The Subsurface Telemetry Problem-A Practical Solution

Arps, J.J.; Arps, Jan L.

doi:10.2118/710-pa

Cited by 34 publications

(16 citation statements)

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“…The forces acting on the pleural fluid and lung interface are assumed to be in equilibrium, with the lung displacing pleural fluid, and capillary forces retaining a film of pleural fluid (40). The force generated by the weight of the elevated pleural fluid acting against the lung is balanced by the negative pull of the surface tension forces at all levels and the buoyancy pressure generated by the lung floating in the pleural fluid ( Figure 1).…”

Section: Equilibriummentioning

confidence: 99%

“…The volume of pleural fluid remaining at a given height in the pleural space is a function of the balance of capillary forces pulling the pleural fluid up and the force of gravity acting together with the density contrast between the lung and pleural fluid, operating to remove the pleural fluid down (40). The capillary-bound pleural fluid comprises a continuous column of pleural fluid, which will have a pressure gradient controlled by the pleural fluid density.…”

Section: Why the Hydrostatic Vertical Pleural Pressure Gradient Is Himentioning

confidence: 99%

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Pleural pressure theory revisited: a role for capillary equilibrium

Casha¹,

Caruana‐Gauci²,

Manche³

et al. 2017

J. Thorac. Dis.

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Background: Theories elucidating pleural pressures should explain all observations including the equal and opposite recoil of the chest wall and lungs, the less than expected pleural hydrostatic gradient and its variation at lobar margins, why pleural pressures are negative and how pleural fluid circulation functions.Methods: A theoretical model describing equilibrium between buoyancy, hydrostatic forces, and capillary forces is proposed. The capillary equilibrium model described depends on control of pleural fluid volume and protein content, powered by an active pleural pump. Results:The interaction between buoyancy forces, hydrostatic pressure and capillary pressure was calculated, and values for pleural thickness and pressure were determined using values for surface tension, contact angle, pleural fluid and lung densities found in the literature. Modelling can explain the issue of the differing hydrostatic vertical pleural pressure gradient at the lobar margins for buoyancy forces between the pleural fluid and the lung floating in the pleural fluid according to Archimedes' hydrostatic paradox. The capillary equilibrium model satisfies all salient requirements for a pleural pressure model, with negative pressures maximal at the apex, equal and opposite forces in the lung and chest wall, and circulatory pump action.Conclusions: This model predicts that pleural effusions cannot occur in emphysema unless concomitant heart failure increases lung density. This model also explains how the non-confluence of the lung with the chest wall (e.g., lobar margins) makes the pleural pressure more negative, and why pleural pressures would be higher after an upper lobectomy compared to a lower lobectomy. Pathological changes in pleural fluid composition and lung density alter the equilibrium between capillarity and buoyancy hydrostatic pressure to promote pleural effusion formation.

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Section: Equilibriummentioning

confidence: 99%

Section: Why the Hydrostatic Vertical Pleural Pressure Gradient Is Himentioning

confidence: 99%

Pleural pressure theory revisited: a role for capillary equilibrium

Casha¹,

Caruana‐Gauci²,

Manche³

et al. 2017

J. Thorac. Dis.

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“…Mud pulse technology was initially implemented in the mid-1960s by Arps J.J et al who presented details of the first implementation as well as a commendable review of the state of the art in wellbore logging [16]. The first mechanical mud pulse system was marketed in 1964 by Teledrift for transmitting directional information [17].…”

Section: Introductionmentioning

confidence: 99%

The Simulation of Fluid Dynamics inside the Continuous Wave Mud Pulser Generator with Four-hole Rotary Valve

Di¹,

Zhang²,

Jin³

et al. 2017

Proceedings of the 3rd Annual International Conference on Mechanics and Mechanical Engineering (MME 2016)

