Computer-Based Downhole Data Acquisition and Transmission in Well Testing

Abstract

Abstract Data acquisition techniques for computer-based systems are discussed for making continuous pressure, temperature and flow measurements. To ensure that the data faithfully represent the essential signal content over the time interval of interest, the important considerations for each system are measurement resolution, signal bandwidth, sampling, filtering and aliasing. Key data transmission techniques are discussed, starting with downhole recorders that must be hauled out of the hole for data retrieval, to telemetry systems for sending real-time or bulk data transmissions to the surface. The important issues for downhole recorders are storage media and capacity. For signal transmission systems, the issues are information modulation, data and error rate, and signal-to-noise ratio.