A*STAR’s Institute of Microelectronics, based in Singapore, signed an agreement to collaborate with Petroleum Geo-Services (OSE:PGS), to develop a high performance MEMS-based sensor for deep sea seismic oil and gas exploration. PGS is a geophysical company headquartered in Oslo, Norway. The MEMS sensor is targeted for incorporation into a PGS commercial streamer system, and will be used to acquire more precise seismic data during seismic survey to locate and estimate the size of offshore oil and gas reserves. The streamer systems are towed behind large ships.
Schematic illustration of a ship towing a large streamer spread with deep towing depth.
The collaboration leverages IME’s experience in designing high performance MEMS sensors, MEMS process platform and in-house packaging capability, and PGS’s expertise in seismic exploration. The project will demonstrate a MEMS sensor and provide guidelines for the packaging and integration with ASIC in the next phase.
“Collaborating with an industry leader provides an opportunity for us to further our research in sensing technology for oil and gas applications,” said Prof. Dim-Lee Kwong, Executive Director, IME. “IME’s integrated capabilities and deep understanding of different sensing technologies in MEMS will enhance our partner’s technology development capabilities and shorten the product development time.”
The oil and gas industry uses seismic imaging to provide 3-dimensional images showing the locations of oil and natural gas deposits. Imaging accuracy is critical to determining the optimum location for drilling to increase extraction efficiency. Two critical needs for improving image resolution and fidelity above today’s results are increasing the spatial density of sensors deployed in the field and generating ultra low noise measurements in a wider frequency band.
One of the advantages that MEMS accelerometers have over geophones is the flat frequency response at low frequencies. Unlike geophones which are velocity sensors and operate above their resonance frequencies, accelerometers operate below their resonance frequencies. The small size and lower power consumption of the sensor nodes will significantly reduce the cost of large scale deployments, enabling data from more channels to be collected, thus increasing the channel density in any given survey.
In earlier work between Shell and HP (unrelated to the A*Star/PGS announcement), a MEMS sensor was fabricated from three separate single crystal silicon wafers bonded together and singulated into a small vacuum encapsulated die. The proofmass was suspended by silicon flexures etched through the center wafer. Electrodes were arrayed on one surface of the proofmass and on the stationary wafer opposite the proofmass. A small gap was maintained between the two wafers.