Brouard Consulting is a consulting and engineering office founded in 1999 by Benoit Brouard, who received his Ph.D. from Ecole Polytechnique, ParisTech, France. With support from the Laboratory of Solids Mechanics (LMS) at Ecole Polytechnique, this small company has developed worldwide acknowledged expertise in several areas.
Brouard Consulting initially conducted research related to the field of solution-mined caverns. These caverns, which can be several millions of cubic meters large, are leached out from deep salt formations, typically at depths between 200 m and 3000 m. They are designed for liquid or liquefied hydrocarbon storage, or for natural gas storage at high pressure. Strategic petroleum reserves, both in the USA (more than 700 million barrels) and in France, have been created in rock salt. Some of these caverns are used only for salt production in connection with chemical plants for the plastics industry. The caverns also can be used to store huge amounts of energy as compressed air, especially that associated with intermittent energy production of energy from wind power, for instance.
Brouard Consulting is an original and unique company that tackles actual industrial issues at several levels. There is, of course, the theoretical work of modeling all involved phenomena (mechanical, thermal, hydraulic or chemical), which often are coupled, and usually are required to develop numerical programs or to design innovative tests to fit models. Most of these tests then are performed in situ by Brouard Consulting with support from LMS.
From the very large to the very small
In-situ tests usually are characterized by measurements that require great accuracy at unusual sizes and time scales. For instance, salt caverns are among the largest and deepest objects created by human beings. Physical problems such as permeability or thermal expansion, for example, appear at unusual scales. Brouard Consulting and the LMS team have been able to measure accurately in-situ salt permeabilities smaller than 10-20 m². (A rock usually is considered impermeable when its permeability is smaller than 10-18 m².) Brine heating in a large cavern can be very slow — less, say than 10-2 °C/yr and, therefore, can last several decades. Salt creep under a small deviatoric stress is very slow: creep rates of the order of 10-12 s-1 have been measured on salt samples in an isolated mine gallery at extremely stable temperatures. Cavern deformations with amplitudes of 10-9, which could be attributed to natural Earth vibrations, also have been measured during in-situ tests on salt caverns.
For two decades, research carried out by Brouard Consulting and LMS have been presented in more than 100 papers published in international journals and in conference proceedings organized mainly in Europe, North American and Asia. The company also has filed three international patents resulting from its research. Brouard Consulting is solicited regularly for consulting services by large international companies, such as CNPC, which is the second largest Chinese companies and the DOW Chemical Company in the USA.
International team work
Brouard Consulting and Attilio Frangi, Associate Professor at Politecnico di Milano and Assistant Professor at Ecole Polytechnique, have worked together for a long time in the field of software development. A strategic alliance has been signed by Brouard Consulting and RESPEC, one of the leading consulting and services firm in the USA regarding rock mechanics, to seek shared contracts. In 2015, Benoit Brouard served as President of the Solution Mining Research Institute (SMRI), a non-profit worldwide organization based in the USA since the 1960s. SMRI has more than 1500 members from 150 companies in Asia, Australia, Europe, and North and South America. Members are operators, researchers, suppliers, consultants, educators and government regulators involved in the production of salt brine and the utilization of caverns for the storage of oil, gas, chemicals, compressed air and waste.
Promotion of research at Ecole Polytechnique
One of activities developed by Brouard Consulting is the promotion of research conducted by Ayumi Kurosé – a Ph.D. student at Ecole Polytechnique. His work was dedicated to the study of earthquake impacts on underground structures such as tunnels or wells. A software program has been developed by Brouard Consulting and Ayumi Kurosé for the Japan Nuclear Cycle, which is the Japanese agency in charge of radioactive waste disposal. Another project for TOTAL in France was dedicated to potential effects of earthquakes on wells at Lacq (gas production) and Rousse (CO2 storage) facilities.
From Paris to Borneo
Over the past few years, Brouard Consulting and LMS have developed, in conjunction with TOTAL, a new type of in-situ rock-permeability test — WTLog is designed for low-permeability rock in the context of tight gas reservoirs. The idea for this new test came from experience gained in the field of tightness tests for underground storage of hydrocarbons in salt caverns. Theoretical studies were carried out first, followed by filing for a worldwide patent. Three field tests have been performed. The first took place in 2008 in Patagonia, Argentina; the second was in Lorraine, France; and the third, in March 2010, took place in Tambora, Borneo Island, Indonesia. The last is one of the most active TOTAL facility for gas production.
From gas production to drinkable water storage in dry areas
WTLog initially was developed to improve detection of gas reservoirs. Another potential application is characterization of the permeability of overburden layers — not only for waste disposal, but also for seeking for water-bearing strata that could be used to store potable water in dry areas.