My article “Long division solves the mathematics of inverse convolution” in TLE's May issue h... more My article “Long division solves the mathematics of inverse convolution” in TLE's May issue has prompted a number of replies which state essentially that I am performing deterministic deconvolution which is well documented. I have checked the references they cited and am happy to say that such references are difficult to teach by comparison' with my inverse convolution approach.
Summary In the early 1970s, conventional two dimensional (2D) seismic methods were used to unders... more Summary In the early 1970s, conventional two dimensional (2D) seismic methods were used to understand subsurface geological structure. Three dimensional (3D) surveying had not yet arrived as a method for delineating oil fields. Gulf Oil Research Laboratories was working on the problem of how to convince geologists that to delineate complex structure, seismic data should be recorded more closely spaced than was accepted practice. A physical modelling system was constructed utilizing a metre square water tank. Scaled models of geologic structures were suspended in the tank and an ultrasonic source and receiver pair was moved over the models to mimic both conventional 2D and experimental 3D seismic reflection surveys. 3D seismic migration algorithms were developed using the digitally recorded model data. The results clearly demonstrated the pitfalls of using widely spaced 2D seismic lines in the interpretation process – 3D acquisition and processing was required for accurate imaging. Exxon was next to build a physical modelling system. When Gulf was taken over by Chevron, the Gulf modelling system was donated to and installed at the University of Houston, where a new laboratory housed a larger tank. Subsequently, other physical modelling systems were built in China, Japan, Australia, Saudi Arabia and Holland. State-of-the-art recording has changed from single shot to single receiver, to multi-shots into 48 receivers, with further channel expansion soon. From simple impulsive shot recording simulating explosives, the technology has moved to simulation of any form of vibroseis sweep or frequency required. From simple plastic models, the technology has moved into the realm of injecting fluids into real sand reservoirs in pressure vessels. This paper will discuss the changing face of seismic physical modelling.
Research is currently being undertaken in Australia to develop new drilling technologies for deep... more Research is currently being undertaken in Australia to develop new drilling technologies for deep mineral exploration. The Deep Exploration Technologies Cooperative Research Centre (DET CRC) has carried out a comprehensive review of the available drilling technologies in the market. Following the study, coiled tube drilling technology has been suggested as a faster and cheaper method than conventional pipe drilling. This is primarily due to its smaller footprint relative to the standard rotary method, ease of unit mobility, less operating personnel, faster rate of penetration, and faster rig up and rig down times. The steel coiled tubing technology has traditionally been used in the petroleum industry. While there have been several attempts to evaluate the performance of coiled tubes in the oil and gas industry, limited or no attempts have been made to assess its performance in deep hard rock mineral exploration drilling. Therefore, DET CRC is in the process of re-designing the coiled tube rig approach to enable fast and efficient drilling of deep micro-holes in hard rocks. Cyclic bending of the coiled tubing past the yield strength point of the material leads to progressive weakening of the tube, which accordingly leads to rapid reduction of the tube service life [1]. Hence fatigue is an important parameter that needs to be considered in material selection for coiled tube and rig design. A bending machine was designed and manufactured to evaluate the fatigue bending strength of conventional HSLA steel tubes. The machine is capable of measuring and recording the bending/flattening resistant forces of the tubes along with the number of bend/flatten events. It can also measure the strain applied on the tube if needed. In this study, several HSLA steel grades and thicknesses of coiled tubes were tested for fatigue bending strength. Fatigued and non-fatigued tubes had their mechanical property alteration tested using tensile test methods. This paper presents the fatigue bending machine. The machine is designed to test most material types of coiled tubes. The paper also reports results of the cyclic bending experiments that were performed on selected grades and sizes of conventional HSLA steel coiled tubes. The paper complements and enhances the understanding of the performance of conventional coiled tube material under fatigue bending conditions
It is common practice to use changes in fluid transmission velocity to determine whether a fluid ... more It is common practice to use changes in fluid transmission velocity to determine whether a fluid is in gas or liquid phase during pore pressure changes, but transmission amplitude also changes when fluid phase changes during pore pressure reduction. We used two sizes of glass beads in a low-pressure cell to simulate porous rock and conducted experiments with pore spaces filled with distilled water, and with distilled water in which [Formula: see text] of [Formula: see text] was dissolved. Ultrasonic transmission tests above and below bubble point showed that transmission frequencies and amplitudes were higher for distilled water and the smaller beads. There was a greater reduction in frequencies and amplitudes when gas was liberated by scattering from the small gas bubbles associated with the small beads. The water-[Formula: see text] mixture produced higher transmission amplitudes than distilled wateralone, which is consistent with increasing fluid density in the pores. Although He...
The audio range of high fidelity equipment is extremely wide, from 2 Hz to 15 kHz approximately. ... more The audio range of high fidelity equipment is extremely wide, from 2 Hz to 15 kHz approximately. A single audio speaker cannot maintain efficient operation across the spectrum, so in order to compensate for the losses in efficiency, hi-fi enthusiasts use three speakers with over-lapping spectral operation. Thus, a broad-band signal is produced using a 'woofer' for low frequencies, a 'squarker' for medium range frequencies, and a 'tweeter' for the higher frequencies. The useful seismic spectrum is limited to a range of 2 Hz to 400 Hz. The range of 2 Hz to 120 Hz is of particular interest to the oil explorer with present technology. In order to image reservoirs successfully, methods of signal enhancement and noise reduction have been designed to improve low signal-to-noise ratios. In order to reduce the harmful signal-masking effects of surface waves, geophone strings spread over the surface waves' length are used in an attempt to attenuate coherent ground ...
