Composition based on surfactants for thickening acid fracturing fluids

UDK: 622.276.63

DOI: 10.24887/0028-2448-2023-8-94-98

Key words: acid fracturing, thickened acid composition, surfactant, carbonate reservoir

Authors: M.A. Silin, L.A. Magadova, P.K. Krisanova, А.А. Filatov1, Yu.V. Sotnikova (Gubkin University, RF, Moscow)

Acid fracturing treatment is the key technique for stimulation production in carbonate reservoirs In this technique acid is injected to erode the fracture walls. Conductive channels which remain after fracture closure are created
because acid tends to etch the fracture faces in non-uniform patterns. The use of surfactants for thickening acid fracturing compositions has shown high efficiency due to their perspective and a number of advantages compared
to other fluids. This article presents the research on the development of a hydrochloric acid
thickening reagent for the preparation of acid fracturing fluid. The paper shows the results of experimental studies of the effect of the developed surfactants-based additive on rheological properties of 12 % hydrochloric acid,
interfacial tension at the boundary with hydrocarbons and solubility of carbonate. The addition of the mixture of surfactants leads to a significant increase in the viscosity properties of the acid systems, which provides a decrease in the rate of acid leakoff during acid fracturing. Also, this acid thickener contributes to reduction of interfacial tension at the boundary between theacid composition and hydrocarbons, which positively affects the efficiency of the process of acid fracturing. The application of the developed acid thickener leads to a decrease of carbonate solubility, which ensures the creation of the required non-uniform patterns of the carbonate fracture as well as an increase of acid penetration length during the acid fracturing process. After prolonged interaction of the acid composition based on the developed thickening agent with carbonate rock there is a decrease in the viscosity properties of the composition which facilitates further development process.