9.4 Object-Oriented Analysis and Design

9.4.1 Design Example – Dipmeter Wireline Logging Tool

This example is concerned with the development of software for a wireline oil well logging tool called a dipmeter.

Figure 9.27: Dipmeter logging tool – system configuration diagram

The purpose of the dipmeter is to extract geological information concerning oil-bearing rock (usually sandstone). In particular, it seeks to define details of the bedding planes in the subsurface formation, as follows:

• Depth of bedding planes in a borehole
• The angle of the bedding planes
• Position of the planes in three dimensions in Earth's coordinates

This information is gathered by drilling a borehole and then running a dipmeter or logging sonde (housed on the end of a wireline cable) up the hole. During the run, a set of electrical sensors (pads) are held in contact with the borehole wall, measuring wall resistivity. As a pad crosses a bed...