Download or read book Measurement of in situ stress in salt and rock using NQR techniques Department of Energy Washington D C written by E. Schempp and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Measurement of In situ Stress in Salt and Rock Using NQR Techniques written by Ellery Frank Schempp and published by . This book was released on 1980 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of In situ Stress in Salt and Rock Using NQR Techniques written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

Download or read book Measurement of in situ stress in rock using NQR techniques written by E. Schempp and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1981 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electronic Measurement of Rock Stress written by John C. Cook and published by . This book was released on 1973 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the program was to evaluate feasibility of non-destructive electronic measurement (and logging) of rock stress in situ, using atomic resonances that are pressure-sensitive. Nuclear quadrupole resonance (NQR) appeared clearly applicable, since no magnetic aligning field is needed, there are several common NQR-active nuclear species in major rock-forming minerals, and rf magnetic fields between 0.3 and 3 megahertz (the resonant frequencies) propagate well through many rocks. There are also alternative resonance methods which may be applicable, including NMR, EPR, and EFR. A comprehensive literature search has been completed on NQR in minerals, which shows that aluminum-27 and a few other elements in feldspars are promising for NQR measurement of rock stress. Efforts to detect these resonances in mineral specimens were mostly unsuccessful because of their extreme weakness. The outlook for NQR is now considered marginal. Short studies of other rf spectrographic methods showed that ferromagnetic effects cannot be used, but that electron paramagnetic resonance (EPR) holds some promise as a means of measuring rock stress, since strong EPR signals are readily obtained from most rocks. (Author).

Download or read book In situ Rock Stress written by Ming Lu and published by CRC Press. This book was released on 2006 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding in-situ rock stress is important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying. Traditional methods of determining these stresses have not developed substantially to keep pace with the increasing utilization of rock masses. Contributed by a group of leading experts, this book addresses new developments in numerical modeling and advanced measuring techniques. The papers in In-Situ Rock Stress: Measurement, Interpretation and Application reflect the development in this field, covering measuring techniques, interpretation methods, and application of the in-situ stress in engineering practice.

Download or read book Field Tests of Stress Measurement Techniques in Rock Salt written by John C. Stormont and published by . This book was released on 1984 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Situ Rock Stress Measurement Interpretation and Application written by Abhinav Mishra and published by . This book was released on 2015-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding in-situ rock stress is important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying. Traditional methods of determining these stresses have not developed substantially to keep pace with the increasing utilization of rock masses. Contributed by a group of leading experts, this book addresses new developments in numerical modeling and advanced measuring techniques. In-Situ Rock Stress: Measurement, Interpretation and Application reflect the development in this field, covering measuring techniques, interpretation methods, and application of the in-situ stress in engineering practice. Estimate of the in-situ rock stress state can be realized by direct or indirect methods. Although the indirect method has developed rapidly in recent years, the direct field measurement is still by far dominating. Great improvements have been achieved with the 'traditional' field tests by overcoring and hydraulic fracturing, whilst the recently developed methods become matured. In addition, ideas of new methods and new instruments will make the stress estimate easier, less expensive and more reliable.

Download or read book In Situ Determination of Rock Behavior by Overcore Stress Relief Method Physical Property Measurements and Initial Deformation Method written by and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Situ Measurements of Rock Salt Permeability Changes Due to Nearby Excavation written by and published by . This book was released on 1991 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 x 10−18 m2 at 1.25 r to about the pre-excavation value (10−21 m2) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs.

Download or read book Comparison of Stress measuring Techniques at the DNA UTP Site Rodgers Hollow Kentucky written by R. E. Finley and published by . This book was released on 1994 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Defense Nuclear Agency (DNA) is developing explosives technology through its Underground Technology Program (UTP). Sandia National Laboratories (SNL) has supported the DNA by conducting research to characterize the in situ stress and rock mass deformability at one of the UTP underground sites at Rodgers Hollow, near Louisville, Kentucky on the Fort Knox Military Reservation. The purpose of SNL's testing was to determine the in situ stress using three different measurement techniques and, if possible, to estimate the rock mass modulus near the underground opening. The three stress-measuring techniques are (1) borehole deformation measurements using overcoring, (2) Anelastic Strain Recovery (ASR) complemented by laboratory ultrasonic and mechanical properties testing, and (3) the in situ flatjack technique using cancellation pressure. Rock mass modulus around the underground opening was estimated using the load deformation history of the flatjack and surrounding rock. Borehole deformation measurements using the overcoring technique probably represent the most reliable method for in situ stress determination in boreholes up to 50 ft (15 m) deep in competent rock around an isolated excavation. The technique is used extensively by the tunneling and mining industries. The ASR technique is also a core-based technique and is used in the petroleum and natural gas industries for characterization of in situ stress from deep boreholes. The flatjack technique has also been used in the tunneling and mining industries, and until recently has been limited to measurement of the stress immediately around the excavation. Results from the flatjack technique must be further analyzed to calculate the in situ stress in the far field.

Download or read book Measurement of Rock Properties at Elevated Pressures and Temperatures written by Howard J. Pincus and published by ASTM International. This book was released on 1985 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Examples of Technical Innovations in Rock Property Measurements Prompted by the Waste Isolation Pilot Plant written by and published by . This book was released on 1997 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Waste Isolation Pilot Plant (WIPP) is the U.S. Department of Energy's (DOE) planned repository for transuranic waste generated by defense programs. The WIPP repository 660 meters underground in bedded salt. Bedded salt was chosen for the repository because of salt's small moisture content, extremely low permeability, and its natural ability to flow or creep, effectively encapsulating the waste in the long-term. However, because of these unique characteristics, the ability to measure properties at in situ conditions are beyond the realm of most standard experimental equipment. Thus a suite of new experimental systems and techniques has been developed to measure properties in extremely {open_quotes}tight{close_quotes} (low permeability) rocks. Also, innovations in rock property measurements have been made for standard porous media through the research conducted to characterize the rocks above the repository. A number of the new systems and techniques developed through the WIPP are presented in this paper. Examples include permeameters, two-phase flow characterization equipment, techniques for evaluation of salt healing, and characterization of diffusive processes.

Download or read book Applied Salt rock Mechanics The in situ behavior of salt rocks written by C. A. Baar and published by Elsevier Science & Technology. This book was released on 1977 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: V. 1. The in-situ behavior of salt rocks.

Download or read book In Situ Stress Measurements Park River Project Hartford Connecticut written by Mysore Nataraja and published by . This book was released on 1977 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparative Field Study of Rock Stress Determination Techniques written by Francois Bonnechere and published by . This book was released on 1969 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous different techniques have been developed for the determination of in-situ stresses in rocks. Generally, each system has been designed and calibrated or tested independently of the others. The purpose of this research was to make a comparative study of several different techniques under the same carefully controlled field conditions. A four foot square on a quarry floor was first instrumented and then relieved from any regional stresses by drilling four slots (4 ft. 6 in. long and 9 ft. deep) at right angles around the instrumented region. The piece of rock isolated by this way was then restressed by means of flat jacks inserted in the slots. With this arrangement it was possible to compare the various techniques of rock stress determination in either uniaxial or biaxial stressfields generated by pressurizing the opposite pairs of flat jacks. Results strongly suggest that data obtained from current techniques of stress determination cannot be relied upon within plus or minus 20% to 30% of the mean values, even under carefully controlled conditions. (Author).