Henri Darcy (not D'Arcy please - even though it was likely his ancestor's pre-French revolution name) was a civil engineer born in Dijon, capital of Burgundy, in 1803. After studying engineering in Paris’ most prestigious institutions, he became civil engineer of the city of Dijon. There, he engineered a 12km underground waterway, from the Rosoir spring to the city. The water arrived at a 2,300m3 storage place and at a rate of 8,000 litres a minute. The storage was next to the city that counted then 29,000 inhabitants. Thanks to this work, Dijon was one of the first city in Europe, along with Rome to enjoy a public water network.
In 1846, in recognition of his work, the city of Dijon awarded Henri Darcy a free connection for life to the public water supply system. Mr. Darcy did not enjoy free water very long because he was moved to Bourges in 1848 for political reasons. Soon after, he was appointed General Inspector of Public Civil Works ("Inspecteur Général des Ponts-et Chaussées") in Paris.
In 1856 - three years before Colonel Drake travelled to Titusville – Henri Darcy published an impressive book (> 600 pages) about the water fountains in the city of Dijon where he was working for the public water network: "Fontaines Publiques de la Ville de Dijon, Exposition et Application des Principes à suivre et des Formules à Employer dans les questions de Distribution d'eau".
In the appendix D (page 559 to 603), Henri Darcy recounts that he studied different filtration systems used to supply water to large communities in the UK and in the city of Marseille. Darcy’s concern is not only filtration quality, but also filtration rate to properly size installations to public demand.
Henri Darcy ran some experiments using sand filters and showed (p .570) that for a given filter, filtration rate is proportional to the open surface and pressure differential across the filter, and inversely proportional to the sand pack thickness. Darcy calls k a coefficient related to the sand permeability, its ability to filtrate water. The equation becomes Q = ks/e * (DP) .
(Darcy notes that to clean the sand filter, it is sufficient to remove 1 or 2 cm on top of the pack. He does not mention skin, but this is close, at least when applied to injector wells).
Henri Darcy says that he developed this equation after a series of experiments that he conducted with another engineer, Charles Ritter, at the Dijon’s hospital where they built a specific instrument. The apparatus was a 2.50m vertical pipe of 0.35m internal diameter. They placed a screen of negligible pressure drop at 20cm from bottom. They installed mercury pressure gauges on both sides of the sand packs made of calibrated material and of 38% porosity. The experiment performed in October and November 1855 consisted in recording the water flow rate through the apparatus and the pressures for different sand pack thicknesses.
The result was that the rate was a linear function of the pressure differential for a given sand pack, and inversely proportional to the sand column height when a similar sand was used (p. 593). In February 1856, Mr. Ritter modified the setup to confirm the findings using a different exit pressure than atmospheric pressure.
Interestingly enough, Darcy extends his concern to a wider problematic than conventional filtration. Because the water is supplied by springs that often result of seepage through permeable soil, he extrapolates his results into a law that can determine the spring rate decline from the highest spring output rate observed and with time and rainfall pattern, in line with his problematic of providing enough water to supply a large city.
This being said, my feeling is that Henri Darcy may have also been inspired if not emulated by another fellow civil engineer turned economist, Jules Dupuit, who published in 1854 the “Traité théorique et pratique de la conduite et de la distribution des eaux” and in 1863 a brilliant “Etudes théoriques et pratiques sur le mouvement des eaux dans les canaux découverts et à travers les terrains perméables”. Dupuit made also a critical contribution to the Darcy’s equation by linking it to subterranean water movement with conservation of mass. Petroleum history has almost forgotten Jules Dupuit the other brain behind this work.
Anyway, if one day you travel to Dijon, walk the street across the railway station. You will arrive at Place Darcy and the "Jardin Darcy" next to it. It is actually where Darcy’s 1848 underground waterway arrives into the vast water basin. The gardens, designed around the basin in 1880, are more famous for its big white bear statue than for the man they were named after. Ask the locals around who they think Darcy was, and you will soon realize that nobody knows. So, after touring the Jardin Darcy, go back to the “café de la gare” and have a glass of Meursault or Gevrey-Chambertin, to the santé of Henri Darcy, mysterious hero of the oil people.
#experiment #YoungProfessionals #Dupuit #reservoir #Darcy #flow #ReservoirDescriptionandDynamics #Students #Dijon #sand #filter #ManagementandInformation #History #permeability #Ritter #DrillingandCompletions #ProductionandOperations