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Accuracy of offshore subsidence measured with seabed pressure gauges
237A covariance structure of the measured data. Effects of geologic uncertainty are evaluated by computing a performance model for a number of geologic simulations. The technique is illustrated to assess unsaturated groundwater travel times at Yucca Mountain using preliminary geologic models of unsaturated permeability.
Monitoring rock and soil mass performance See also: 924086, 924507 924249 Data acquisition system for geotechnical instrumentation and design De Souza, E M CIM Bull II85, N956, Jan 1992, P43-47 Instrumentation is an essential tool to assure safety and assist in design verification and production optimisation in underground mines. Automated data acquisition systems allow realtime trends in rock mass behaviour to be assessed and potential dangers indicated. A computer based system is described, with both data acquisition hardware and software discussed. Field applications to monitoring sill pillar extraction, stope stability, and crown pillar stability, including layout of stressmeters and extensometers, are illustrated. 92425O New development in test drilling for detection of hazards in rock burst prevention (In German) Bruckmann, S; Asshoff, U Giuckauf V127. N23/24, Dec 1991. P1047-1051 A drilling monitoring system is described which is under development to detect potential rockburst conditions by inferring state of stress in the rock mass from measurement of force on the drill bit. Similar efforts using torque monitoring were unsuccessful. Statistical analysis of signals from 1928m drilled in 247 boreholes has allowed determination of criteria for recognition of increased rock stress. 924251 Examination of initial rotation error in portable borehole deflectometers. Technical note Kumbhojkar, A J Geotech Engng Div ASCE VII7, NI2. Dec 1991, P19491955 The PBD is a transverse deformation gauge similar to inclinometers used for measuring ground movement. It typically has resolution an order of magnitude higher than the inclinometer, but is vulnerable to a systematic error called the initial rotation. The instrument, source of error, and a procedure for error elimination are described. An illustrative example of use of the PBD to study response of buried pipes to excavation of an adjacent trench is presented. 924252 Advances in MWD technology improve real time data Burgess, T; Voisin, B Oil Gas J V90, N7, Feb 1992, P51-61 Measurement While Drilling provides reliable and cost-effective surveys with real time data before invasion and reduced likelihood of missing a pay zone. One of the latest generation of MWD systems, incorporated with a steerable bottom hole assembly, is illustrated. It can include modules for resistivity, gamma ray, neutron, and seismic logging, telemetry, and monitoring of bit weight and torque and power requirements. Field logs are illustrated and interpretations discussed.
924253 Accuracy of offshore subsidence measured with seabed pressure gauges Mes, M J SPE Form Eval V6, N4, Dec 1991, P463-469 The use of pressure gauges to monitor offshore platform subsidence was pioneered by Phillips Petroleum in the Norwegian North Sea. The gauges are installed on selected platforms near the mudline and repeated measurements for absolute pressure are made. Relative subsidence between platforms is calculated on the basis of 6 or 10 day average values for one platform as compared to another. The principle and instrumentation are illustrated. Prototype results indicate progression of subsidence can be measured with a relative uncertainty of +/-9ram.
924254 On line fragment size analyser using image processing techniques Cheung, C C; Ord, A Proe 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P233-238. Publ Parkviile: AuslMM, 1990 A real time method for assessing rock fragment size distribution is described. It is based on an active image processing technique, stereosis,where a light stripe is projected on to the surface of the rock fragments on the conveyor belt. A TV camera is used to capture the shape of the distorted light stripe and the video image processed to determine the 3D profile of the surface. Sizes of the fragments are calculated from this profile.
924255 Blast monitoring: from detonation to impact Hickey, S M Proc 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P259-264. Publ Parkville: AuslMM, 1990 Blasting experiments are generally carried out in the field, often in a production environment, they are dynamic and seldom repeatable, and have particular safety requirements. Instrumentation for data acquisition at all stages is described: transducers, cabling and connections, signal recording, shock wave measurement, and recording of ground movement and overpressure.
924256 Radio noise monitoring during rock fracture at blast sites O'Keefe, S G; Thiel, D V Proc 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P279-281. Publ Parkville : AuslMM, 1990 Radio noise has been recorded during earthquakes and rock fracture. The source is probably rock fracture. Electric field recordings (EM radiation) have been made during blasting at two phyllite rock quarries near Brisbane. Large signals were obtained for most blasts. A variety of antenna layouts was used, with best results recorded for antenna located directly in front of the blast face. Preliminary analysis indicates 3 types of signals, related to hole detonation, rock fall, and post blast relaxation. The EM recording technique may have potential for development into a blast monitoring system.