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Abstract. The continuous wave pulse generator with rotary valve is an advanced and key equipment in high-rate measurement while drilling (MWD) and logging while drilling (LWD) telemetry systems. It generates an encoded mud pressure wave signal to transmit real-time information from down-hole to surface. For the sake of the transmission distance of the signal and the intensity of the signal, an optimized condition for the generator should be clarified, i.e. maximizing mud-pulse pressure while simultaneously minimizing the power consumed by the rotor. In this study, the CFD method was utilized to analyse the velocity and pressure field inside a four-hole rotary valve under different working conditions, and the effect of four key parameters, the mud flow, the rotational speed of the rotor, the axial gap between stator and rotor and the radial gap between rotor and housing, was studied on the performance of the generator. The results showed that the amplitude of the mud pressure and the power consumed by the rotor increased if the flow rate increased and decreased with the increase of the magnitude of the axial gap and the radial gap. Once the axial gap or the radial gap was reduced, a negative pressure zone raised which is adjacent to the region behind the rotor, thus hindered the flow. When the axial gap was reduced by 50%, the amplitude of the mud pressure and the power consumed by the rotor were raised by78.8% and 73.2% respectively. Similarly, as the radial gap was reduced by 50%, the amplitude of the mud pressure was increased by 67.1% and the power consumed by the rotor was increased by 107.7%.The rotational speed of the rotor remarkably affected the power consumed by the rotor and the period of the generated signal as well. However, it indicated no significant influence on the amplitude of the mud pressure. The findings are helpful in understanding the mechanism of continuous wave signal generators with rotary valve and the effects of key factors on its dynamic performance.

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“…, a carbon steel pipe and a stainless steel pipe) and a National Instrument PXI acoustical measurement system that includes an arbitrary waveform generator and a digitizer. We note that data communication schemes using elastic waves have been reported for, for example, flood detection in oil rigs (see, e.g., [23,24]), drill string telemetry [25] in the measurement while drilling (MWD) and logging while drilling (LWD) services in the oil and gas industry [26,27] or Lamb wave communication (see e.g., [28]); systematic studies of high data rate communication schemes using elastic waves are lacking. We note that a pulse position modulation scheme using guided acoustic waves for flood detection was proposed in [23,24].…”

Section: Introductionmentioning

confidence: 99%

Data Communications Using Guided Elastic Waves by Time Reversal Pulse Position Modulation: Experimental Study

Jin

Ying

Zhao

2013

Sensors

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In this paper, we present and demonstrate a low complexity elastic wave signaling and reception method to achieve high data rate communication on dispersive solid elastic media, such as metal pipes, using piezoelectric transducers of PZT (lead zirconate titanate). Data communication is realized using pulse position modulation (PPM) as the signaling method and the elastic medium as the communication channel. The communication system first transmits a small number of training pulses to probe the dispersive medium. The time-reversed probe signals are then utilized as the information carrying waveforms. Rapid timing acquisition of transmitted waveforms for demodulation over elastic medium is made possible by exploring the reciprocity property of guided elastic waves. The experimental tests were conducted using a National Instrument PXI system for waveform excitation and data acquisition. Data telemetry bit rates of 10 kbps, 20 kbps, 50 kbps and 100 kbps with the average bit error rates of 0, 5.75 x 10-4, 1.09 x 10-2 and 5.01 x 10-2, respectively, out of a total of 40, 000 transmitted bits were obtained when transmitting at the center frequency of 250 kHz and a 500 kHz bandwidth on steel pipe specimens. To emphasize the influence of time reversal, no complex processing techniques, such as adaptive channel equalization or error correction coding, were employed.

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The Subsurface Telemetry Problem-A Practical Solution

Cited by 34 publications

References 0 publications

Pleural pressure theory revisited: a role for capillary equilibrium

Pleural pressure theory revisited: a role for capillary equilibrium

The Simulation of Fluid Dynamics inside the Continuous Wave Mud Pulser Generator with Four-hole Rotary Valve

Data Communications Using Guided Elastic Waves by Time Reversal Pulse Position Modulation: Experimental Study

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