摘要:
Fluid containing free gas and in a pipeline or container at a refinery or at any of various petroleum producing operations is bombarded with neutrons and high energy gamma rays resulting from capture of thermal neutrons are detected. The spectra of the detected gamma rays are then analyzed to determine the concentration of the elements chlorine and hydrogen. The counting rate for thermal neutron gamma rays for hydrogen permits a measure of the hydrogen index (HI) of the fluid to be obtained. The hydrogen index and the relative concentrations of chlorine and hydrogen are used to obtain an indication of the presence and concentration of chlorine or salt water in the fluid.
摘要:
Fluid in a pipeline or container at a refinery or at any of various petroleum producing operations is bombarded with neutrons, and high energy gamma rays resulting from capture of thermal neutrons are detected. The spectra of the detected gamma rays are then analyzed to determine the concentration of the element chlorine, which gives an indication of the presence and concentration of salt water in the fluid. The concentration of sulfur and the percentage gas in the fluid may be determined simultaneously with the concentration of chlorine.
摘要:
Methods and apparatus are disclosed herein for detecting undesired water flow at an angle to the axis of a well borehole. The borehole envisons is irradiated with 14 MEV neutrons resulting in the in situ creation of the radioactive tracer element N.sup.16 in the flowing water. Two spaced gamma ray detectors are used to sense gamma rays produced by the decay of this radioactive isotope. The distance from the center of each detector to the center of the flowing water is used to establish the angle of flow with respect to the well tool, the linear flow rate of the flow v and the volume flow rate V of the undesired water flow.
摘要:
Measurement of the linear flow velocity and volume flow rate of undesired behind casing water flow is provided. A well tool having a 14 MEV pulsed neutron source is used to irradiate the earth formations behind well casing with bursts of high energy neutrons. This irradiation activates elemental oxygen nuclei comprising the molecular structure of the undesired flow. Dual spaced gamma ray detectors located above or below the neutron source detect the decay of unstable isotope nitrogen 16 produced by the oxygen activation in the time intervals between the neutron bursts. Background radiation due to prompt N-.sigma. radiation is thus largely avoided. From the detected nitrogen 16 characteristic gamma rays the linear flow velocity of the undesired flow is determined. By combining this with an estimation of the distance R to the undesired flow region from the detectors, the volume flow rate V may be deduced.
摘要:
Methods are disclosed for measuring simultaneously the thermal neutron lifetime of the borehole fluid and earth formations in the vicinity of a well borehole, together with the formation porosity. A harmonically intensity modulated source of fast neutrons is used to irradiate the earth formations with fast neutrons at three different intensity modulation frequencies. Intensity modulated clouds of thermal neutrons at each of the three modulation frequencies are detected by dual spaced detectors and the relative phase shift of the thermal neutrons with respect to the fast neutrons is determined at each of the three modulation frequencies at each detector. These measurements are then combined to determine simultaneously the thermal neutron decay time of the borehole fluid, the thermal neutron decay time of surrounding earth formation media and the porosity of the formation media.
摘要:
An improved multiphase fluid flow meter for fluid which contains gas. It has a full circle loop to subject the flowing fluid to centrifugal force, and it can measure the pressure differentials between the center and the outside and inside radii of the loop. Also it can measure the density of the average fluid flowing, plus the density of a continuous sampling of the gas and of the liquid constituent of the fluid.
摘要:
An underground logging tool is equipped with a gamma ray detector encircled by a rotatable shield featuring a collimator slot. After the fluid in a formation is activated by a neutron source, the detector is used to obtain radiation count information as a function of horizontal direction as the shield is rotated. Comparison of count rate data as a function of the shield slot orientation gives information concerning the direction of the formation fluid flow. Measurements at different time intervals following the activation of the fluid, made with the shield retracted from the detector, may also be interpreted in terms of speed of horizontal fluid flow past the tool.
摘要:
Measurement of the distance from a gamma ray detector to a gamma ray source for location of a channel of undesired behind casing water flow in a producing well is provided. Coaxially aligned dual cylindrical gamma ray detector crystals are used at one or more longitudinally spaced locations in the borehole to detect the characteristic gamma rays from the decay of radioactive nitrogen 16 produced by the activation of elemental oxygen nuclei comprising the molecular structure of undesired water flow. The ratio of counts at the outer coaxial detector to those at the inner coaxial detector is then interpreted in terms of R, the distance from the detector to the water flow channel. This distance information may then be combined with the linear flow velocity of such undesired water flow to derive an indication of the volume flow rate V of such flow.
摘要:
Fluid in permeable earth formations adjacent well casing is irradiated with neutrons to form radioactive tracer isotopes in the chemical elements comprising the fluid, typically sodium 24 in saline subsurface formation water, which decays by emission of gamma rays. By measuring the rate of decay of the radioactive isotope, a measure of horizontal fluid flow in the formation is obtained. Manganese, present in the steel well casing, has been found to also respond to the neutron irradiation by forming the isotope manganese 56 which emits gamma rays which interfere with the gamma radiation measurements of the trace element indicative of water flow. A method of measuring horizontal fluid flow while compensating for the presence of manganese 56 gamma rays is disclosed.
摘要:
Methods are provided for locating and measuring the linear flow velocity and volume flow rate of undesired water production behind casing in a producing well operating on gas lift while the well remains in a producing configuration. A well logging tool sized and adapted for passing through production tubing is lowered through the tubing string into the producing zone. The tool contains a source of 14 MEV neutrons and two longitudinally spaced gamma ray detectors. The detector may be placed alternately above or below the neutron source on the tool while maintaining the same source to detector spacing. With the well on production under gas lift the earth formations behind the casing are irradiated with 14 MEV neutrons, either continuously or in bursts, to activate elemental oxygen nuclei comprising the molecular structure of the undesired water flow. The decay of unstable isotope nitrogen 16 produced thereby is detected by the detection of its characteristic gamma rays at the dual spaced detectors. These measurements may then be interpreted in terms of the linear flow rate and volume flow rate of the undesired water flow.