APPLICATION OF HYDRAULIC FRACTURING FOR INTENSIFYING OIL FLOW IN WELLS

Abstract

Today, most of the oil and gas reserves are difficult to recover, due to the fact that they are located in deposits of low-permeability and low-drained reservoirs. One of the enhanced recovery method for making oil extrac- tion from such deposits profitable, is hydraulic fracturing (HF). The method was discovered in the middle of the last century, but its rel- evance nowadays only increases. In the United States of America, the use of hydraulic fracturing is associated with the start of exploitation of shale deposits, and in Russia with an increase in the proportion of hard-to- recover oil. The technology of hydraulic fracturing consists in injecting a fracturing fluid into the production well under pressure exceeding the fracturing pressure. As a result, cracks are formed in the bottomhole zone, which are additional channels for filtering hydrocarbons and increase the overall permeability of the formation. In order to avoid the closure of cracks under the action of rock pressure, a proppant is added to the fracturing fluid - a granular material fixing the cracks. Various chemical reagents can also be added to increase the efficiency of the operation. The article presents tables with indication of various fracturing fluids and chemical reagents used during hydraulic fracturing, their compositions and areas of application. The differences between high- and low-permeable reservoirs in determining the flow rate and cumulative production are considered. An important criterion for the success of hydraulic fracturing is the selec- tion of a well. The best layers for this operation contain significant geo- logical volumes of oil and gas, but require an increase in the well produc- tivity coefficient.