Chinese Academy of Sciences

Jiansheng Du

Yang Liu

Xinzhen He

Qingyun Di

Wenxuan Chen

Yongyou Yang

Qingbo Liu

Wenxiu Zhang

Zili Wang

Yuliang Wang

Jing Ou

Qijun Xie

Linfeng Hong

Tsili Wang

Xiaolong Li

Qihui Zhen

Hui Wu

Jiwen Xiao

Jian Zheng

Zhongxing Wang

Renzhong Pei

A method of encoding and decoding downlink instructions based on mud flow rate includes an encoding method and a decoding method. The encoding method and the decoding method are configured to transmit and receive instructions by controlling the mud flow rate during drilling process. The method of encoding and decoding downlink instructions based on mud flow rate does not require a fixed threshold of voltage as a judgement standard for '0' and “1” symbols, but uses voltage change rate as a standard for judging the level transition, avoiding decoding failure caused by the inability of voltage sampling values to reach the fixed threshold after well depth is increased.

Method of encoding and decoding downlink instructions based on mud flow rate

A service table for polling data of downhole transmission devices in MWD includes a frame number, a number of data items of a data frame, a number of cycles of the data frame in a polling process, a device address of each of the data items, a measurement parameter, a valid bit number, a valid byte number of the data frame, a total frame number, a total polling frame number H and a total polling frame number L, an error polling frame number H and an error polling frame number L, and a transmission status bit flag. The service table architecture for polling data of a downhole transmission device in MWD has been used in actual drilling devices and has completed field operations for multiple wells. Compared to the simplified service tables in the past, the service table can support multiple downhole transmission devices working simultaneously, which has improved drilling efficiency and saved drilling costs.

Service table for polling data of downhole transmission device in measurement-while-drilling

The present application discloses a carrier wave distortion compensation method for an MWD mud continuous wave system, comprising: in the downhole, modulating the carrier wave according to the transmission data to obtain a mud continuous wave signal to be transmitted; transmitting the mud continuous wave signal to the ground via a mud channel; denoising the received pressure signal on the ground to obtain a denoised mud continuous wave signal; performing subsequent processing on the denoised mud continuous wave signal to obtain the final transmission data; and performing downhole distortion compensation before modulating the carrier wave or performing ground distortion compensation on the denoised mud continuous wave signal before performing subsequent processing. The present application reduces the bit error rate of the MWD mud continuous wave system by performing waveform distortion compensation prior to downhole modulation or during performing signal processing on the ground.

Method for carrier distortion compensation in MWD mud pulse telemetry

Disclosed is a synchronization method for an MWD mud pulse telemetry system. The method comprises: determining a synchronous training sequence on the basis of a frame structure of downhole sent data; constructing a correlation between the down-hole sending synchronous training sequence waveform and the uphole synchronous training sequence local waveform by means of the irrelevance of the trigonometric function; and performing correlation calculation on the synchronous training codeword waveform, which is received uphole and is subjected to the first modulation, and the synchronous training sequence local waveform, which is subjected to the second modulation, so as to obtain a correlation curve, and finding a synchronous position by means of the correlation curve.

Synchronization method for an MWD mud pulse telemetry system

The present invention relates to alternating stress fatigue testing equipment. The alternating stress fatigue testing equipment includes a pedestal on which linear guide rails are arranged; a deflection loading device which is arranged on the pedestal and configured to, in response to a clamped to-be-measured object being driven to slide to a first position, enable the to-be-measured object to be bent to a target degree and keep the to-be-measured object after the to-be-measured object is bent to the target degree, wherein the deflection loading device is rotatably connected to the to-be-measured object; two hinged shaft supports which are arranged on the linear guide rails, wherein the hinged shaft supports are symmetrically arranged about a longitudinal center line of the deflection loading device, connected to both ends of the to-be-measured object respectively, and configured to be adjusted obliquely to adapt to the bending of the to-be-measured object to the target degree.