© 1992 Pergamon Press Ltd. Reproduction not permitted
Monitoring rock and soil mass performance See also: 924086, 924507 924249 Data acquisition system for geotechnical instrumentation and design De Souza, E M CIM Bull II85, N956, Jan 1992, P43-47 Instrumentation is an essential tool to assure safety and assist in design verification and production optimisation in underground mines. Automated data acquisition systems allow realtime trends in rock mass behaviour to be assessed and potential dangers indicated. A computer based system is described, with both data acquisition hardware and software discussed. Field applications to monitoring sill pillar extraction, stope stability, and crown pillar stability, including layout of stressmeters and extensometers, are illustrated. 92425O New development in test drilling for detection of hazards in rock burst prevention (In German) Bruckmann, S; Asshoff, U Giuckauf V127. N23/24, Dec 1991. P1047-1051 A drilling monitoring system is described which is under development to detect potential rockburst conditions by inferring state of stress in the rock mass from measurement of force on the drill bit. Similar efforts using torque monitoring were unsuccessful. Statistical analysis of signals from 1928m drilled in 247 boreholes has allowed determination of criteria for recognition of increased rock stress. 924251 Examination of initial rotation error in portable borehole deflectometers. Technical note Kumbhojkar, A J Geotech Engng Div ASCE VII7, NI2. Dec 1991, P19491955 The PBD is a transverse deformation gauge similar to inclinometers used for measuring ground movement. It typically has resolution an order of magnitude higher than the inclinometer, but is vulnerable to a systematic error called the initial rotation. The instrument, source of error, and a procedure for error elimination are described. An illustrative example of use of the PBD to study response of buried pipes to excavation of an adjacent trench is presented. 924252 Advances in MWD technology improve real time data Burgess, T; Voisin, B Oil Gas J V90, N7, Feb 1992, P51-61 Measurement While Drilling provides reliable and cost-effective surveys with real time data before invasion and reduced likelihood of missing a pay zone. One of the latest generation of MWD systems, incorporated with a steerable bottom hole assembly, is illustrated. It can include modules for resistivity, gamma ray, neutron, and seismic logging, telemetry, and monitoring of bit weight and torque and power requirements. Field logs are illustrated and interpretations discussed.
924253 Accuracy of offshore subsidence measured with seabed pressure gauges Mes, M J SPE Form Eval V6, N4, Dec 1991, P463-469 The use of pressure gauges to monitor offshore platform subsidence was pioneered by Phillips Petroleum in the Norwegian North Sea. The gauges are installed on selected platforms near the mudline and repeated measurements for absolute pressure are made. Relative subsidence between platforms is calculated on the basis of 6 or 10 day average values for one platform as compared to another. The principle and instrumentation are illustrated. Prototype results indicate progression of subsidence can be measured with a relative uncertainty of +/-9ram.
924254 On line fragment size analyser using image processing techniques Cheung, C C; Ord, A Proe 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P233-238. Publ Parkviile: AuslMM, 1990 A real time method for assessing rock fragment size distribution is described. It is based on an active image processing technique, stereosis,where a light stripe is projected on to the surface of the rock fragments on the conveyor belt. A TV camera is used to capture the shape of the distorted light stripe and the video image processed to determine the 3D profile of the surface. Sizes of the fragments are calculated from this profile.
924255 Blast monitoring: from detonation to impact Hickey, S M Proc 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P259-264. Publ Parkville: AuslMM, 1990 Blasting experiments are generally carried out in the field, often in a production environment, they are dynamic and seldom repeatable, and have particular safety requirements. Instrumentation for data acquisition at all stages is described: transducers, cabling and connections, signal recording, shock wave measurement, and recording of ground movement and overpressure.
924256 Radio noise monitoring during rock fracture at blast sites O'Keefe, S G; Thiel, D V Proc 3rd International Symposium on Rock Fragmentation by Blasting, Brisbane, 26-31 Aug 1990 P279-281. Publ Parkville : AuslMM, 1990 Radio noise has been recorded during earthquakes and rock fracture. The source is probably rock fracture. Electric field recordings (EM radiation) have been made during blasting at two phyllite rock quarries near Brisbane. Large signals were obtained for most blasts. A variety of antenna layouts was used, with best results recorded for antenna located directly in front of the blast face. Preliminary analysis indicates 3 types of signals, related to hole detonation, rock fall, and post blast relaxation. The EM recording technique may have potential for development into a blast monitoring system.
© 1992 Pergamon Press Ltd. Reproduction not permitted