Abstract: A fluid density determination apparatus and method comprising an X-ray generator emitting a high energy radiation signal and a low energy radiation signal; a sample cell housing a sample of interest and at least one of the high energy and low energy radiation signals being directed through the sample cell; and a radiation detector measuring the output radiation from the sample cell. Data gathered at the radiation detector using the high and low energy signals are used to calculate the density of the fluid sample of interest.

Abstract: A wireline-conveyed side-wall core coring tool for acquiring side-wall core from a geological formation for performing in-situ side-wall core analysis. The coring tool has a core analysis unit operable to measure geophysical properties of an acquired side-wall core. The measured geophysical properties may be used to determine the success of the acquisition of side-wall cores by the coring tool. The core analysis unit is operable of performing an in-situ interpretation of measured geophysical property of the side-wall core and transmitting in near real-time the measurements or the interpretation results to surface data acquisition and processing apparatus.

Abstract: The invention relates to methods and apparatus for determining downhole mud flow rates and other downhole parameters. A method for determining a downhole parameter includes operating a pulsed neutron generator (6), pulsing the pulsed neutron generator (6) off, detecting a substantially unactivated drilling fluid slug at a known distance (d) from the pulsed neutron generator (6), and determining a time-of-flight (t) for the unactivated drilling fluid slug to travel from the pulsed neutron generator (6) to a detection point.

Abstract: A tool for formation logging includes a support configured for movement in a borehole; a neutron source disposed on the support; a neutron monitor disposed on the support and configured to monitor an output of the neutron source; a gamma-ray detector disposed on the support and spaced apart from the neutron source; and a shielding material disposed between the gamma-ray detector and the neutron source.

Abstract: The invention relates to methods and apparatus for determining a downhole parameter in an underbalanced drilling environment which include: selectively activating a first fluid flowing from the formation through a wellbore while under balanced drilled; detecting the activated first fluid; and determining a depth at which said fluid enters the wellbore.

Abstract: A system and method are disclosed for detecting radiation phenomena in an area surrounding a wellbore traversing an earth formation. A logging instrument is equipped with combined radiation detectors to provide multiple measurements at the same axial position along the instrument axis, without the use of rotating parts within the instrument. Shielded or segmented detectors provide azimuthally focused detector sensitivity. A controllable radiation source is optionally disposed on the instrument for subsurface irradiation. Also disclosed is the use of radioactive materials in unison with the logging instrument to determine subsurface flow and reservoir characteristics.

Abstract: A system and method are disclosed for detecting radiation phenomena in an area surrounding a wellbore traversing an earth formation. A logging instrument is equipped with combined radiation detectors to provide multiple measurements at the same axial position along the instrument axis, without the use of rotating parts within the instrument. Shielded or segmented detectors provide azimuthally focused detector sensitivity. A controllable radiation source is optionally disposed on the instrument for subsurface irradiation. Also disclosed is the use of radioactive materials in unison with the logging instrument to determine subsurface flow and reservoir characteristics.

Abstract: A method and apparatus for characterizing a multiphase mixture by irradiating the mixture with X-rays, collecting the photons that emanate from the mixture in response to the irradiation, generating a signal responsive to the aggregate energy of the collected photons, and analyzing the signal to characterize the mixture. Preferably, the mixture is irradiated by repetitively pulsing an X-ray tube and the photons are collected using a multi-layer detector. The method and apparatus may be used to determine the flow rate, flow velocities, and/or composition of the multiphase mixture. In other embodiments, a plurality of X-ray sources and/or detectors may be used.

Abstract: Video systems and methods for determining the length of objects to be inserted in a wellbore, and for summing the lengths to obtain an accurate determination of the depth at which a bottomhole assembly is located at any given time. The video systems and methods of the present invention are also used in conjunction with hookload and traveling block location information to determine bottomhole assembly depth while drilling, or tripping-in or tripping out of a well. Also disclosed is a method of accurately determining the transition a drillstring undergoes and its associated movement when passing from in-slips to out-of-slips.

Abstract: The porosities of subsurface earth formations surrounding a borehole are investigated using a logging tool run in the wellbore by repeatedly irradiating the formations with discrete bursts of high energy neutrons, measuring the populations of epithermal neutrons at near and far locations from the neutron source, and also measuring the rate of decay of the epithermal neutron population at a third location following each neutron burst and deriving therefrom a measurement of the epithermal neutron slowing down time. Formation porosity values derived from the near-and-far location population measurements are corrected for detector standoff effects by use, in accordance with a predetermined empirical relationship, of the epithermal slow down time measurement.

Abstract: A communications system for providing communication between a downhole well logging apparatus and external equipment in which a portion of the external equipment is placed in an aperature in a side wall of the well logging and electromagnetic signals are exchanged.