Abstract
A mature area located in Western Venezuela is enclosed by three main fields, all of them in advanced state of depletion based on the way they have been exploited up to now since 1930. These heavy oil fields have a crude that ranges from 10-14 °API, a viscosity between 1000 and 25000 cp and cyclic steam is the way of stimulation as an standard process for all the new wells and the workovers. Cyclic Steam is becoming less efficient after three cycles application, the steam to oil ratio (<5), which is too low for these fields. Since before reaching this value it used to be around 30-40 for the first three cycles, which is considered a good value. Considering that the oil in place is more than 20 billions barrel of oil and only 23% has been recovered beside the latest static models show that several of the sand bodies has not been drained out as yet. A different strategy or a new plan for the redevelopment of the area is necessary in such a way that the exploitation of these fields could be extended for twenty or more years. This study shows that with good static and dinamic models a reassessment of the whole area can be done, by ways of dividing into regions the fields and applying different producing technologies, some of these technologies are thermal recovery methods as cyclic steam, steamflood, SAGD, electromagnetism and Combustion. All of this will increase the recovery factor up to 80%. The non drained sand bodies could be stimulated by applying cyclic steam in areas of the field with good thermal communication. These are candidates for steamflood and in the areas with clean sand bodies up to 40 ft. Thick, SAGD can be applied. Finally the very depleted reservoirs with low pressure and clean sands are the best for either dry o wet combustion.
