Design And Implementation Of The High-performance Ultrasonic Reflection Logging Instrument Control Section

In the process of oil exploitation, Using the ultrasound reflection logging method can directly observe the cracks of the borehole wall,development of the hole,lithology of the wall and check the casing perforations position, the extent of corrosion, casing deformation and analyze cementing bond quality of the first interface. Ultrasonic television imaging logging instrument and Cementing quality testing instrument are the logging equipments that evolved from the ultrasonic reflection logging technology. However, with the deepening of oilfield exploration and development, it puts forward higher requirements on the two types of instruments that mainly concentrated in the following points:(1) Improving the image quality of ultrasonic TV in heavy mud environment; (2) Reducing the power consumption of the instrument; Enhancing circuit integration; Enhancing the high-temperature characteristics of the instrument; Adapt to the needs of slimhole well logging and logging while drilling; (3) To integrate the two kinds of instruments to the same system that it realize one instrument can not only for wall ultrasound imaging, but also for cement cementing quality evaluation; improving the logging efficiency. Therefore, the study of higher performance logging tool has a very important engineering significance.The main work of this article is aimed at the above requirements that design the control part of the high-performance ultrasound reflection logging equipment. The paper according to the function requirements and technical index of the new instrument that analyzes the working mode and basic timing of the two kinds of instruments and sums up the three basic work timing of the two types instruments. According to the design ideas of hierarchical sequence control, this paper presents the basic control logic timing implementations of the FrameStart, PHOneStart and SampStart. It generates control signals required for each unit module of the instrument that based on this basic timing. On this basis, the paper adopts Actel’s FPGA as the hardware platform that design and realize the control logic module of the ultrasonic reflection logging instrument that based on FPGA.In summary, the article’s main innovation point lies in that:(1)For the issue that ultrasonic television imaging logging imaging effect is poor in the heavy mud environment, the paper designs time-varying gain amplification control logic and solve the TV imaging problems under heavy mud conditions;(2) Based on wavelet inspire thoughts,it designs that logic ultrasonic transmitter circuit based on CMOS switch that controlled by FPGA logic. It has reached the requirement of low efficiency and stable performance and it is advantageous to the relevant processing, extraction of echo amplitude information; (3) implement the TV image and cementing quality testing the two instruments into one.The measured and the experimental results show that: Control logic module has reasonable structure, high level of integration, strong extensibility, low power consumption. It is stable at high temperatures and reaches a predetermined design requirements. Therefore, the results of the research and development of ultrasonic reflection tool has practical reference value.