My article “Long division solves the mathematics of inverse convolution” in TLE's May issue h... more My article “Long division solves the mathematics of inverse convolution” in TLE's May issue has prompted a number of replies which state essentially that I am performing deterministic deconvolution which is well documented. I have checked the references they cited and am happy to say that such references are difficult to teach by comparison' with my inverse convolution approach.
Summary In the early 1970s, conventional two dimensional (2D) seismic methods were used to unders... more Summary In the early 1970s, conventional two dimensional (2D) seismic methods were used to understand subsurface geological structure. Three dimensional (3D) surveying had not yet arrived as a method for delineating oil fields. Gulf Oil Research Laboratories was working on the problem of how to convince geologists that to delineate complex structure, seismic data should be recorded more closely spaced than was accepted practice. A physical modelling system was constructed utilizing a metre square water tank. Scaled models of geologic structures were suspended in the tank and an ultrasonic source and receiver pair was moved over the models to mimic both conventional 2D and experimental 3D seismic reflection surveys. 3D seismic migration algorithms were developed using the digitally recorded model data. The results clearly demonstrated the pitfalls of using widely spaced 2D seismic lines in the interpretation process – 3D acquisition and processing was required for accurate imaging. Exxon was next to build a physical modelling system. When Gulf was taken over by Chevron, the Gulf modelling system was donated to and installed at the University of Houston, where a new laboratory housed a larger tank. Subsequently, other physical modelling systems were built in China, Japan, Australia, Saudi Arabia and Holland. State-of-the-art recording has changed from single shot to single receiver, to multi-shots into 48 receivers, with further channel expansion soon. From simple impulsive shot recording simulating explosives, the technology has moved to simulation of any form of vibroseis sweep or frequency required. From simple plastic models, the technology has moved into the realm of injecting fluids into real sand reservoirs in pressure vessels. This paper will discuss the changing face of seismic physical modelling.
Research is currently being undertaken in Australia to develop new drilling technologies for deep... more Research is currently being undertaken in Australia to develop new drilling technologies for deep mineral exploration. The Deep Exploration Technologies Cooperative Research Centre (DET CRC) has carried out a comprehensive review of the available drilling technologies in the market. Following the study, coiled tube drilling technology has been suggested as a faster and cheaper method than conventional pipe drilling. This is primarily due to its smaller footprint relative to the standard rotary method, ease of unit mobility, less operating personnel, faster rate of penetration, and faster rig up and rig down times. The steel coiled tubing technology has traditionally been used in the petroleum industry. While there have been several attempts to evaluate the performance of coiled tubes in the oil and gas industry, limited or no attempts have been made to assess its performance in deep hard rock mineral exploration drilling. Therefore, DET CRC is in the process of re-designing the coiled tube rig approach to enable fast and efficient drilling of deep micro-holes in hard rocks. Cyclic bending of the coiled tubing past the yield strength point of the material leads to progressive weakening of the tube, which accordingly leads to rapid reduction of the tube service life [1]. Hence fatigue is an important parameter that needs to be considered in material selection for coiled tube and rig design. A bending machine was designed and manufactured to evaluate the fatigue bending strength of conventional HSLA steel tubes. The machine is capable of measuring and recording the bending/flattening resistant forces of the tubes along with the number of bend/flatten events. It can also measure the strain applied on the tube if needed. In this study, several HSLA steel grades and thicknesses of coiled tubes were tested for fatigue bending strength. Fatigued and non-fatigued tubes had their mechanical property alteration tested using tensile test methods. This paper presents the fatigue bending machine. The machine is designed to test most material types of coiled tubes. The paper also reports results of the cyclic bending experiments that were performed on selected grades and sizes of conventional HSLA steel coiled tubes. The paper complements and enhances the understanding of the performance of conventional coiled tube material under fatigue bending conditions
It is common practice to use changes in fluid transmission velocity to determine whether a fluid ... more It is common practice to use changes in fluid transmission velocity to determine whether a fluid is in gas or liquid phase during pore pressure changes, but transmission amplitude also changes when fluid phase changes during pore pressure reduction. We used two sizes of glass beads in a low-pressure cell to simulate porous rock and conducted experiments with pore spaces filled with distilled water, and with distilled water in which [Formula: see text] of [Formula: see text] was dissolved. Ultrasonic transmission tests above and below bubble point showed that transmission frequencies and amplitudes were higher for distilled water and the smaller beads. There was a greater reduction in frequencies and amplitudes when gas was liberated by scattering from the small gas bubbles associated with the small beads. The water-[Formula: see text] mixture produced higher transmission amplitudes than distilled wateralone, which is consistent with increasing fluid density in the pores. Although He...
The audio range of high fidelity equipment is extremely wide, from 2 Hz to 15 kHz approximately. ... more The audio range of high fidelity equipment is extremely wide, from 2 Hz to 15 kHz approximately. A single audio speaker cannot maintain efficient operation across the spectrum, so in order to compensate for the losses in efficiency, hi-fi enthusiasts use three speakers with over-lapping spectral operation. Thus, a broad-band signal is produced using a 'woofer' for low frequencies, a 'squarker' for medium range frequencies, and a 'tweeter' for the higher frequencies. The useful seismic spectrum is limited to a range of 2 Hz to 400 Hz. The range of 2 Hz to 120 Hz is of particular interest to the oil explorer with present technology. In order to image reservoirs successfully, methods of signal enhancement and noise reduction have been designed to improve low signal-to-noise ratios. In order to reduce the harmful signal-masking effects of surface waves, geophone strings spread over the surface waves' length are used in an attempt to attenuate coherent ground ...
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