Alternating stress fatigue testing equipment

The present application relates to self-adjusting damping vibration absorbers, in particular to a self-adjusting damping vibration absorber for while-drilling instruments and an adjusting method thereof. The self-adjusting damping vibration absorber includes a vibration monitor and controller tool and a vibration absorber body. The vibration monitor and controller tool is mounted inside the downhole while-drilling instrument, one end of the vibration absorber body is connected to the vibration monitor and controller tool through an insulating connector, the joint is provided with an insulating pad, the other end is connected to a sensor or circuit board tool that needs vibration damping, and the inside of the vibration absorber body is provided with a damping adjustment layer made of an electroactive polymer. By controlling the magnitude of an applied voltage, the damping adjustment can be realized, and the damping adjustment layer has the characteristics of high response speed and high control precision. The self-adjusting damping vibration absorber of the present application can adjust the vibration absorber damping according to the changes of the downhole vibration and temperature, so that the vibration absorber inherent frequency avoids or is far away from the vibration frequency of the downhole while-drilling instrument so as to avoid resonance, and thereby, the vibration absorber achieves the best vibration damping effect.

Self-adjusting damping vibration absorber for while-drilling instruments and adjusting method thereof

The disclosure relates to a fluid pressure measuring device for a measurement-while-drilling tool, which including a first sensor assembly (), a second sensor assembly () and a sealing member (), wherein a mounting groove () is formed on an outer side wall of a drill collar () of a measurement-while-drilling tool; the sealing member () is fixedly mounted on the mounting groove (); a first liquid inlet hole () is formed in the sealing member (); a second liquid inlet hole () communicated with a center flow channel () of the drill collar () is formed in the mounting groove (); a liquid inlet end of the first sensor assembly () is communicated with the first liquid inlet hole (); and a liquid inlet end of the second sensor assembly () is communicated with the second liquid inlet hole ().

Fluid pressure measuring device for measurement-while-drilling tool

A rotary guiding device includes a rotating shaft to rotationally drive a tool head. The rotating shaft includes upper and lower shaft portions, and a steerable portion, the upper shaft portion and the lower shaft portion are steerably connected by the steerable portion. A non-rotating body is mounted on the upper shaft portion, the non-rotating body is substantially non-rotating with respect to the rotating shaft in circumferential direction when the rotating shaft rotationally drives the tool head. The lower shaft portion includes a rib portion coinciding at least partially in axial direction with the non-rotating body. The non-rotating body includes at least three hydraulic driving mechanisms uniformly distributed along its circumferential direction, the three hydraulic driving mechanisms controllably generate radial drive forces respectively, the radial driving forces act on the rib portion overlapping the non-rotating body so the lower shaft portion can be deflectable relative to the steerable portion.

Rotary guiding device based on radial driving force

A hybrid rotary guiding device, includes: rotating shaft, the rotating shaft is used to drive the head of a drill tool to rotate, the rotating shaft includes an upper shaft portion, a lower shaft portion, and a steerable portion, a separation distance exists between the upper shaft portion and the lower shaft portion in the axial direction, the upper shaft portion and the lower shaft portion are steerably connected by the steerable portion; the upper shaft portion is installed with at least three first hydraulic mechanisms, and the lower shaft portion is installed with at least three second hydraulic mechanisms, the second hydraulic mechanism is adapted to drive a pushing member against the wall of the well to guide the head of a drill tool, the first hydraulic mechanism and the second hydraulic mechanism are configured so that the first hydraulic mechanism can drive the second hydraulic mechanism to drive the pushing member. The present invention combines the advantages of directional and push-oriented guidance, the influence of formation properties on the build-up slope is largely eliminated, a higher build rate can be provided, and the demand for energy consumption is greatly reduced.

