Published by the DTI Oil & Gas Directorate for the reservoir engineering and IOR community in the UK.
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IOR related projects and facilities at the Department of Petroleum Engineering, Heriot-Watt University

Brian Smart of the Department of Petroleum Engineering at Heriot-Watt University describes the IOR-related capabilities of the Department, which is soon to become The Heriot-Watt Institute of Petroleum Engineering. (brian.smart@pet.hw.ac.uk)

Introduction
Since 1975, the Department of Petroleum Engineering at Heriot-Watt University has been heavily involved the development and delivery of training and research programmes relevant to the needs of the international petroleum industry. Our Research activity was awarded the highest (5*) grade in the most recent government Research Assessment Exercise, confirming 10 years of internationally-rated research performance. Our staff and student statistics are: Senior Staff 22, Research Staff 30, Technical and Administrative Staff 40, Postgraduate Research Students 40 and Postgraduate Course Students 50. We are housed in 5 adjacent buildings with a total floor space exceeding 5,000 m2. Soon we will become The Heriot-Watt Institute of Petroleum Engineering and this change reflects the size and international nature of our research and lifelong learning activities. A considerable proportion of the current research in the Department is on Improved Oil Recovery either directly, e.g. WAG, gas injection etc.), or indirectly in that it is concerned with improved reservoir characterisation. This will also be the case in the new Institute.

Modern, well equipped laboratories cover many aspects of Petroleum Engineering research including specialised production chemistry and formation damage laboratories, a major rock mechanics facility, and novel core magnetics equipment. Pore scale research benefits from access to a new environmental scanning electron microscope which allows observation of untreated and 'wet' specimens. Some pieces of apparatus are unique, including high pressure micro-model visualisation facilities, our HPHT PVT cells with in situ properties measurements and true tri-axial rock mechanics cells.

Computers play an important role both in research and teaching and the Department has more than 50 Unix workstations and 250 personal computers, staff and students have access to two compute nodes with parallel processing and powerful graphics capability. Industry standard software is readily available to enable teachers, researchers and students to tackle the complex science and engineering problems associated with the exploitation of petroleum resources. This includes significant suites of software by Fairfield, Schlumberger, Geoquest, Landmark and EPS, plus Ansys, Crystal Ball, GoCad, Geolog, GMA, IRAP/RMS, RC2, Que$tor, STARS, IMEX, Terrastation and others. Some of these packages have been enhanced as a result of research conducted in Petroleum Engineering.

IOR Research
Research projects initiated in Petroleum Engineering address real problems faced by oil companies world wide in the development of oil and gas resources. With significant support from the international oil industry, this activity has flourished and research income over the last six years has exceeded £20 million. Most of the projects are supported by several industrial partners in Joint Industry Projects (JIPs) often in collaboration with public sector funding from the UK DTI and the EPSRC. Petroleum Engineering is a multi-disciplinary activity and a particular strength of the Department is that it can combine the relevant engineering and geoscience skills along with expertise in chemistry, physics and maths to tackle the difficult research challenges that now face the industry. Below is a broad review of IOR related projects within the various research groups in the Department.

Reservoir Fluids: This research group forms one of the few international centres active in the measurement and theoretical modelling of phase behaviour and properties of petroleum reservoir fluids. Research areas include reservoir fluid sampling, multiphase equilibria, density, viscosity and interfacial tension of fluids at reservoir and surface conditions. Additional to conventional PVT measurements, tests simulating various reservoir processes such as multiple contact miscibility, swelling, near well gas-condensate inflow and gas cycling are conducted at simulated reservoir conditions. The laboratory uses novel techniques, mostly developed in-house, to measure in-situ properties and composition of all fluid phases at equilibrium conditions. Dynamic phase behaviour studies are also conducted using slim tube displacement. Much of the experimental and modelling work in this group is concerned with IOR by gas injection, depressurisation and WAG related processes.

Hydrocarbon Recovery Mechanisms: This group investigates various hydrocarbon recovery mechanisms to improve the current understanding of the IOR reservoir processes and produces information required for efficient planning and management of field production. The research areas include flow of gas-condensate near the wellbore, well deliverability improvement, trapping of hydrocarbon by water and its subsequent remobilization by depressurisation, water alternating gas (WAG) injection, miscible WAG and simultaneous injection of water and gas (SWAG) and recovery from naturally fractured reservoirs.
The group uses unique laboratory techniques to investigate experimentally reservoir fluid flow at various scales. High pressure flow visualisation at the pore level is performed in three high pressure micromodel rigs resulting in more understanding of the reservoir processes as well as quantitative information. Four core test facilities operating at simulated reservoir conditions, including X-ray local saturation measurement capabilities, are used to produce field specific and generic data. Mechanistic and numerical modelling of flow through porous media, based on in-house experimental observation and measurements, are conducted to generalise research results.

