Oil Well Stimulation at Oil Fields of Groznensky Oil-Bearing District

Abstract

Among the objectives of the oil industry of the Chechen Republic is stable covering of requirements of the republic for hydrocarbons; attaining this objective significantly depends on acceleration of scientific and technical progress within the industry. It assumes increase in oil and associated gas production not only by means of accelerated development of new deposits, but also by wide application of progressive formation stimulation that ensures increasing output of wells in already developed deposits. One of the principal methods used to increase oil production efficiency is physical and chemical interaction with the bottom-hole zone with the aim of increasing its permeability and providing connectivity between the bottomhole and the formation; among the solutions applied, the most common are mud acid and hydrophobic acidic emulsions on its base. This work gives comparative analysis of various chemical methods used to stimulate oil inflow to bottomhole. It has been established that when acid is injected, it is mostly accumulated in highly permeable intervals, while those of low permeability comprising the bulk of the formation are barely exposed to the chemical action. Due to that, treatment with this technology leads to increased permeability of individual sublayers that had high permeability to begin with. Another cause of low efficiency of acid treatment is that increase in formation temperature leads to an abrupt shortening of the hydrochloric acid neutralization period and increased corrosive activity of the acid. Shortened neutralization period significantly contributes to worsening reservoir properties for deeper productive formation, in particular, fracture opening reduction. As a result, only the areas of the formation in the immediate vicinity of the well bore are subjected to the treatment. The authors emphasize that additional research is needed to find more efficient processes for developing Mesozoic deposits.