Oil Fields of West Buchivacoa, Venezuela

Abstract

Before 1907 attention was directed to the oil possibilities of West Buchivacoa by a fairly big and active seepage of light oil at El Mene. The first known geological report on the El Mene area was made in 1912 when the region was uninhabited. Drilling commenced in 1920. By 1925 the peak of production was reached. Production still continues, a total of 29 million barrels of oil having been obtained. The presence of oil at El Mene is due to a late movement which rejuvenated anticlinal folding on a pre-existing eroded axis. An important contributing factor is that the overburden of early Miocene rocks has curbed the folding movement, thus preventing excessive shattering which would have resulted in the escape of most of the oil. Farther along the axis, crushing and shattering has taken place, and remnants of oil in fault traps are all that have been formed, for example, 3 million barrels at Media and 4 million barrels at Hombre Pintado. The process of erosion is impressively displayed in the semi-arid zone of the first foothills, where extremely heavy showers of short duration remove the generally soft sandy rocks with great rapidity. Drilling at El Mene was very easy and the average depth of wells was 1,000 feet. Producing-sand thicknesses are variable but average 25 feet. The oil is of mixed base, sulphur-free and of gravity 32°API (.865).