Abstract: An apparatus for measuring gravity acceleration of a drilling tool comprises sensors and a measurement circuit. The sensor comprises a three-axis gravity accelerometer, a reference measurement sensor and a temperature sensor. The three-axis gravity accelerometer measures acceleration component signals in three mutually orthogonal directions, and the reference measurement sensor generates a signal that varies with rotation and is not affected by vibration or shock to serve as a reference signal. The temperature sensor measures the temperature in the apparatus to compensate the temperature effect of the gravity accelerometers. The measurement circuit acquires output signals of the sensors and performs cross-correlation processing on the accelerometer components using the reference signal to extract gravity acceleration signals so as to eliminate centrifugal acceleration, vibration, shock and other interferences generated by rotation.

Abstract: An apparatus for receiving signals in azimuthally acoustic LWD includes a drill collar body, a circuit mounting frame, a receiving transducer, a sealing connector, a preposed processing circuit module, a first receiving signal processing circuit for processing a signal from the transducer, distance detecting sensors, at least one set of plugging assemblies, an electrical connector and a second receiving signal processing circuit for processing signals from the distance detecting sensors. The circuit mounting frame is located inside the drill collar body and connected with the drill collar body. The receiving apparatus integrates a borehole diameter measurement system and an azimuthally acoustic while drilling receiving system on one drill collar.

Abstract: A calibration method under a near-bit wireless short-transmission ground environment includes the following steps: placing an emitter and a receiver, which are connected across a screw, in a container containing a solution, connecting the emitter with the receiver through a copper wire to form a loop of an electric field signal, connecting the emitter with a transmitting circuit to achieve signal transmission, connecting the receiver with a receiving circuit to achieve signal reception, and calibrating an optimal transmitting power and a receiving gain by measuring an amplitude relationship between a transmitted signal and a received signal in a case where resistivity values of solutions are different.

Abstract: In an apparatus for multi-pole acoustic logging while drilling, a N-cycle sinusoidal wave signal is generated by utilizing a signal processor, and amplified into a high-voltage sinusoidal excitation signal by utilizing a power amplifier, and output to a transmitting transducer. The signal processor simultaneously generates an enable signal. The enable signal includes a transient discharge enable signal. The power amplifier is connected with a transient discharge circuit. After the signal processor generates N cycles of a sinusoidal wave, the transient discharge enable signal enables the transient discharge circuit to discharge to release an energy storage current of a power transformer so as to eliminate a high-voltage ringing effect and improve an excitation efficiency of the transducer.

Abstract: A calibration method under a near-bit wireless short-transmission ground environment includes the following steps: placing an emitter and a receiver, which are connected across a screw, in a container containing a solution, connecting the emitter with the receiver through a copper wire to form a loop of an electric field signal, connecting the emitter with a transmitting circuit to achieve signal transmission, connecting the receiver with a receiving circuit to achieve signal reception, and calibrating an optimal transmitting power and a receiving gain by measuring an amplitude relationship between a transmitted signal and a received signal in a case where resistivity values of solutions are different.

Abstract: Digital logic circuitry includes a plurality of logic blocks and memories that execute a method to stitch images. The method includes capturing the images with a plurality of pixel sensors, providing blocks of intensity values captured by the pixel sensors to input/output (I/O) pins of the digital logic circuitry, processing the intensity values with the digital logic circuitry, and stitching the processed images into a stitched image.

Abstract: An apparatus for receiving signals in azimuthally acoustic LWD includes a drill collar body, a circuit mounting frame, a receiving transducer, a sealing connector, a preposed processing circuit module, a first receiving signal processing circuit for processing a signal from the transducer, distance detecting sensors, at least one set of plugging assemblies, an electrical connector and a second receiving signal processing circuit for processing signals from the distance detecting sensors. The circuit mounting frame is located inside the drill collar body and connected with the drill collar body. The receiving apparatus integrates a borehole diameter measurement system and an azimuthally acoustic while drilling receiving system on one drill collar.

Abstract: An azimuthally acoustic while drilling signal receiving transducer encapsulating apparatus includes a drill collar, a receiving transducer, a preposed signal processing circuit and a master control electronics housing. The receiving transducer and the preposed signal processing circuit are encapsulated on a drill collar body individually. The receiving transducer and the signal processing circuit are electrically connected by a sealing electrical connector. The preposed signal processing circuit and the master control electronic housing are electrically connected. The signal processing circuit is preposed in terms of signal processing, and encapsulated on the drill collar, so that signal receiving and processing cable length is shortened and noise interference is reduced.

