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The use of a multichannel analyzer for the analysis of waveforms is described. A gated receiver coupled to the analyzer forms a ``digital boxcar integrator'' when the analyzer is operated as a pulse height analyzer. This arrangement has been used to study the backscattering of acoustic energy from water waves generated in a wind-tunnel. The method is also applicable to the detailed study of the shape and stability of a repetitive pulse.

Observation of cuttings and cavings serves as an important early indicator for hole cleaning and wellbore instability problems. Automation of this critical monitoring process is, however, still in its infancy. This paper highlights the development and initial field testing of a new automated cuttings and cavings monitoring sensor system. Initial challenges identified in an earlier field test, and their solutions that have been incorporated into this new working field prototype, are presented. The imaging sensors selected for the prototype, including a 3D laser profile scanner and a machine vision camera, were used in an initial field trial to assess the feasibility of building a prototype that can operate in a harsh field environment. Based on that initial field trial, the prototype was built, and preliminary outdoor tests were conducted offsite to validate its performance. Following that, a second field trial at an active drilling site in West Texas was conducted to assess the implementation and performance of the prototype in the field. Practical solutions to key challenges identified in the first field trial were successfully implemented in the new prototype, and its field performance was validated in the second field trial where the prototype was integrated into the solids control system of an active drilling rig, successfully collecting data for during drilling operations. The system accurately measured the volumetric return of cuttings, and the tests demonstrate the ability to determine the cuttings size distribution and detect anomalous-sized cavings. The results can be used directly for improved hole cleaning management and stuck pipe avoidance in field operations. This paper introduces the first working prototype of a 3D-imaging cuttings monitoring system that could be taken into production for quantifying the volumetric return of cuttings on surface and providing information about the size and shape of cuttings and cavings. The development of this cuttings sensor is a major milestone in the field of drilling automation, bringing the industry closer to achieving a fully automated hole cleaning and stuck pipe prevention system.

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This paper reports an attempt to measure the asymmetry of wind-generated water waves by using acoustical methods. A 40-foot wind-tunnel water flume provided a controlled water surface that was insonified from above at 162 kHz with pulses 30 µsec in duration (5 cycles). The scattered-pressure amplitude pulses were analyzed statistically as a function of the shear stress produced at the water surface by the wind. Depending on the angle between the transducer and the water surface, the statistical amplitude ratio and energy ratio (upwind/ downwind) of the backscattered pulse were found to be a single-valued function of the water-surface shear over a significant range of wind speeds and scattering angles.