DOI: 10.5593/sgem2017/12/S02.093


K. Benyounes, R. Saifi, M. Kerrouche, A. Mellak
Sunday 10 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 727-734 pp, DOI: 10.5593/sgem2017/12/S02.093


Many oil and gas low permeable reservoirs have been stimulated to enhance productivity. Acid fracturing is one of the commonly used well stimulation treatment in carbonate formations, such as limestone, dolomite, and chalk. Carbonate reservoirs are good candidates for acid fracturing since strong acids such as hydrochloric acid react easily with carbonate. The acid reacts within the fracture to create a differentially etched surface that will maintain a conductive pathway. Habitually, a pad fluid is injected ahead of the acid to initiate the fracture, and then an ordinary acid or fluid containing acid is injected. During the injection of pad, several models of fracture geometry have been used, which define the development of fracture geometry with time and treatment pressure. The dimension of a fracture affects the hydrocarbon production from the reservoir. Among the models used in the classic hydraulic fracturing are 2D models, where the KGD and the PKN models are most popular. In this wok, we have used the KGD model to simulate the geometry of fracture. We have showed that the half-length and width of fracture are affected by the injected time of PAD and flow index of fluid frac. An important half-length has been found for a low flow index with a maximal injection time. The increase in flow index leads to the growth of width. The half-length of the fracture increases gradually as the increase of the pumping rate of the fluid. The initial rate of fractured wells increases with the injection time by fixing the injection rate and for the same injection time, the production presents an optimum point. It is noted that the penetration of the acid increases with increase in flow index. The effect acid contact time on the initial oil flow rate and productivity index ratio were also investigated successfully.

Keywords: carbonate, oil, acid fracturing, stimulation, productivity index