01 May, 2009

Cuba Needs Big Scale Exploration

AAPG author pulls data together

 

A personal connection with a legendary geologist Hollis Hedberg triggered Georges Pardo’s personal connection with Cuba – and that bond has led to a new AAPG book on the island’s geology.     

Georges Pardo, left, with Harry Wassall in Nuevitas in Cuba’s Camaguey Province, in 1952. Photo courtesy of Georges Pardo

Georges Pardo, left, with Harry Wassall in Nuevitas in Cuba’s Camaguey Province, in 1952. Photo courtesy of Georges Pardo
Georges Pardo, left, with Harry Wassall in Nuevitas in Cuba’s Camaguey Province, in 1952. Photo courtesy of Georges Pardo

Caribbean geology has always held a charm for Georges Pardo.

For the past 60 or so years, the area has been his professional focus, or at least in the periphery of his attentions.

His interest has resulted in the publication of AAPG Studies 58 Geology of Cuba, due to be hot off the press in time for the AAPG Annual Convention and Exhibition in Denver.

“The Caribbean always has been of great interest to me,” Pardo said. “Throughout my career I have been personally involved with the geology of Barbados, Venezuela, Northwestern Colombia, the Gulf of Mexico and several geophysical transects across the Caribbean.”

Born in Paris to a Venezuela father and a French mother, Pardo’s family moved to Caracas when he was a teenager. Studying toward a geology degree at the Venezuelan Instituto de Geologia, he was encouraged by professor E. Mencher (later of Massachusetts Institure of Technology) to join AAPG as a student member.

“I became an (Active) member in 1945, after joining Mene Grande (the Venezuelan subsidiary of Gulf Oil Corp),” Pardo said. “I had graduated in 1943, and worked in the San Tome stratigraphic laboratory.”

The highly influencial Hollis Hedberg (in whose honor AAPG Hedberg Conferences are named) was the chief geologist there – and was one of Pardo’s sponsors for Active membership and later a close friend and mentor.

Hedberg was responsible for Pardo going to Cuba.

“While Hedburg was Gulf’s chief geologist for foreign exploration in New York he came to my office with a stack of reports,” Pardo said, “and said “’Georges, try to make sense of this. It’s a mess.’

“A few days later I went to his office and suggested to forget about everything and start studying the island all over again,” he continued. “He said ‘Good idea!’ and a week later I was on my way to Cuba.”

The Lost Years
Georges Pardo
Georges Pardo

Pardo was in Cuba a couple of times prior to 1952, and then resided and worked there as chief geologist of Cuban Gulf Oil from 1952 to 1955.

“I never returned to the island after that,” he said. “I also kept contacts with Harry Wassall (founder and CEO of Petroconsultants) and established a good friendship with Manuel Iturralde-Vinent, from the Museum of Natural History in Havana.

“The work we did in Cuba (with P. Bronnimann, Wassall and Truitt) in the 1950s was truly pioneering, but for one reason or another was never published in its entirety,” he said. “Then Castro came, and communications were lost for many years.”

With his interest kindled, Pardo gave several oral presentations on Cuba at AAPG and Geological Society of America meetings in New York, New Orleans, Caracas and other venues. He also wrote the paper “Geology of Cuba” for the series “The Ocean Basins and Margins” (Vol. 3, 1975), edited by Nairn and Stehli.

Pardo also contributed to “The Geology and Tectonic Evolution of the Northern Caribbean Margin,” by Lewis and Draper, 1990 GSA, and DNAG “The Geology of North America, The Caribbean Region,” edited by Dengo and Case. He also wrote a report on Cuba for Wassall’s Petroconsultants.

“Having been involved in the geology of Cuba for quite a few years, I decided that it would be a shame not to try to put all this information – much of it never published – in one volume, and also incorporate the older information into new, very good data coming out of new generations of students of Cuban geology,” he said.

Big Potential – Or Big Talk?

Pardo explained that Cuba is part of an orogenic belt that forms the southern boundary of the North American continent, and though it is the southern boundary of the Gulf of Mexico it has never been much written about in the U.S. literature.

There has been a lot of buzz lately about Cuba’s petroleum potential. Brazil signed an exploration agreement in November 2008, and in March Russia expressed interest in Cuban blocks and formed an exploration unit with Venezuela’s PDVSA for possible exploration there.

What does Pardo think of the huge estimates of potential being tossed about?

“I do not believe any of the published estimates,” Pardo said.

“On land, although source rocks and potential reservoirs are common (Cuba produced 52,000 Bod in 2007), the structural picture is incredibly complicated.

“There are very few ‘conventional structures,’” he continued, “and those are faulted, fractured, thrusted to an unbelievable intensity. In most cases, the thrust plane is the only seal.

“Most of the zone where oil has been found consists of relatively thin-bedded carbonates crushed between a slab of oceanic crust overriding the Bahamas carbonates and the southern Gulf of Mexico,” he said.

“To make matters worse,” he continued, “the seismic response of Cretaceous and older rocks is very poor – including high velocity, poor reflection coefficients and high dips. Nearly nothing has been published about the deep offshore except articles of a promotional nature.

“The few seismic profiles I have seen do not show anything coherent below the Tertiary cover.”

Already a number of fairly deep wells have been drilled along the north and northwest coast, and some of the wells bottom in sediments younger than at the surface.

“There is no indication that the extent of thrusting is known,” Pardo said. “To the south of the island there is no reason to believe that anything but volcanics, metamorphics and igneous rocks are present under a thin Tertiary cover.”

Wanted: A Complete Picture

If big success is to be had in Cuba, Pardo advises a comprehensive exploration program – including the Bahamas.

“Deep transects to clarify once and for all the deep structure under the island, and how it fits with North America will be needed,” he said. “I am afraid that the “lease-by-lease” approach will not do it.”

With Gulf, Pardo also worked at the Gulf Research Laboratory, was regional geologist in the Latin American operations-domestic exploration and served as exploration vice president for Gulf Global Exploration. When Gulf and Chevron merged in 1984, Pardo retired as general manager of Gulf’s Central Exploration Group and Houston Technical Service Center.

But the geology of Cuba was still on his mind.

Studies 58 includes 88 printed pages and 360 total pages on CD-ROM (the 360 pages include the 88 printed pages plus additional data).