Abstract: A method and apparatus for laboratory simulation of the dynamic formation of sand arches in production of oil and/or gas from unconsolidated or poorly consolidated wells is disclosed. An ultrasonic transducer is disposed opposite a perforation in a member simulating the casing of a well and the simulated well is operated at conditions approximating those of interest in the field. The acoustic transducer is moved incrementally across the perforation and measurements of the distance between the transducer and the formation are measured. These can then be used to generate a profile of the surface of the formation behind the perforation. Preferably, an ultrasonic transducer which emits a focussed beam of acoustic energy is employed.

Abstract: A sand screen is positioned in a well adjacent an oil or gas reservoir to be produced. At least one conduit is in juxtaposition with the sand screen and has passageways at selected intervals to establish fluid communication between the conduit and the annulus of the well surrounding the sand screen. A gravel packing slurry is injected down the well to form a gravel pack in the annulus. Actuatable devices associated with the conduit passageways control fluid flow between the conduit and annulus so that if the gravel portion of the slurry forms a bridge in the annulus, thereby blocking slurry flow through the annulus, the slurry will be diverted from the annulus into the conduit through one or more of the passageways in the conduit above the bridge, downward through the conduit and out through one or more passageways in the conduit into the annulus below the bridge to continue the forming of the gravel pack in the annulus.