Analysis of conductivity changes of acid-etched fractures depending on influential factors has been conducted. The following conclusions have been made. Efficiency of acid fracturing increases with decrease of producing reservoir depth. Appropriate candidate formations for acid fracturing are those characterized by high Brinnel hardness and those having low fracturing pressures. Reservoir pressure drop is not allowed while operating the wells with acid-etched fractures. Instead, increase of reservoir pressure is advisable. If the stress resulting in loss of conductivity in acid-etched fractures lies within the actual range of compressional stresses (from 0 to 30 MPa in Tatarstan conditions), so the optimum value of reservoir pressure drawdown will exist ensuring maximum production rate and well productivity. Combination of horizontal wells and multiple transverse acid-etched fractures is a viable solution for reduction of compressional stress.
References
1. Lysenko V.D., Neftepromyslovoe delo, 2006, no. 12, pp. 4–7.
2. Medvedskiy R.I. et al., Neftepromyslovoe delo, 2007, no. 11, pp. 23–27.
3. Ibatullin R.R., Nasybullin A.V., Salimov O.V., Collected papers “Teoriya i praktika sovremennykh metodov intensifikatsii dobychi nefti i uvelicheniya nefteotdachi plastov” (Theory and practice of modern methods of oil production
intensification and EOR), Proceedings of International scientific-practical
conference, Republic of Belarus, Retchitsa, 23-25 May 2012, Gomel': Publ. of
Polespechat', 2012, pp. 471–478.
4. Ibatullin R.R., Salimov V.G., Nasybullin A.V., Salimov O.V., Neftyanoe
khozyaystvo – Oil Industry, 2012, no. 9, pp. 73–77.
5. Mordvinov V.A., Poplygin V.V., Erofeev A.A., Neftyanoe khozyaystvo – Oil Industry, 2012, no. 10, pp. 102–105.
6. Nierode D.E., Kruk K.F., An evaluation of acid fluid loss additives, retarded
acids, and acidized fracture conductivity, Paper SPE 4549, 1973.
7. Gong M. et al., A new model of acid fracture conductivity based on deformation
of surface asperities, Paper SPE 39431, 1998.
8. Abass H.H., et al., Acid fracturing or proppant fracturing in carbonate formation?
A rock mechanic’s view, Paper SPE 102590, 2006.
9. Diyashev R.N., Kosterin A.V., Skvortsov E.V., Diyashev I.R., Neftyanoe
khozyaystvo – Oil Industry, 1993, no. 11, pp. 23–26.
