust and cutting forces for these feed rates, but the magnitude of reduction highly depends on the feed rate. The maximum force reduction of around 50% is found at the 0.267 mm/s feed rate with statistical significance. Cases with a higher force reduction are also found to have rougher surface topography, which indicates more excessive fracturing and, thus, a cracks-accelerated material removal process. This study provides initial evidence of using underwater plasma to increase the downhole drilling rate of hard rocks.

Engineering↗
NASA NTRS2010

Mars Science Laboratory Drill

The Drill for the Mars Science Laboratory mission is a rotary-percussive sample acquisition device with an emphasis on toughness and robustness to handle the harsh environment on Mars. The unique challenges associated with autonomous drilling from a mobile robot are addressed. A highly compressed development schedule dictated a modular design architecture that satisfies the functional and load requirements while allowing independent development and testing of the Drill subassemblies. The Drill consists of four actuated mechanisms: a spindle that rotates the bit, a chuck that releases and engages bits, a novel voice-coil-based percussion mechanism that hammers the bit, and a linear translation mechanism. The Drill has three passive mechanisms: a replaceable bit assembly that acquires and collects sample, a contact sensor / stabilizer mechanism, and, lastly a flex harness service loop. This paper describes the various mechanisms that makeup the Drill and discusses the solutions to their unique design and development challenges.

Okon, Avi B.↗