The first chain of exploration process is the areas geological knowledge and basic geological maps in different scales which Iran possesses over a hundred years of experience in the study of hydrocarbon exploration. Along with field study, exploration of hydrocarbon in various kinds of oil traps using satellite map studies and then surface operations such as stratigraphy, oil geochemistry and sedimentology are the activities that are implemented in surface geology. In addition to the study, interpretations and recognizing the potentiality of oil and gas hydrocarbon, these studies include exploration goals at the depth of production-development fields. Day after day, complex exploration goals become the candidate of the exploration of today and the future. We can refer to structural andstratigraphictraps, traps related to the faults and the traps inside or surrounding salt domes.Facies recognition and proper potential sediments and relating them to hydrocarbon systems have developed in recent decade.
After introducing the proper point for drilling the exploration well, there starts the activities of another group of Exploration Directorate. Plans for drilling, observation of the operation, suggestions for in-well testing, interpretation of the logs and choosing certain distances in the well are the responsibility of sub-surface geology, petrophysics and reservoir engineers and finally the reports of exploration from the well will be prepared by petroleum planning and engineering.
The main principle for the formation of an oil and gas hydrocarbon system is the source rock. Recognition of the potentiality, its maturity, and interpretation of basin patterns, immigration paths and its accumulation need precise geochemical studies for oil exploration. This is a basic study that is done along with geological studies in an area.
All the attempts of the experts in earth sciences are done to achieve a suitable image of the reality and geometry of the reservoir under the earth and this is a challenge that can be solved through being equipped with proper tools and knowledge that require the latest scientific, technical and managerial achievements in exploration. Geophysics science was established for this reason and has had a lot of advances so far. Methodologically, geophysics is divided into the two groups of seismic and non-seismic in Exploration Directorate. Processes of seismological activities such as 2D and 3D methods and non-seismic geophysics such as planning and supervision, processing and interpretation of data and information are planned, executed and led by geological and geophysical experts. Being efficient and economical in various processes of the execution of project are very important due to the high expenses of geophysical projects.
Through the interpretation of geophysical data by professional geophysical and geological experts a pattern and geometrical image of depth and the exploration goals for studies under the earth are presented which are effective in making exploration, development and productiondecisions. For the promotion of logging, interpretation and implementation of new geophysical methods, there have been continual training of the professional young experts to update them with the newest world progresses in the field. Geophysics and geology are organized structures of operation processes, observation of processing, interpretation of geophysical and geological data, research and the maintenance of underground data and information.
Exploration of mega fields such as Azadegan, South Pars, Asaloue, Yadavaran, Tabnak, Madar, Sepehr, Khyam, Changouleh, Kish, Khartang , … are among the achievements of Exploration Directorate in recent decades. It can besaid that Exploration Directorate holds the first rank in gas reservoirs and the fourth rank in oil in the world. It has explored 17572/730 million barrels of retrievable crude oil and 627106/87 million cubic meter of gas after Revelation and it can also be said that all the gas in gas pipeline networks have been explored after the Revolution of 1979.
Among the 1-7 exploration priorities which have high costs, Exploration Directorate has focused on the 1-3 priorities and at the same time continues its comprehensive and systematic studies in priorities 1-4 which include geological map preparation and geochemical and geophysical studies. Hence, comprehensive studies have been done in Moghan Field, Makran, Tybad and Tabas and 6 comptehensive studies have been done in sedimentary basins in the country and over 230 geological maps at the 1:50000 , 1: 100000 have been prepared. This maps can also be used for comprehensive support and study of other civil activities for other organizations.