Improving reservoir management

Lead Research Organisation: University of Cambridge
Department Name: Engineering

Abstract

Existing methods (seismic and electromagnetic) suffer from serious limitations in their ability to provide continuous, low cost data that can be interpreted to determine water location, volume, and movement throughout a reservoir. Seismic surveys typically require a surface generated signal for deep reservoir phase definition which is costly and in some cases difficult or impossible to obtain. Also, time based (4D) seismic must image phases (to contrast gas versus water acoustic velocity) and does not proportionately see varying volumes. Conventional EM has sensitivity to conductivity changes within the reservoir but only provides information where there are conductivity contrasts such as saline formations, but not depleted reservoirs. Development and commercialization of a robust miniaturised gravity sensor would address these limitations and provide a step change in subsurface verification and monitoring capability. Gravity has inherent advantages to seismic and EM. The gravity signal is always present and does not require a source to generate a response. Also, by detecting differentials in mass or density, gravity offers complementary and independent measures to seismic (which measures acoustic velocity) and EM (which measures differential resistivity). The combination of 4D seismic plus gravity will result in reduced error and improved seismic interpretations. Unlike EM, gravity is deep reading - able to penetrate up to 2000'. Gravity, and in particular MEMS technology, is lower cost (only a few pounds per sensor). MEMS technology also offers other distinct advantages for wellbore deployment, including ease of miniaturizaton and packaging and flexibility on orientation. Because of these attributes, the MEMS gravity sensor is the optimum technology to underpin a system of periodic or low cost permanent sensor arrays in wellbores. This project aims to pilot the development of a new MEMS gravity tool for reservoir imaging.

Planned Impact

Following protection of intellectual property generated through the project, the results will be disseminated to the academic community through leading international conferences and journals.

The sensor aspects of the technology will deal with issues underlying the interaction of noise and non-linear processes in microelectromechanical devices, and approaches to improving long-term device stability by compensating for bias drift and temperature effects. Issues underlying robustness of the device to high temperature environments will be addressed. Additionally, elements related to sensor calibration and data conditioning will be pursued within the University environment. These aspects will be disseminated through publication.

There will be wide dissemination of the projects' results to researchers in oil companies familiar with surface gravity surveys who will be interested in evaluating the detailed performance of the sensors in the Cornwall test. As the tool is developed, the academics will also explore making elements of the tool available to other user communities e.g. researchers engaged in the field of CO2 storage monitoring and researchers engaged in earthquake seismology.

Academics in the microsystems (MEMS) area will be immediate academic beneficiaries though user communities including those in broader geophysics and environmental monitoring fields will also benefit from the results.
 
Description 1. A batch-manufacturable approach to wafer-scale fabrication of high accuracy MEMS sensors with high yield.
2. The demonstration of MEMS gravity sensors with < 10 nano-g stability.
3. The development of electronics interfaces for resonant and mode-localised MEMS sensors.
Exploitation Route These sensors could be applied to areas outside of the oil and gas area including (1) surveying buried underground infrastructure, (2) monitoring groundwater saturation, (3) monitoring buried CO2, and (4) detecting tunneling activity. Follow-on grant applications will be submitted to more substantially develop these and other applications.

Academics in the MEMS field will benefit from our findings on (1) MEMS accelerometers and gravity sensors, (2) interface electronics for high accuracy resonant sensors, (3) applications of gravity mapping to the oil and gas and related areas.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Energy,Environment

 
Description Technologies developed under this award have been licensed to Silicon Microgravity Ltd., a Cambridge University spin-off, developing borehole gravity sensor technology for water flood front monitoring. See http://silicong.com for more information about Silicon Microgravity Ltd.
First Year Of Impact 2016
Sector Energy
Impact Types Economic

 
Description DSTL Proof-of-Concept Research Funding
Amount £90,000 (GBP)
Organisation Defence Science & Technology Laboratory (DSTL) 
Sector Public
Country United Kingdom
Start 01/2018 
End 09/2018
 
Description Industrial partner 
Organisation BP (British Petroleum)
Country United Kingdom 
Sector Private 
PI Contribution The development of MEMS technology for borehole gravity.
Collaborator Contribution A technical team within BP advise on field deployment and technical use cases for the ongoing technology and participate in project review meetings.
Impact Silicon Microgravity (silicong.com) is a Cambridge University spin-off company that arose from the collaborative work conducted together with BP pre-dating this award. Specific outcomes under this award are under development as this project is still live.
Start Year 2009
 
Description Industrial partner 
Organisation Silicon Microgravity Ltd.
Country United Kingdom 
Sector Private 
PI Contribution This project involves a collaboration with Silicon Microgravity Ltd. who are leading a related Innovate UK grant award on Reservoir Management. The Cambridge University team has contributed to the design and characterisation of MEMS sensors, and design and manufacture of the front-end electronics and thermal control systems for a new gravity tool being built by Silicon Microgravity Ltd.
Collaborator Contribution Silicon Microgravity are contributing towards the construction of a new borehole gravity tool. They have also contributed towards the fabrication of MEMS sensors through an external foundry and system build and integration tasks required to assemble fabricated sensors into the tool.
Impact This project is still live and joint outcomes are under development.
Start Year 2015