LWD sonic tool transmission Technical Overview
Sonic logging while drilling data capacity, while taking into account the needs and real-time resolution, which gives the transmission and storage of data has brought great challenges. Measured in a differential information transmission carrier, drilling data transmission can be divided into the following types, the main difference in the performance of various data transmission techniques in data transmission rate and two-way communication capabilities ground and underground.
1, mud pulse transmission technique
mud pulse transmission technique is a data transmission during drilling is currently widely used, which can reach the maximum transfer rate of 4 ~ 10 bit / s, in some extent to meet the needs of real-time data transmission .
2, the electromagnetic transmission technology
3, the drill pipe transmission technology intelligent
intelligent transmission rod drilling theoretical data transfer rate of up to measure 2 M bits / s.
4, optical transmission
fiber telemetry data can be transmitted per second, a rate of about 1Mbit / s,
5, acoustic transmission technique.
NAND FLASH chip using a non-volatile data storage, proper design of the interface circuitry and NAND FLASH memory of the program, to achieve a sonic logging while drilling data storage function
wherein the low mud pulse telemetry data rate is an adverse effect is to reduce the drilling progress, increased operating costs. It is necessary to make improvements in this regard. To improve the quality and efficiency of data transmission with the sonic drill logs, from home and abroad to study new delivery vehicles and reduce the volume of both made a great effort. Among them, foreign significant progress has been made on improvements in these two areas. They require real-time processing of acoustic information transmitted to the surface through mud pulse away, and the processing results and a large number of the original waveform data is temporarily stored in a memory efficient thus reducing the amount of transmission.
