Cusiana Trend Exploration, Llanos Foothills Thrustbelt, Colombia: The Opening of a New Hydrocarbon Province

John O'Leary, Tony Hayward, Fergus Addison, and German Espinosa

The Llanos Foothills petroleum trend of the Eastern Cordillera in Colombia containing the giant Cusiana Field has proven to be one of the most exciting hydrocarbon provinces discovered in recent years. The Llanos Foothills trend is a fold and thrust belt with cumulative discovered reserves to date of nearly 6 billion barrels of oil equivalent. This paper summarises the critical exploration techniques used in unlocking the potential of this major petroleum system.

The first phase of exploration in the Llanos Foothills lasted from the early 1960s to the mid '70's. Several large structures defined by surface geology and seismic data were drilled. Although no major discoveries were made, evidence of a petroleum play was found. The seismic imaging and drilling technology combined with the geological understanding which was then available did not allow the full potential of the trend to be realised.

In the late 1980s better data and a revised geological perception of the trend led BP, Triton and Total into active exploration, which resulted in the discovery of the Cusiana Field. The subsequent discovery of the Cupiagua, Volcanera, Florena and Pauto Sur Fields confirmed the trend as a major hydrocarbon province. The exploration programme has used a series of geological and geophysical practices and techniques which have allowed the successful exploitation of the trend. The critical success factor has been the correct application of technology in seismic acquisition and processing and drilling techniques.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California