Abstract:
Various downhole logging tools and methods of using and making the same are disclosed. In one aspect a method evaluating cement bond quality in a well is provided. In a well with a particular casing/tubing configuration, waveforms of acoustic energy returning from the tubing and the casing with the tubing present are recorded. A frequency spectrum from the recorded waveforms is determined. Amplitudes of the returning acoustic energy at one or more preselected frequency(s) of interest of a range of frequencies at which the amplitudes are noticeably affected by cement bond quality for the particular casing/tubing configuration are determined. The determined amplitudes are compared with one or more baseline amplitudes to look for indications of cement bond quality. Other aspects involve time domain analysis.
Abstract:
A caliper-arm-retention mechanism for a caliper tool is disclosed. The retention mechanism includes a selectively movable retention sleeve and a pivot arm that cooperate to constrain relative translational motion between the pivot arm and a caliper arm pivotally engaged with the pivot arm while at the same time allowing relative rotational movement of the caliper arm and pivot arm. The retention sleeve may be selectively repositioned using a threaded nut configured to push the sleeve toward the pivot arm or pull the sleeve away from the pivot arm, depending on the direction of rotation of the nut.
Abstract:
Provided are a probe that enables control of a bending direction and can be simply manufactured, an inspection jig using the probe, an inspection device, and a method of manufacturing the probe. A probe has a substantially bar-like shape extending linearly and includes: a tip end portion, a body portion continuous with the tip end portion Pa; and a base end portion continuous with the body portion. The body portion includes a first connection region having a thickness in a thickness direction perpendicular to an axial direction of the bar-like shape that gradually decreases away from the tip end portion, and a second connection region having a thickness that gradually decreases away from the base end portion. A dimension of the body portion in a width direction perpendicular to the thickness direction is larger than dimensions of the tip end portion and the base end portion.
Abstract:
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.
Abstract:
This invention presents a method for aligning a set of probes in a circuit testing apparatus with a set of pads of a circuit under test and the apparatus designed according to this method. The alignment includes the steps of selecting a first group G1 of probes from the set, such that all probes in group G1 have the same tip length L1 and the same beam length L2, and mounting each probe of group G1 on a first mounting block which has a first through-hole for each probe and a first removable portion which includes the first through-hole. During the mounting step the tip portion is placed in the through-hole, the mounting portion is attached to the first mounting block and the first removable portion is discarded. Then, a second mounting block is placed on the first mounting block and a second group G2 of probes selected from the set is mounted it in the same manner as group G1 on the first block. The blocks are aligning on top of each other by using guide holes and positioning holes in conjunction with a corresponding vertical fixing pin and a tiltable positioning pin.
Abstract:
The invention presents a method and a correspondingly designed probe for achieving uniform stress distribution when experiencing deflection. The probe has a top edge, a bottom edge, a tip, and a beam portion defined by selecting an inflection point along the top edge, such that the beam portion is contained between the tip and the inflection point, and the bottom edge below the beam portion is approximately straight, while the curvature of the top edge of the beam portion is fitted to a parabola. The tip has an outer edge, an inner edge, and a point of contact at the location where the outer and inner edges join. The inner edge is approximately straight while the curvature of the outer edge is fitted to a second parabola. The probe is preferably mounted in a support structure having a groove for receiving the probe such that the beam portion is free to move vertically in the groove and constrained laterally to prevent side-buckling.
Abstract:
An embodiment of the present invention is a probe membrane with a center contact bump area and a plurality of signal connection sections separated by triangular reliefs in the membrane and terminating in a tangential row of contacts for wire bonding to a probe card. The system of triangular reliefs in the membrane allows the membrane to be puckered up such that the center contact bump area is raised approximately ninety mils above the general plane of the probe card. When the membrane has been fixed in its puckered up position, the triangular reliefs in the membrane form several radial rectangular slits. A translator gimbal attached to the center of the membrane provides stability and contact force for the contact bumps to a DUT. Areas of transparency in the vicinity of the contact bump area allows a user to view the I/O pads of a DUT for alignment with the contact bumps in the membrane.
Abstract:
A sensor comprising three electrodes forming two electrode pairs, each pair having a gap between the electrodes, is disclosed. An electrically insulating layer is disposed in the gap of one electrode pair. The sensor may include a RC oscillator circuit connected to the electrode pair having the insulating layer such that the electrode pair contributes to the capacitance of the circuit. The sensor may include a power supply connected to the other electrode pair to provide a voltage across and current through material in the pair's gap. The sensor may be disposed in a borehole to allow borehole fluid to enter the gaps and the RC oscillator circuit and power supply may be operated to provide a measure of capacitance and resistance characteristics of the borehole fluid.
Abstract:
A caliper-arm-retention mechanism for a caliper tool is disclosed. The retention mechanism includes a selectively movable retention sleeve and a pivot arm that cooperate to constrain relative translational motion between the pivot arm and a caliper arm pivotally engaged with the pivot arm while at the same time allowing relative rotational movement of the caliper arm and pivot arm. The retention sleeve may be selectively repositioned using a threaded nut configured to push the sleeve toward the pivot arm or pull the sleeve away from the pivot arm, depending on the direction of rotation of the nut.
Abstract:
A tool for evaluating the internal surfaces of tubular is provided, wherein one or more arms extend outwardly from the tool into contact with an inner wall of the tubular, and changes in the dimensions or condition of the inner wall result in changes in the position of the ends of the arms relative to the tool. This motion is converted, through an electromagnetic transducer, into an electrical signal, the amplitude of which falls is maintained as the temperature of the tool changes. In one aspect, the transducer includes a coil and a moveable metal or magnetic element. The coil is powered by a constant current source, and variations in the resistance of the electrical components of the transducer resultingly do not cause fall off of the output signal amplitude.