Abstract
A mature area in an advanced state of depletion can be reassessed as to either maintain the current production or to increase it at least in a minimum amount. Most important of all is to be able to increase the recovery factor. The variables that are related to the oil production are correlated to the sedimentology-stratigrahy model as to give us the most appropriate arrangements of wells and to relocate locations which could have given less production than expected. The facies for each of the environment of deposition identified in every producing reservoir of the formation are described based on which we locate the present wells and compare to the future locations. This is a heavy oil field producing since 1930. The crude ranges between 10–14 °API, the viscosity is in the range of 1000 to 25000 cp. The method of production is cyclic steam stimulation (CSS) which after three cycles becomes less efficient. The steam to oil ratio (SOR) is less than five from initial values of 30–40. Having a huge reserve in the area, however the recovery factor is only 23%. Since several of the sandbodies have not been yet drained out, this gives a new challenge by which a new approach will be used as to produce these bodies. Using sedimentology concepts we can determine the paleodeposition based on the existing facies in this way we locate new locations to optimize well production. Once we locate the new wells, we will be able to screen out the most appropriate way of production by applying thermal methods. Cyclic Steam Stimulation (CSS), steamflood, SAGD, Electromagnetism or Combustion, all together will increase the recovery factor an accumulated 80% of the reserves. The non-drained sandbodies could be stimulated with Cyclic Steam Stimulation (CSS) followed by steamflood in areas of the model with good thermal communication. Finally the very depleted reservoirs with low pressure and clean sands are the best for dry or wet combustion.
