Oil Pool of Open Reservoir Type

It has been stated that no commercial accumulations of petroleum have been found in areas where the controlling structure is a simple terrace in the reservoir sand. That is, in all pools located on apparent terraces, trapping is caused by buried closure or by variations in the porosity of the reservoir rock.(FOOTNOTE 3) In most instances, this is undoubtedly true. However, pools are known in which open terraces are the only causative structures for retaining the oil in place. The Wheat pool is believed to be an example of this type. A description of the geology is followed by suggestions as to the possible origin and maintenance of such an accumulation.