Survey of boreholes or wells

EFIXED CONSTRUCTIONS E21Mining E21BEARTH DRILLING

E21B47/00Survey of boreholes or wells

E21B47/0001for underwater installations E21B47/0002Survey of boreholes or wells by visual inspection E21B47/0003Determining well or borehole volumes E21B47/0005control of cementation quality or level E21B47/0006Measuring stresses in a well bore pipe string or casing E21B47/0007Survey of down-hole pump systems E21B47/0008Survey of walking-beam pump systems E21B47/01Devices for supporting measuring instruments on a drill pipe, rod or wireline; Protecting measuring instruments in boreholes against heat, shock, pressure or the like E21B47/011Protecting measuring instruments E21B47/02Determining slope or direction E21B47/022of the borehole E21B47/02208using seismic or acoustic means E21B47/02216using at least one source of electromagnetic energy and at least one detector therefor E21B47/02224at least one of the sources or one of the detectors being located above ground E21B47/02232using a pendulum E21B47/024of devices in the borehole E21B47/026of penetrated ground layers E21B47/04Measuring depth or liquid level E21B47/042Measuring or locating liquid level E21B47/044using radioactive markers E21B47/06Measuring temperature or pressure E21B47/065Measuring temperature E21B47/08Measuring the diameter E21B47/082using radiant means E21B47/09Locating or determining the position of objects in boreholes or wells E21B47/0905by detecting magnetic anomalies E21B47/091by detecting an acoustic anomaly E21B47/0915using impression packers E21B47/10Locating fluid leaks, intrusions or movements E21B47/1005using thermal measurements E21B47/101using acoustic energy E21B47/1015using tracers: using radioactivity E21B47/102using electrical indications: using light radiations E21B47/1025Detecting leaks E21B47/12Means for transmitting measuring-signals or control signals from the well to the surface or from the surface to the well E21B47/121using earth as an electrical conductor E21B47/122by electromagnetic energy E21B47/123using light waves E21B47/124Storing data down-hole E21B47/14using acoustic waves E21B47/16through the drill string or casing E21B47/18through the well fluid E21B47/182by continuous mud waves with modulation of the waves E21B47/185by negative mud pulses using a pressure relieve valve between drill pipe and annulus E21B47/187by positive mud pulses using a flow restricting valve within the drill pipe