Apparatus and methods can be implemented to monitor the condition of the production and intermediate casing strings in oil and gas field operations. A series of measurements can be made in a multi-pipe structure and received responses can be operated on by employing a mapping optimization procedure in which a surrogate model is updated. Estimates of one or more properties of the pipes of the multi-pipe structure can be generated using coefficients of the updated surrogate model. Additional apparatus, systems, and methods are disclosed.

A method and device for inspecting marine risers is described. The marine riser is deployed from a floating unit and connected to a lower marine riser package (LMRP) and a blow-out prevention (BOP) stack, and the method comprises: performing a first riser inspection with an inspection tool where the marine riser is in an unconnected well configuration, wherein the inspection tool includes an ultrasonic transducer device, and the first riser inspection comprises: conveying the inspection tool in an internal diameter of the marine riser, detecting information on the marine riser with the inspection tool while conveying the inspection tool through the marine riser, and collecting data with the inspection tool corresponding to the information detected by the inspection tool.

A method and device for inspecting marine risers is described. The marine riser is deployed from a floating unit and connected to a lower marine riser package (LMRP) and a blow-out prevention (BOP) stack, and the method comprises: performing a first riser inspection with an inspection tool where the marine riser is in an unconnected well configuration, wherein the inspection tool includes an ultrasonic transducer device, and the first riser inspection comprises: conveying the inspection tool in an internal diameter of the marine riser, detecting information on the marine riser with the inspection tool while conveying the inspection tool through the marine riser, and collecting data with the inspection tool corresponding to the information detected by the inspection tool.

A downhole electromagnetic logging tool comprises a transmitting system, a magnetic field sensor array and a control module. The transmitting system and the magnetic field sensor array are both connected to the control module. The transmitting system comprises an upper emission coil and a lower emission coil, which are respectively arranged above and below the magnetic field sensor array, for generating magnetic fields of opposite polarities, allowing the magnetic fields to be concentrated at the magnetic field sensor array. A casing generates a secondary magnetic field, which is received by the magnetic field sensor array to complete detection of the casing.

Various downhole logging tools and methods of using and making the same are disclosed. In one aspect, a downhole logging tool for inspecting a well casing is provided that includes a housing adapted to be supported in the well casing by a support cable. A transmitter is positioned in the housing and operable to generate a magnetic field. Plural receivers are positioned in the housing in circumferentially-spaced apart relation and are operable to sense the magnetic field with azimuthal sensitivity. Electronic circuitry is operatively coupled to the receivers to determine a parameter of the sensed magnetic field and determine a characteristic of the well casing based on the parameter.

A method and system may include disposing an electromagnetic (EM) logging tool in a wellbore. The EM logging tool may include a transmitter disposed on the EM logging tool and a receiver disposed on the EM logging tool. The method may further include transmitting an electromagnetic field from the transmitter into one or more, measuring the eddy current in the one or more tubulars with the receiver, and forming an EM log from the plurality of measurements. Additionally, the method may include identifying a representative signature of a collar from the EM log, locating a plurality of signatures that are similar to the representative signature, iteratively locating a collar signature based at least in part on the representative signature, the plurality of signatures that are similar to the representative signature, and a joint length; and displaying a depth for each of the one or more collars.

A method and system may include disposing an electromagnetic (EM) logging tool in a wellbore. The EM logging tool may include a transmitter disposed on the EM logging tool and a receiver disposed on the EM logging tool. The method may further include transmitting an electromagnetic field from the transmitter into one or more, measuring the eddy current in the one or more tubulars with the receiver, and forming an EM log from the plurality of measurements. Additionally, the method may include identifying a representative signature of a collar from the EM log, locating a plurality of signatures that are similar to the representative signature, iteratively locating a collar signature based at least in part on the representative signature, the plurality of signatures that are similar to the representative signature, and a joint length; and displaying a depth for each of the one or more collars.

A measuring device for measuring a hole in the ground having at least one measuring probe having at least one measurement signal transmitter to transmit a measurement signal, at least one measurement signal receiver to receive the measurement signal reflected on a wall area of the hole, and an evaluation unit for determining a wall distance between the measurement signal transmitter and the wall area of the hole, wherein a measuring distance based on an assignment rule can be assigned to the received, reflected measurement signal. A calibrating device having at least one calibration element. The measurement signal transmitter transmits a calibration signal, which can be reflected on the calibration element, wherein the measurement signal receiver receives the calibration signal reflected on the calibration element. The evaluation unit changes and calibrates the assignment rule based on the calibration signal reflected and received by the calibration element.

Systems, devices, and methods for estimating a value of a parameter of interest of an earth formation intersected by a borehole. Methods include conveying a carrier in the borehole having disposed thereon an acoustic imaging tool including at least one convex linear phased array module, each of the at least one module comprising a rigid shell forming a compartment containing a piezoelectric component array; using the acoustic imaging tool to take acoustic measurements of the borehole; and using the acoustic measurements to estimate at least one parameter of interest. Each module may be self-contained. The tool may include a plurality of modules circumferentially arrayed about a portion of the acoustic tool. Methods include individually removing one selected module from the acoustic tool. Methods may include selecting an outer tool diameter the same as an inner borehole diameter borehole and selecting a maximum number of modules fitting the outer tool diameter.

In accordance with embodiments of the present disclosure, a drilling system includes a roller cone drill bit having a roller cone and at least one antenna loop disposed in the roller cone for detecting magnetic or electromagnetic waves indicative of a target, a resistivity, or a boundary of the subterranean formation, man-made structure, or object. The drilling system may utilize the antenna loop to determine resistivity measurements of a subterranean formation through which the drill bit is being drilled. The location of the antenna in the roller cone may enable increased look-ahead and look-around measurements. In addition, the location of the antenna in the roller cone may facilitate anisotropic resistivity measurements to aid in steering the drill string into a desired portion of the subterranean formation.