摘要:
A method of analyzing a subterranean formation is disclosed. A first signal is transmitted from a transmitter to the formation and a second signal which is a reflection of the first signal is received. A third signal, which is the second signal reversed in time, is then transmitted to the formation. A fourth signal which is a reflection of the third signal from the formation is then received and monitored.
摘要:
An electromagnetic perforation device for well casings includes a coil disposed around a core carried by a mandrel. The device further includes a power supply coupled to a current supply device, which is coupled to said coil. A stabilizing member extends from the mandrel and spaced apart on the mandrel from the coil core. The electromagnetic perforation device may be positioned in a well casing, and the current supply device may rapidly supply a current to the coil to created an electromagnetic field in the coil and simultaneously induces a magnetic field in the well casing. The coil, current, and well casing may be selected such that electromagnetic field and the magnetic field produce repulsive magnetic forces that are sufficient to overcome a yield strength of the well casing and perforate the well casing.
摘要:
Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy.
摘要:
In some embodiments, an apparatus (200) includes a tubular to operate downhole. The tubular has a longitudinal axis and has a cutout (210N) that has a direction that is other than 90 degrees to the longitudinal axis of the tubular. The apparatus also includes an antenna (202A) positioned in the cutout of the tubular. The antenna is to perform at least one of a transmission or reception of an electromagnetic signal that has a path that is to traverse a subsurface formation.
摘要:
In accordance with aspects of the present invention, a method of inspecting a well tubular is disclosed. The method utilizes a probe with a transmitter and detectors spaced from the transmitter by at least twice the diameter of the pipe to be tested. In some cases where multi-tubular structures are tested, the probe can include further detectors spaced from the transmitter by at least twice the diameter of the outer pipes as well. The phase of signals detected by the detectors relative to the transmitter are utilized to detect faults in the pipes.
摘要:
An apparatus and a system and a method are provided, to generate a formation model database comprising multiple models, to rotate a downhole assembly that includes a downhole tool comprising at least one antenna pair that determines resistivity data, and to determine resistivity using the at least one antenna pair during rotation of the downhole assembly as part of a downhole operation. During the down hole operation, the method includes receiving the resistivity data; solving for at least resistivity formation parameters using a selected one of the formation models and a selected portion of the received resistivity data; and updating the selected formation model based, at least in part, on the resistivity formation parameters.
摘要:
According to aspects of the present disclosure, systems and methods for measuring fluid resistivity are described herein. An example system may include a non-conductive tube. The non-conductive tube may be filled with a fluid, such as a formation fluid or drilling fluid, whose resistivity needs to be determined. A transmitter may be disposed around an outer surface of the non-conductive tube. A first receiver may be disposed around the outer surface of the non-conductive tube, and a second receiver may be positioned within a bore of the non-conductive tube. The transmitter may generate a primary electromagnetic field in a fluid within the tube, which may in turn generate an eddy current and a secondary electromagnetic field. The first and second receivers may be used to identify the eddy current and the resistivity of the fluid.