Life of the oil field


Today, I am going to describe a life of the oil field. Probably the topic is obvious and well known but the basic knowledge is worth to be repeated. Oil field is a region with a large number of boreholes extracting petroleum. Oil fields typically occupy large areas up to several hundred kilometers in width, so the total utilization of the deposit is possible only thanks to location many boreholes around the area.

Before starting exploitation of the deposit, firstly of course we have to discover it, and make inventory of resources. Promising geological formations are examined by analyzing the propagation of the artificially generated seismic waves in the earth’s crust. Test drilling are performed, and then we can start extraction. At the beginning crude oil is readily available and it is easy to increase production. Later, it is more complicated: we have to pump it, squeeze out of the ground by introducing water and gas into the reservoir – production will be stabilized and then will be decreased.

Advanced mining and drilling techniques allow very efficient exploitation of the deposit of oil. Several decades ago it was normal to extract approximately 20% of the deposit. But today we can exploit even more than 50%. The specific value depends on the type of oil layer, the deposit and other factors like porosity, permeability, etc. Regardless of the type and the efficiency of the mining methods, there remains less and less crude oil in the deposit. In the extracted crude oil is also more water. When the amount of water becomes too large (eg. 99%), we should abandon wellbore. Gradually we will turn off the exploitation of the oil wells. The typical lifetime of an oil field is a several / a few dozen years and depends largely on intensity of exploitation. Deposits which are intensively exploited (particularly with the use of horizontal wells enabling rapid pumping of oil) reach “end” much faster. Also decrease of production of such a deposit is characterized by a rate of over a dozen percent per year, in contrast to several percent per annum for deposits exploited using “classical” methods.

The world is full of old, abandoned oil sites. Once there were lively places, giving employment to thousands of people, providing energy throughout the countries. Today – there are only abandoned, decaying remains of old wells, pumps and destroyed infrastructure.

And what’s more? Any questions? I urge you to search on!



About author

Radosław Budzowski

Logistics Manager in YoungPetro, third year student of Oil and Gas Engineering at the Faculty of Drilling, Oil and Gas at AGH. Interested in reservoir engineering and gas industry. Privately badminton and travels enthusiast.

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