Optimizing the acidizing operations of horizontal wells in carbonate reservoirs

Authors: G.T. Bulgakova (Ufa State Aviation University, RF, Ufa), R.Ya. Kharisov, A.R. Sharifullin (RN-UfaNIPIneft, RF, Ufa), A.V. Pestrikov (Rosneft Oil Company OJSC, RF, Moscow)

Key words: horizontal well, carbonate reservoirs, interval acid treatment, mathematical model
The objective of the paper is to develop a mathematical model of acid treatment of horizontal wells in carbonate reservoirs to control the distribution flows of acid solutions and chemical diverters. The model presented in the paper has been constructed for an openhole well. Treatment is performed by pumping treatment fluids under pressure through coiled tubing (CT). The model assumes a radially symmetric initial profile of permeability. The mathematical model predicts the location of the injected fluids by tracking the advance of the fronts. Mathematical simulation enables one to solve the problem of determining the optimal positioning of the CT end to uniformly cover the whole treatment interval. In the course of a computational experiment the parameters are studied which influence the improvement of permeability and porosity of the borehole environment. Also determined are their optimal values to ensure maximal efficiency of acid treatments of horizontal wells in carbonate reservoirs.

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