I took this photograph in the period of my internships with the datalog company during my internships, in the drilling of the exploratory well A-1R in Rubio, Táchira state, where I can be observed in the company of my internship partner Jonder Gerardo García.
Introduction
When the decision is made to drill an exploratory well, it is because there is no geological information of the deposit that we believe has oil and natural gas, for the workers involved in the drilling of these types of wells. it is an activity of operational challenges, since one of the most dangerous elements that is unknown is that of pore or reservoir pressure, although after the well is completed, the other perforations of the same deposit will be more convincing and less blind, since the geological data and records of the exploratory well drilling will be recorded for future drilling in the same field.In essence, I could say that the drilling of exploratory wells is an important part of the global oil industry, since through the drilling of these wells we can record a series of geological, operational, drilling fluid data and we can even estimate everything related to the logistics to be implemented for the drilling of future wells.
The investment for the drilling of a well in development is very high costs, now well drilling an exploratory well does not escape this reality, even the expense generated by the drilling of an exploratory well exceeds that of the wells in development, all this investment is recovered after all the wells that are drilled within the deposit that has been studied by exploratory drilling are produced, apart from this all the information that is obtained and that is saved has an annex value that balances the expense generated during the drilling of the exploratory well.
Objectives within exploratory drilling
The main objective of drilling an exploratory well is to know if an area containing oil and natural gas (reservoir) contains or does not contain the hydrocarbon, for this it is necessary to drill the well to the depth where it is believed to be the reservoir that contains the hydrocarbon. You can not start the drilling of an exploratory well without first having a detailed plan of how the operational activities will be carried out in the drilling and construction of the well, for this it is necessary that we elaborate a drilling program according to the data obtained in the seismic, by means of these seismic data we can know to what depth we can reach the perforation, through the seismic we can obtain an estimated record of reservoir pressures, and in this way we can adjust the density of the mud and the different circulation and hydrostatic pressures of the mud, and in this way prevent future attacks from the well and the undesirable blowout.
Conclusion and considerations in exploratory well drilling
Many of us could think that the discovery of oil and natural gas could be covered with the data obtained in the seismic, a situation that is wrong, since with the data obtained in the seismic we can only have a slight orientation to enter the drilling of a well that is in an unknown oil field, and that the only thing we know are certain aspects such as the depth of the reservoir where the hydrocarbon is contentively, and an estimate of pressures under which we can not trust, since many of these pressure registers Seismic estimates are provided, and true pressures are not found during drilling.
All this situation leads me to recommend that when drilling an exploratory well take care of safety aspects, for this we must have a preventor or set of valves prevents bursting that is at the height of the estimated seismic pressures, and This way we can explore without having risks of accidents and disasters caused by a back pressure produced by a bad design in the drilling of the exploratory well. Once these considerations are taken into account, it is only necessary to keep information of all kinds, geological, operational, economic and logistic, since these data will be very valuable when drilling other wells that belong to the same deposit.