Hybrid rotary guiding device

A constant amplitude adjusting method and system for pressure pulse of drilling tool including obtaining a current flow velocity value of mud at the rear of a pressure pulse generator in the drilling tool, and sending the current flow velocity value to a controller; the controller compares the current flow velocity value with a preset flow velocity value, and sends an adjustment instruction to the pressure pulse generator according to the comparison result; the pressure pulse generator adjusts the opening degree according to the adjustment instruction of the controller. The adjusting system comprising a pressure pulse generator for generating a pressure pulse wave, and the opening degree is adjustable.

Constant amplitude adjusting method and system for pressure pulse of drilling tool

The invention discloses an anti-rotating device of non-rotating sleeve. The anti-rotating device is connected with the non-rotating sleeve in such way so that the anti-rotating device can transmit circumferential acting force to the non-rotating sleeve, thus the non-rotating sleeve are prevented from rotating, the anti-rotating device comprises an anti-rotating member and a resilient member, the anti-rotating member can move in a generally radial direction of the non-rotating sleeve, and the resilient member acts on the anti-rotating member and provides acting force being substantially radially outward for the anti-rotating member. According to the anti-rotating device of the non-rotating sleeve and a rotary guiding device, on the one hand, bases can be provided for accurate attitude measurement and guiding control, on the other hand, excessively rapid rotation of the two non-rotating sleeve can be prevented only by using one anti-rotating device, and meanwhile the anti-rotating device can further provide guiding driving force based on the minimum structure size.

Anti-rotating device of non-rotating sleeve and a rotary guiding device

The present disclosure relates to a conductive slip ring for logging while drilling (LWD) instrument. The present disclosure utilizes a mechanical conductive slip ring to solve the problems of transmission of electric power and signals between two structures that have relative rotation, and the conductive slip ring has a simple structure, doesn't involve any complex circuit, and has low cost and high reliability. With the conductive slip ring in the present disclosure, there is no power transmission efficiency problem or signal transmission error rate problem. The conductive slip ring has high temperature-resistant, pressure-proof, and vibration-roof abilities, and can be applied widely.

Conductive slip ring for logging while drilling instrument

The present disclosure provides a device for power transmission and signal transfer between the stator and the rotor of a screw drilling tool. The present disclosure can replace the wireless communication technique between the rotary steering tool and the integrated MWD/LWD, omit the upper mud generator above the rotary steering tool, and thereby realize power transmission and signal transfer between the stator and the rotor of the screw drilling tool.

Device for power transmission and signal transfer between stator and rotor of screw drilling tool

The static push-the-bit articulated high-built-rate rotary steerable tool has the main body of a non-rotary measurement and control unit articulated with the main body of a non-rotary actuator, rather than an integral structure. Due to the fact that the drilling tool is easy to bend in a wellbore, the bending stress in an upper portion of the steerable tool is low, and the consumption of the pushing force for bending deformation of the drilling tool is minimized. Since the steering sleeve around the main body of a load-bearing actuator only slides along the well wall in an axial direction without rotational friction there-between, the service life of the steering sleeve is long. Besides, since hydraulic pressure is used instead of pressure difference of mud to act on the pistons to form the pushing force, the pushing force is greatly improved, and the sealing life of the pistons is longer.

Rotary steerable drilling tool and method of control thereof

The present invention relates to the technical field of rotary steerable drilling, particularly to an apparatus for testing the function and performance of a rotary steerable tool in a horizontal or inclined state. The apparatus comprises a rotary steerable tool testing bench configured to provide a horizontal state and an inclined state for a rotary steerable tool so as to simulate a horizontal drilling state or a directional drilling state on the ground; and a rotary steerable tool function and performance testing unit disposed on the rotary steerable tool testing bench to test the function and performance of the rotary steerable tool in the horizontal drilling state or the directional drilling state. The apparatus in the present invention can test the function and performance of a push-the-bit rotary steerable tool under horizontal and inclined conditions on the ground in a lab.

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Beijing, China

Jiansheng Du