Abstract: A downhole drilling system has a downhole motor, a universal-joint assembly having an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: This disclosure provides a downhole drilling system, which comprises a downhole motor, a universal-joint assembly comprising an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: A downhole drilling system has a downhole motor, a universal-joint assembly having an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: A downhole drilling system has a downhole motor, a universal-joint assembly having an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: A push-the-bit rotary guiding device includes a mandrel having a central passage, a sleeve rotatably sleeved outside the mandrel, a plurality of swing ribs circumferentially arranged in an outer wall of the sleeve with an interval, an actuation mechanism for controlling each swing rib to swing respectively, a plurality of detectors for detecting a distance to a well wall in real-time, and a controller for determining whether the actuation mechanism is required to actuate the swing ribs to swing according to the detected distance. Through a real-time detection of the detectors of the push-the-bit rotary guiding device, a well section having an expanded or reduced diameter is detected in time and guiding of the rotary guiding device herein is avoided. The rotary guiding device has advantages of a simple and compact structure, convenient machining, easy assembling, and a safe and highly-efficient operation, and is easy to be popularized and applied.

Abstract: An imaging method and an imaging apparatus based on a magnetic flux leakage testing. The imaging method includes: selecting an imaging region having a corrosion defect on a pipeline to be tested; dividing the imaging region into a plurality of grid areas; scanning by a three-dimensional sensor array the pipeline to be tested so as to obtain magnetic flux leakage testing data; creating a three-dimensional orthogonal coordinate system in the imaging region, defining a first two-dimensional matrix of defect images according to the plurality of grid areas based on the three-dimensional orthogonal coordinate system, and creating a second two-dimensional matrix of magnetic flux leakage signals according to the magnetic flux leakage testing data based on the three-dimensional orthogonal coordinate system; and mapping the second two-dimensional matrix to the first two-dimensional matrix using a pre-trained wavelet neural network so as to image the corrosion defect.

Abstract: A downhole drilling system has a downhole motor, a universal-joint assembly having an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: A push-the-bit rotary guiding device includes a mandrel having a central passage; a sleeve which is rotatably sleeved outside the mandrel; a plurality of swing ribs which are circumferentially arranged in an outer wall of the sleeve with an interval; an actuation mechanism, for controlling each swing rib to swing respectively; a plurality of detectors, which are circumferentially arranged in the outer wall of the sleeve with an interval, for detecting a distance to a well wall in real-time; and a controller, for determining whether the actuation mechanism is required to actuate the swing ribs to swing according to the detected distance. An application method of the push-the-bit rotary guiding device is provided. According to the push-the-bit rotary guiding device, through a real-time detection of the detectors, a well section having an expanded or reduced diameter is detected in time and guiding of the rotary guiding device herein is avoided.

Abstract: This disclosure provides a downhole drilling system, which comprises a downhole motor, a universal-joint assembly comprising an upper universal joint and a lower universal and a connecting rod connecting the upper universal joint and the lower universal joint, and a measurement sub. The measurement sub is disposed about the connecting rod and the connecting rod extends through the measurement sub in a longitudinal direction thereof.

Abstract: The present disclosure relates to a downhole rotating magnetic field generator, wherein a stator assembly is formed by fixedly connecting a guiding stator, windings, and a body together, and a rotor assembly is formed by mounting a turbine rotor and a permanent magnet together. Between the stator assembly and the rotor assembly, sliding bearings are arranged and small mud passages are formed. There is no metal isolation between the rotor and the stator for cutting through the magnetic lines of force, so that the eddy current loss is relatively small. Meanwhile, with mud flowing through the passages as lubricant, overheating of the generator can be prevented and high power output can be ensured.

Abstract: An imaging method and an imaging apparatus based on a magnetic flux leakage testing. The imaging method includes: selecting an imaging region having a corrosion defect on a pipeline to be tested; dividing the imaging region into a plurality of grid areas; scanning by a three-dimensional sensor array the pipeline to be tested so as to obtain magnetic flux leakage testing data; creating a three-dimensional orthogonal coordinate system in the imaging region, defining a first two-dimensional matrix of defect images according to the plurality of grid areas based on the three-dimensional orthogonal coordinate system, and creating a second two-dimensional matrix of magnetic flux leakage signals according to the magnetic flux leakage testing data based on the three-dimensional orthogonal coordinate system; and mapping the second two-dimensional matrix to the first two-dimensional matrix using a pre-trained wavelet neural network so as to image the corrosion defect.

Abstract: The present disclosure relates to a downhole rotating magnetic field generator, wherein a stator assembly is formed by fixedly connecting a guiding stator, windings, and a body together, and a rotor assembly is formed by mounting a turbine rotor and a permanent magnet together. Between the stator assembly and the rotor assembly, sliding bearings are arranged and small mud passages are formed. There is no metal isolation between the rotor and the stator for cutting through the magnetic lines of force, so that the eddy current loss is relatively small. Meanwhile, with mud flowing through the passages as lubricant, overheating of the generator can be prevented and high power output can be ensured.