基于CPLD的高分辨率地层倾角数据采集板的设计

Redesign of the data acquisition board for the high-resolution dip logging tool based on CPLD.

高分辨率地层倾角测井仪-SHDT仪器是用于掌握地下油气藏的延伸范围,了解其分布形态,计算油气储量,经济高效地勘探开发油气藏的一种高效的测井设备。但是进口的SHDT仪器中A/D模数转换芯片采用串行数据输出方式,在市场上很难买到,一旦出现问题仪器便处于瘫痪,为了解决此问题,文章分析了进口SHDT仪器中A/D模数转换电路的特性,利用市场上能够买到的通用的并行输出数据方式的A/D获得串行数据,通过CPLD复杂可编程逻辑器件控制时序配合通用A/D重新设计了数据采集电路板,并能完美地与其他功能模块配合,成功地解决了对难购的串行A/D芯片的依赖问题。

The high-resolution stratigraphic dip logging tool(SHDT) is an efficient logging device,which is used to study the extension of the underground reservoir area and their distribution patterns, calculate the gas and oil reserves, explore and develop the oil and gas reservoir in the economical and efficient way. On the data acquisition circuit board of SHDT, the A/D analog-to-digital conversion chip is a serial data output mode. However, this kind of chip is in short supply, once failed, the SHDT instruments will be forced to stop using. In order to solve this problem, this paper analyzes the characteristics of the import SHDT instruments A/D analog-digital conversion circuit. We use the common parallel output data of A/D to produce the serial data, the data acquisition circuit board is redesigned by fitting the timing which is controlled by CPLD to the common A/D, and it can perfectly match with other functional modules. In this way, It successfully resolve the supply shortage problem of serial A/D chip.