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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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.

References

1. Butler R.M., *Horizontal wells for the recovery of oil, gas and bitumen*,

Petroleum Society of the Canadian Institute of Mining,

Metallurgy and Petroleum, 1994, 228 p.

2. Suchkov B.M., *Gorizontal'nye skvazhiny *(Horizontal wells),

Moscow – Izhevsk, RKhD Publ., 2006, 422 p.

3. Economides, M.J., Naceu, K.B., Klem, R.C., *Matrix stimulation*

*method for horizontal wells*, JPT, July 1991, pp. 854-860.

4. Liu Hai, Coston C., Yassin M., Uddin Sh., Al-Dhafeeri F., *A novel*

stimulation technique for horizontal openhole wells in carbonate

*reservoirs—a case study in Kuwait*, SPE 105127, 2010.

5. Al-Dhufairi M., Al-Ghamdi S., Noya V., Al-Aradi Kh., Al-Sarakbi

S., Al-Dossary A., Krueger E., Moore B., *Merging tapered in*

Coiled Tubing (CT) and well tractor technologies to effectively stimulate extended

*reach open hole horizontal wells, *SPE 130642, 2011.

6. *Patent no. 2082880 RF, Method of acid treatment of oil formation*, Inventors:

Orlov G.A.; Muslimov R.Kh.; Yusupov I.G.; Musabirov M.Kh., 1997.

7. Kharisov R.Ya. , Bulgakova G.T. , Sharifullin A.R., Makatrov A.K., Telin A.G.,

Pestrikov A.V., *Geologiya, geofizika i razrabotka neftyanykh i gazovykh*

*mestorozhdeniy, *2010, no. 7, pp. 44–50.

8. Sorbie K.S., Scaled miscible floods in layered beadpacks investigating viscous

crossflow, SPE 20520, 1990.

9. Frick T.R., Economides M.J., *Horizontal well damage characterization and*

*removal*, SPE Production and Facilities, February 1993.

10. Bulgakova G.T., Kharisov R.Ya., Sharifullin A.R., Pestrikov A.V., *Nauchnotekhnicheskiy*

*vestnik OAO “Rosneft'”*, 2010, no. 2, pp. 16–20.

11. Bulgakova G.T., Kharisov R.Ya., Sharifullin A.R., Pestrikov A.V., *Territoriya*

*NEFTEGAZ*, 2010, no. 11, pp. 18–22.

12. Idel'chik I.E., *Spravochnik po gidravlicheskim soprotivleniyam *(Handbook

on hydraulic resistance), Moscow: Mashinostroenie Publ., 1992, 672 р.

13. Patankar S.V., *Numerical Heat Transfer and Fluid Flow, *Hemisphere Publ.

Co., 1980.

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.

**
**
* *
*
*
*
*
* *
* *
* *
* *

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.

References

1. Butler R.M., *Horizontal wells for the recovery of oil, gas and bitumen*,

Petroleum Society of the Canadian Institute of Mining,

Metallurgy and Petroleum, 1994, 228 p.

2. Suchkov B.M., *Gorizontal'nye skvazhiny *(Horizontal wells),

Moscow – Izhevsk, RKhD Publ., 2006, 422 p.

3. Economides, M.J., Naceu, K.B., Klem, R.C., *Matrix stimulation*

*method for horizontal wells*, JPT, July 1991, pp. 854-860.

4. Liu Hai, Coston C., Yassin M., Uddin Sh., Al-Dhafeeri F., *A novel*

stimulation technique for horizontal openhole wells in carbonate

*reservoirs—a case study in Kuwait*, SPE 105127, 2010.

5. Al-Dhufairi M., Al-Ghamdi S., Noya V., Al-Aradi Kh., Al-Sarakbi

S., Al-Dossary A., Krueger E., Moore B., *Merging tapered in*

Coiled Tubing (CT) and well tractor technologies to effectively stimulate extended

*reach open hole horizontal wells, *SPE 130642, 2011.

6. *Patent no. 2082880 RF, Method of acid treatment of oil formation*, Inventors:

Orlov G.A.; Muslimov R.Kh.; Yusupov I.G.; Musabirov M.Kh., 1997.

7. Kharisov R.Ya. , Bulgakova G.T. , Sharifullin A.R., Makatrov A.K., Telin A.G.,

Pestrikov A.V., *Geologiya, geofizika i razrabotka neftyanykh i gazovykh*

*mestorozhdeniy, *2010, no. 7, pp. 44–50.

8. Sorbie K.S., Scaled miscible floods in layered beadpacks investigating viscous

crossflow, SPE 20520, 1990.

9. Frick T.R., Economides M.J., *Horizontal well damage characterization and*

*removal*, SPE Production and Facilities, February 1993.

10. Bulgakova G.T., Kharisov R.Ya., Sharifullin A.R., Pestrikov A.V., *Nauchnotekhnicheskiy*

*vestnik OAO “Rosneft'”*, 2010, no. 2, pp. 16–20.

11. Bulgakova G.T., Kharisov R.Ya., Sharifullin A.R., Pestrikov A.V., *Territoriya*

*NEFTEGAZ*, 2010, no. 11, pp. 18–22.

12. Idel'chik I.E., *Spravochnik po gidravlicheskim soprotivleniyam *(Handbook

on hydraulic resistance), Moscow: Mashinostroenie Publ., 1992, 672 р.

13. Patankar S.V., *Numerical Heat Transfer and Fluid Flow, *Hemisphere Publ.

Co., 1980.