Reservoir Description and Simulation: Successful exploitation of oil and gas reserves - and the correct targeting of IOR processes - depends upon a good understanding and an accurate description of the reservoir. Research in this area, which is one of the largest in the Department, has thus concentrated on establishing the range of flow-rock physics/rock structure behaviour which can be expected in petroleum reservoirs.

It is concerned with the collection of geometrical and petrophysical data in outcrops around the world, subsurface petrophysical data collection strategies, upscaling flow properties and geological modelling, applications of geomechanical principles, carbonate reservoirs, and geophysical imaging and monitoring. Strong links have been developed with the other research groups within the Department to provide realistic numerical models for engineering studies. In particular, existing geoscience and engineering expertise has been integrated with reservoir geophysics (see below) to create a large multi-disciplinary research group in this important new area. The group has active co-operative research links with other UK, European and US universities.

Reservoir Geophysics: The Reservoir Geophysics group specializes in the processing, interpretation and modelling of 4D seismic data. It has a particular interest in the integration of the seismic with reservoir engineering. Other interests include the development of rock physics for time-lapse analysis and multi-component surveys. Again, the focus and application of the research here is related to IOR.

The group is ideally placed to pursue 4D research due to its unique location within a department which supports a range of complementary disciplines. Its current project portfolio covers the North Sea, the West of Shetlands, and the shallow water Gulf of Mexico. The group also has a strong interest in the seismic description of fractured reservoirs, and has experience with fields in Norway, Italy, the Middle East, and East Texas.

Fundamentals of Flow in Porous Media: More basic research is in progress on the fundamentals of multi-phase flow in porous media and the central focus of this work is in IOR. Network modelling research on the effects of wettability on two phase flow has been active for some time and similar approaches are being applied to the physics of depressurisation and also in the modelling of gas injection processes. In this context, the pore scale modelling of three phase flow in mixed wet systems is also being studied in the context of Water-Alternating-Gas (WAG) displacements.

Drilling and Production: Optimum and robust design of wells and associated production systems are central to successful field development and much of our drilling and production research is implicitly oriented towards IOR activities. Several projects are in progress to reduce the operating and environmental costs associated with water handling. The motivation for this effort is the increasing volume of produced water, compounded by the increasingly stringent environmental regulations and the need to improve the cost efficiency of operating practices. These projects include the optimisation of produced water re-injection, investigation of opportunities for down hole separation and analysis of water problems associated with naturally fractured reservoirs. The modelling of intelligent wells and the development of methodologies to quantify their benefit are being studied, so as to aid in the design and specification of remote control and monitoring systems and improve reservoir management and project profitability.

Rock Mechanics: By addressing the manner in which rock reacts to changes in pore fluid pressure and chemistry in geological and real time, rock mechanics can contribute to exploration and appraisal, drilling, production, reservoir engineering and IOR. Stress-related phenomena are being incorporated into coupled rock mechanical and fluid flow simulation to examine reservoir performance on depressurisation. The full integration of rock mechanics within petroleum engineering, named Reservoir Stress State Management, is seen as a primary objective, and comprehensive laboratory and modelling facilities have been established to enable this. Stress sensitive, forward modelling will contribute in future to assessing IOR projects.

Production Chemistry and Hydrates: Although not strictly IOR, a large experimental and modelling group is working in the area of scale prevention and flow assurance. An IOR-related a project is in progress on the topic of chemical water control in collaboration with Baker-Petrolite. This aims to understand the basic processes involved in water shut off and to develop understanding, products and software tools which will improve the field design of these treatments. Also, The Centre for Gas Hydrate Research at Heriot-Watt University addresses various aspects of gas hydrate research, including: avoiding gas hydrate problems in deepwater drilling and production, design and testing of low dosage hydrate inhibitors and the natural occurrence of hydrates in marine sediments.

Recent Initiatives: We will soon be launching a major project sponsored by visualisation technology providers and a geophysics company. This project will develop new techniques, software and methodologies that will further enhance multi-disciplinary team working. The added realism brought to reservoir modelling should, we believe, make another contribution to improving oil recovery.

Finally, we welcome working visits from staff of sponsors and other academics. The recent award of a European Centre of Excellence award even allows us to pay the expenses of certain types of visitors! Check out the EIERO pages on our web site to see if you qualify!

Further Information: if you would like any further information on any of the research discussed here, please contact Professor Brian Smart on +44 (0) 131 451 3128 or brian.smart@pet.hw.ac.uk.

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