Abstract:
Methods and related systems are described for the detection of nuclear radiation. The system can include a tool body adapted to be deployed in a wellbore and a scintillator material that intrinsically generates radiation. The scintillator material is mounted within the tool body. A photodetection system is coupled to the scintillator material, and mounted within the tool body. Features in a spectrum associated with a scintillation material's intrinsic radioactive decay are used for the determination of one or more parameter's of the response function of the radiation detector system.
Abstract:
An antenna 3 of an electromagnetic probe used in investigation of geological formations GF surrounding a borehole WBH comprises a conductive base 31 and an antenna element 32. The conductive base 31 comprises an opened non-resonant cavity 33. The antenna element 32 is embedded in the cavity 33 and goes right through the cavity. The antenna element 32 is isolated from the conductive base 31. The antenna element 32 is coupled to at least one electronic module via a first 34A and a second 34B port, respectively. The electronic module operates the antenna so as to define either a substantially pure magnetic dipole, or a substantially pure electric dipole.
Abstract:
An apparatus for investigating a geological formation surrounding a borehole including a logging tool moveable through the borehole, an electromagnetic probe 1 including a pad 2 mounted on the logging tool for engagement with the borehole by a wall-engaging face of the pad, at least one transmitting antenna TxA, TxB mounted in the wall-engaging face, and a plurality of spaced receiving antennas RxA, RxB mounted in the wall-engaging face spaced in relation to the transmitting antenna TxA, TxB. At least one of the antennas RxA, RxB, TxA, TxB is an open-ended antenna forming a substantially pure electric dipole normal to the pad face and wherein the first transmitting antenna of the at least one pair of transmitting antennas is positioned above the plurality of spaced receiving antennas and the second transmitting antenna of the at least one pair of transmitting antennas is positioned below the plurality of spaced receiving antennas.
Abstract:
Methods and related systems are described for the detection of nuclear radiation. The system can include a tool body adapted to be deployed in a wellbore and a scintillator material that intrinsically generates radiation. The scintillator material is mounted within the tool body. A photodetection system is coupled to the scintillator material, and mounted within the tool body. Features in a spectrum associated with a scintillation material's intrinsic radioactive decay are used for the determination of one or more parameter's of the response function of the radiation detector system.
Abstract:
An antenna (3) of an electromagnetic probe used in investigation of geological formations GF surrounding a borehole WBH comprises a conductive base (31) and an antenna element (32). The conductive base (31) comprises an opened non-resonant cavity (33). The antenna element (32) is embedded in the cavity (33) and goes right through the cavity. The antenna element (32) is isolated from the conductive base (31). The antenna element (32) is coupled to at least one electronic module via a first 34A and a second 34B port, respectively. The electronic module operates the antenna so as to define a simultaneously superposed pure magnetic dipole and pure electric dipole.
Abstract:
A probe for measuring electromagnetic properties of a subsurface formation includes a pad having a face adapted for engagement with a borehole wall, a pair of transmitting antennas, and two pairs of receiving antennas. The transmitting antennas and receiving antennas are mounted in the face of the pad, and each of the two pairs of receiving antennas include a first and second antenna distributed on opposite sides of the pair of transmitting antennas. The probe further includes an electronic arrangement having a transmitter module and a receiver module. The transmitter module is arranged to operate the pair of transmitting antennas in either a broadside mode or an endfire mode by applying an excitation signal modulated by two or more frequencies, and the receiver module is arranged to determine an attenuation and a phase shift of each reception signal provided by each receiving antenna relatively to the excitation signal.
Abstract:
A well logging instrument includes an instrument housing to traverse a wellbore penetrating subsurface formations. An electrically operated energy source that emits ionizing radiation is disposed inside the housing. An insulating sleeve is disposed between the energy source and an interior wall of the housing. The insulating sleeve comprises a thin dielectric film arranged in a plurality of tightly fitting layers of dielectric material disposed adjacent to each other and successively. A thickness of each layer and a number of layers is selected to provide a dielectric strength sufficient to electrically insulate the energy source from the housing and to provide a selected resistance to dielectric failure resulting from the ionizing radiation.
Abstract:
An electromagnetic probe 1 measures the electromagnetic properties of a sub surface formation GF in a limited zone surrounding a well-bore hole WBH. The well-bore hole is filled with a well-bore fluid DM. The probe comprises a pad 2 having a first face defining a first area arranged to be positioned in contact with a well-bore wall WBW. The probe 1 further comprises: at least two transmitting antennas 4A, 4B defining a central point CP between them, each antenna being spaced from a distance do from the central point, and at least a first 5A, 5B and a second set 5C, 5D of receiving antennas, each set comprising a first receiving antenna 5A; 5C and a second receiving antenna 5B; 5D, the first receiving antenna being positioned on one side of the transmitting antennas and the second receiving antenna being positioned on other side of the transmitting antennas so that each set encompass the transmitting antennas 4A, 4B.
Abstract:
A well-logging tool may include a sonde housing and a radiation generator carried by the sonde housing. The radiation generator may include a generator housing, a target carried by the generator housing, a charged particle source carried by the generator housing to direct charged particles at the target, and at least one voltage source coupled to the charged particle source. The at least one voltage source may include a voltage ladder comprising a plurality of voltage multiplication stages coupled in a uni-polar configuration, and at least one loading coil coupled at at least one intermediate position along the voltage ladder. The well-logging tool may further include at least one radiation detector carried by the sonde housing.
Abstract:
A well-logging tool may include a sonde housing, and a radiation generator carried by the sonde housing. The radiation generator may include a generator housing, a target carried by the generator housing, a charged particle source carried by the generator housing to direct charged particles at the target, and at least one voltage source coupled to the charged particle source. The at least one voltage source may include a voltage ladder comprising a plurality of voltage multiplication stages coupled in a bi-polar configuration, and at least one loading coil coupled at at least one intermediate position along the voltage ladder. The well-logging tool may further include at least one radiation detector carried by the sonde housing.