Data Acquisition And Recording System
E.A. Messana · Offshore Technology Conference · 1979
ABSTRACT A new, low-cost data acquisition and recording system enhances offshore and onshore drilling operations. In terms of both technical performance and cost, the system operates more efficiently than existing systems in the field. The heart of the new system and the key to its high reliability is the complete redesign of surface sensors. These new sensors employ the latest state-of-the-art in electronics and fiberoptics transmission to achieve a high MTBF over similar systems, thus using minimum manpower in field support operations. The system uses a microcomputer to collect data on rate of penetration, difference flow, mud weight, pump pressure, pump strokes, hook load, mud-pit totalization, and rotary rpm. Information is displayed via CRT and hard-copy printout. A 16-bit microprocessor controls the system, and a solid-state ROM memory stores all algorithms and programs. The operator has the ability to control reset alarms and determine limits through the keyboard entry. A modular product design is incorporated into the system, with major components placed in and around the drilling area, eliminating the requirement for a dedicated trailer to house electronics. In addition, the new system meets intrinsic-safety and explosion-proof guidelines, and it is designed in accordance with all government requirements. INTRODUCTION Due to the high cost of drilling operations and the requirement for skilled personnel, it has become cost effective for operators to instrument and monitor surface well operations to increase drilling efficiency, enhance well safety and decrease well drilling costs. Well instrumentation is especially cost effective on offshore platforms and deep land-based rigs where dangerous zones are anticipated. It also has application for wildcat wells where no previous formation data is available. In most cases, well instrumentation is provided by a service company, and a daily rate is established based on the services provided. These services may include:Assisting in locating hydrocarbon and/or inert gas-bearing zones as the well is being drilledDetecting critical changes in the drilling operation (and providing alarms)Providing the latest information on pore and fracture pressure interpretation To accomplish these tasks, data must be gathered from strategically located sensors throughout the drilling operation. Required data falls into these general categories:Geological data--Analysis of cuttings to identify formation tops, to aid wire-line logs and to confirm pressure prediction plotsTotal gas analysis--Automatic cycling through the gas spectrums to report the presence of hydrogen, helium, methane, ethane, propane, isobutane and normal butane in volume percentWell drilling monitoring equipment--Measurement of drilling parameters such as rate of penetration, kick detection, etc. Once data is acquired through the sensor inputs it must be reviewed by service personnel and put in a useful format, for the customer. This is usually accomplished with a computer that is programmed to reduce sensor data, to apply correction or scaling factors, to do the necessary mathematical computations and to format the information for man/machine interfaces, such as CRTs, printers, recorders or remote transmission.