Abstract: A receiving apparatus for downhole near-bit wireless transmission emission includes an electrical isolation drill collar and an internal electrical isolation short tube. The insulating subs are serially connected and disposed in the middle of the electrical isolation drill collar and the internal electrical isolation sub to realize electric isolation. The electrical isolation drill collar is electrically coupled with the internal electrical isolation short tube through a lantern stabilizer. The receiving apparatus further includes a wireless transmission receiving unit. The electrical isolation drill collar and the internal electrical isolation short tube of the receiving apparatus both have an electrical isolation function. The insulating subs in the electrical isolation drill collar and the internal electrical isolation short tube are non-detachable, and can meet downhole requirements for high torsion and high-pressure sealing property.

Abstract: A wear-leveling NandFlash memory reading/writing method can identify a bad block, avoid the bad block, and equalize writing operations to ensure that all the blocks are identical in number of the writing operations so as to guarantee wear-leveling NandFlash memory reading and writing of the entire memory. This method has characteristics of low computational and small RAM cost, is suitable for the application scenario like operating a single file for a long time with an imbedded system with low cost and poor hardware resource, and can provide a complete file system solution.

Abstract: A apparatus for downhole near-bit wireless transmission includes a bit connecting housing, a mud motor connecting housing, an insulating sub made of an insulating material. The insulating sub is serially connected between the bit connecting housing and the mud motor connecting housing to electrical insulate the bit connecting housing and the mud motor connecting housing from each other. The bit connecting housing and the mud motor connecting housing respectively form an electromagnetic transmitting positive pole and an electromagnetic transmitting negative pole. The mechanical apparatus further includes measurement units, which are configured to acquire parameters measured near the bit and a data transmitting unit, which is configured to realize wireless transmission; and the data transmitting unit is configured to receive and transmit the parameters measured near the bit.

Abstract: A receiving apparatus for downhole near-bit wireless transmission emission includes an electrical isolation drill collar and an internal electrical isolation short tube. The insulating subs are serially connected and disposed in the middle of the electrical isolation drill collar and the internal electrical isolation sub to realize electric isolation. The electrical isolation drill collar is electrically coupled with the internal electrical isolation short tube through a lantern stabilizer. The receiving apparatus further includes a wireless transmission receiving unit. The electrical isolation drill collar and the internal electrical isolation short tube of the receiving apparatus both have an electrical isolation function. The insulating subs in the electrical isolation drill collar and the internal electrical isolation short tube are non-detachable, and can meet downhole requirements for high torsion and high-pressure sealing property.

Abstract: A near-bit constant-power wireless short-distance transmission apparatus includes a transmitting portion and a receiving portion. The transmitting portion is connected to a near-bit measurement sub while the receiving portion is connected to a measurement while drilling system. The transmitting portion processes data received by the bit measurement sub and then transmits it to the receiving portion. The receiving portion further processes the information and then transmits it to the measurement while drilling system. An insulating sub is inserted in the transmitting portion and separates the transmitting portion into a transmitting positive pole and a transmitting negative pole, which become electrically isolated from each other. Another insulating sub is inserted in the receiving portion and separates the receiving portion into a receiving positive pole and a receiving negative pole, which become electrically isolated from each other.

Abstract: A near-bit dynamic well deviation angle measurement apparatus includes a circuit board and 2n+1 accelerometers. One accelerometer is installed in an axial direction of a drilling tool and forms n sets of three-axis orthogonal installation together with other 2n accelerometers. The accelerometer installed in the axial direction measures Az?, and the remaining accelerometers respectively measure n X-axis radial components and n Y-axis radial components corresponding to the n X-axis radial components. A filter and a data processing unit are integrated on the circuit board. The circuit board acquires signals in which the components are eliminated by the accelerators in real time, and further high-frequency vibration and impact interference in the signals are filtered out by using the filter to obtain non-interference gravitational acceleration components Ax, Ay and Az, and further a well deviation angle is calculated.

Abstract: A near-bit tool attitude MWD apparatus includes measurement sensors and a measurement circuit. The measurement sensors transmit measured signals to the measurement circuit, and the measurement circuit processes and calculates the signals to obtain attitude data. The measurement sensors include a triaxial accelerometer, a triaxial gyroscope, a triaxial magnetic sensor and a temperature sensor, the measured data of the triaxial accelerometer, the triaxial gyroscope and the triaxial magnetic sensor are respectively corrected using the measured data of the temperature sensor, a first attitude angle is calculated using the corrected measured data of the triaxial accelerometer and the triaxial magnetic sensor. Quaternions are initialized using the first attitude angle, and the initialized quaternions are subjected to time updating according to the measured data of the triaxial gyroscope, and further an attitude angle is calculated utilizing the updated quaternions.

Abstract: Digital logic circuitry includes a plurality of logic blocks and memories that execute a method to stitch images. The method includes capturing the images with a plurality of pixel sensors, providing blocks of intensity values captured by the pixel sensors to input/output (I/O) pins of the digital logic circuitry, processing the intensity values with the digital logic circuitry, and stitching the processed images into a stitched image.