Helios Energy Limited announced its plan to spud and complete a 4th well in its Presidio Oil Project located in Presidio County, Texas, USA by 31 December 2021. During 2021, Helios integrated all its geological and geophysical data with the aim of high grading multiple well locations that target the Ojinaga Formation (primary target) but which also include the Eagle Ford Formation (secondary target) as well as the older Cretaceous units being the Buda, Georgetown and Edwards limestone formations. Helios has acquired gravity and magnetic data over the entire Presidio Oil Project. Interpretation of that data has been compared with the entire seismic programme, along with data from the 3 new wells and the existing old well data. The data sets, when compared, evidence a high degree of matching or fit. The presence therefore of the Ojinaga Formation across the entire Ojinaga Formation play area can be easily mapped. This gravity and magnetic data analysis have played an important part in increasing the Presidio Oil Project play area to 300,000 acres.