Geophysics & Environmental Control :
(G1) - Geophysics & Environmental Control
(G2) - Geophysics & Environmental Control

(G1) - Geophysics & Environmental Control

Session chair: Jan Suski, Schlumberger OFS, France

Speakers:

Jacques Orban, Schlumberger OFS, France
Oil & Gas / Geophysics & Well optimization: Status & Trend in Measurements & Controls

Abstract:
Most of the important new Oil&Gas discoveries are located in remote or offshore deep-water regions of complex geology that makes recovery expensive and technically difficult. Service quality and safety records are key parameters in those risky environments, while environmental impact has to be reduced. The development of these complex reservoirs is only feasible after proper assessment of their potential. Their potential depends on various parameters such as its size, the amount of hydrocarbon in place and the ease of production. In parallel, depletion of mature fields is forcing production down in most OECD countries (United States, Canada, North Sea). However, because of the need to produce locally, there is the need to develop technology for identifying small pockets of untapped reserves, better produce oil & gas and extend life of those fields. Cost of service delivery is a key driver in this highly competitive market.

Seismic prospection determines global parameters of the reservoir, such as extend, general thickness, shape, and depth. Today's seismic acquisition systems consist of large multi-layer synchronized networks of digital high performance sensors. These systems improved the limits of image quality, via reduction of all perturbation effects: for example, each marine component is positioned extremely accurately, via complex feedback navigation system. These systems are based on highly integrated intelligent microsystems, under control of a digital master unit. Additional reservoir information is obtained by logging technique, either via wireline or "Logging While Drilling" conveyance systems. Nuclear & Electrical measurements allow the determination of various formation parameters. High accuracy is obtained after proper correction of various perturbations. These high performances are achieved via the use of integrated system under control of digital units. Furthermore, formation pressure, fluid mobility, fluid composition can be obtained in down-hole conditions by wireline "dynamic testers". These tools are highly integrated electro-hydraulic-mechanical robots operating in harsh environments, and performing high quality pressure and optical measurements.

Today's wells can be drilled following complex trajectories, thanks to "Measurement-While-Drilling" (MWD), "Logging-While-drilling" (LWD) and "Steerable Systems". MWD performed high accuracy surveys transmitted to surface via acoustical telemetry in drilling mud. "Rotary Steerable systems"(RSS) are self-controlled robot capable to drill the hole following a pre-defined trajectory. These measurements and controls technology can be combined to place the "horizontal" wells in optimum position versus the reservoir, for long and high hydrocarbon production.

Measurement and drilling systems have seen drastic evolution in recent years, thanks to high integration between sensors, acquisition electronic, digital control systems. Electro-mechanical robot systems have been introduced recently to perform operation in harsh conditions. More evolution is foreseen in the near future to continue the trend of improvements required for efficient energy supply.

Philippe M. Teillet, Centre for Remote Sensing, Canada
Towards Integrated Earth Sensing: >From Space to In Situ

Abstract:
This paper describes a new initiative called the In Situ Sensor Measurement Assimilation Program - ISSMAP, with the goal of developing new data acquisition strategies and systems for an integrated Earth sensing approach to monitoring remote environments, hazards, disasters, and natural resources. In particular, ISSMAP is taking advantage of the converging technologies of micro-sensors, computers, and wireless telecommunications to design and deploy intelligent sensorwebs for in situ data acquisition.

(G2) - Geophysics & Environmental Control

Session chair: Philippe M. Teillet - Canada Centre for Remote Sensing


Speakers:

Piotr Tucholka, University Paris XI, France
Major challenges For Environmental Studies

Abstract:
This talk will describe the growing necessity for progress in qualitative and quantitative solutions for major and fast changes in global, regional and local environment due to increasing effects of human activity. The addressed factors are ranging from global or continental scale processes like erosion, mineral transfer from continents to marine basins, geochemical and biological factors in carbon dioxide system to local processes like water flow in soils, pollutants and their transfer into aquifers. In numerous cases new approach is necessary to provide reliable information about these processes.

E. Donzier, A.R.H. Goodwin, M. Manrique, Olivier Vancauwenberghe, Schlumberger Doll Research, USA
Resonant MEMS Microsensors for the Measurement of Fluid Density and Viscosity

Abstract:
Resonant MEMS microsensors, based on vibrating plates, have been developed to determine the density and viscosity of fluids. The process used to manufacture the resonant sensors from Silicon On Insulator (SOI) wafers will be described along with the methods adopted to package the MEMS devices. Finite element analysis with ANSYS was used in the design to estimate the device response (vibration modes and frequencies) and to optimize the vibration detection by locating adequately the piezoresistive strain gauges. Measurements of the resonance frequency and amplitude or Q factor are combined with an electromechanical model to determine the density and viscosity of the fluid surrounding the vibrating plate.
Using a resonant MEMS sensor with a plate vibrating in flexion, densities in the range of 1 to 1100 kg/m3, and viscosities in the range of 10 to 1000 ìPa s, were determined for a natural gas, a reservoir oil, and formation water. After a simple calibration of the device by fitting only three adjustable parameters to measurements with argon, these values were found to lie within ±1% for density and ±5% for viscosity, when compared with either accepted literature or experimental values. The reference experimental results were obtained with techniques that utilize principles different from the vibrating MEMS and have quite different sources of systematic error.

Last update - Dec. 14, 2002