Wells – Processes – Vibrating the earth or material in or being placed in the...
Reexamination Certificate
2002-05-09
2004-11-09
Bagnell, David (Department: 3672)
Wells
Processes
Vibrating the earth or material in or being placed in the...
C166S177100, C166S050000, C166S308400
Reexamination Certificate
active
06814141
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to the field of oil production. More specifically, this invention relates to a method for improving recovery of oil, preferably heavy oil, by accelerating gravity drainage using vibrational energy generated from a well fracture.
BACKGROUND OF THE INVENTION
Steam-Assisted Gravity Drainage (SAGD) is one of the thermal methods of recovering heavy oil or bitumen with steam, where the oil contacted by steam drains down to a horizontal producing well by gravity. In the SAGD process of recovering bitumen, two horizontal wells are drilled in parallel close to each other, near the bottom of the bitumen pay zone, preferably one above the other. (Butler, R. M., Thermal Recovery of Oil and Bitumen, GravDrain Inc., Calgary, Canada (1997)). As shown in
FIG. 1
, steam is injected through the upper horizontal well
6
, to heat the bitumen, lowering its viscosity, and create a steam chamber
1
. As the steam chamber
1
grows, the lower viscosity oil
3
generated at its ceiling
5
and side walls
7
drains downward by gravity
9
, and is produced through the lower horizontal well
8
. Since the steam injector and the oil producer are very close to each other, any forced injection or production of fluids to speed up oil production will cause a rapid coning, or production of steam instead. Therefore, oil production has to be left to gravity as the sole driving force. While the oil recovery efficiency for SAGD is known to be fairly good, its major drawback is the slowness of oil production, because it relies solely on gravity to produce oil.
In the vapor extraction process (VAPEX), a solvent is used instead of steam to reduce the bitumen viscosity, but the oil production relies on gravity force alone and is slow. (Butler, R. M., and Mokrys, I. J., “A new process (VAPEX) for recovering heavy oils using hot water and hydrocarbon vapor”, J. Canadian Petrol. Tech., 30 (1), 97-106 (1991)). A newer related process, steam and gas push (SAGP), uses steam plus a noncondensible gas and again relies on gravity drainage. (Butler, R. M., “The Steam and Gas Push (SAGP),” Paper 97-137 presented at the 48th Annual Technical Meeting of the Petroleum Society of CIM, Calgary, Jun. 8-11, 1997).
Seismic vibration in the range of 5-120 Hz is known to sometimes improve oil recovery from mature oil reservoirs. Laboratory coreflood and imbibition test results have shown oil recovery improvement due to vibration. Typically, a large mechanical vibrator pounds the ground surface to transmit seismic energy to the reservoir zone. However, due to the typically long distance between the surface and the pay zone, only a very small fraction of the vibrational energy reaches the pay zone. Furthermore, a large fraction of the vibration generated is wasted as a surface (Rayleigh) wave, which may also have environmentally detrimental effects.
To transmit vibrational energy more effectively, a vibration source is sometimes lowered downhole to the pay zone to generate vibration at the wellbore. Even then, only a small fraction of reservoir volume receives a significant amount of vibrational energy. This is because vibration generated from the downhole vibrator, which is essentially a point source, propagates spherically in all directions and diminishes very quickly due to spherical divergence.
In U.S. Pat. No. 2,670,801 (Sherborne) sonic waves are generated in a well to vibrate an oil-bearing formation to increase recovery, and in U.S. Pat. No. 3,002,454 (Chesnut) explosives are detonated in a horizontal well to increase vertical permeability by generating fractures. U.S. Pat. No. 5,297,631 (Gipson) discloses a method for oil formation stimulation by sudden release of high pressure gas from a gun in a well. Further, U.S. Pat. No. 5,396,955 (Howlett) discloses a method wherein permeability of a reservoir is enhanced by acoustic waves targeted at the reservoir. Accordingly, there is a need for a low-cost method of accelerating oil production in gravity drainage processes and thereby reducing the steam or solvent requirement, as well as the project duration, for better process economics.
SUMMARY OF THE INVENTION
This invention provides a method of improving oil recovery comprising the steps of (a) creating at least one fracture in the vicinity of at least one well in a hydrocarbon pay zone; (b) installing a vibration source device in at least one well; (c) generating a fluid oscillation in the fracture using the vibration source device whereby the fluid oscillation in the fracture generates vibrational energy that increases gravity drainage in the hydrocarbon pay zone; and (d) removing oil from the hydrocarbon pay zone. Preferably, this method is used with steam-assisted gravity drainage or vapor extraction gravity drainage processes, but may be applied to single-well processes, such as huff-n-puff or cyclic steam stimulation processes.
REFERENCES:
patent: 2670801 (1954-03-01), Sherborne
patent: 3002454 (1961-10-01), Chesnut
patent: 3220476 (1965-11-01), Brandon
patent: 3692110 (1972-09-01), Grady
patent: 3754598 (1973-08-01), Holloway, Jr.
patent: 3990512 (1976-11-01), Kuris
patent: 4109721 (1978-08-01), Slusser
patent: 4280558 (1981-07-01), Bodine
patent: 4305463 (1981-12-01), Zakiewicz
patent: 4345650 (1982-08-01), Wesley
patent: 4432078 (1984-02-01), Silverman
patent: 4705108 (1987-11-01), Little et al.
patent: 4783769 (1988-11-01), Holzhausen
patent: 4836284 (1989-06-01), Tinker
patent: 5147535 (1992-09-01), Bernhardt
patent: 5170378 (1992-12-01), Mellor et al.
patent: 5184678 (1993-02-01), Pechkov et al.
patent: 5282508 (1994-02-01), Ellingsen et al.
patent: 5297631 (1994-03-01), Gipson
patent: 5396955 (1995-03-01), Howlett
patent: 5460223 (1995-10-01), Economides
patent: 5492175 (1996-02-01), El-Rabaa et al.
patent: 5641020 (1997-06-01), Cherry et al.
patent: 5855243 (1999-01-01), Bragg
patent: 5984578 (1999-11-01), Hanesian et al.
patent: 6095244 (2000-08-01), Graham et al.
patent: 6227293 (2001-05-01), Huffman et al.
patent: 6241019 (2001-06-01), Davidson et al.
patent: 6328102 (2001-12-01), Dean
patent: 6405796 (2002-06-01), Meyer et al.
patent: 6405797 (2002-06-01), Davidson et al.
patent: 6431278 (2002-08-01), Guinot et al.
patent: 6460618 (2002-10-01), Braithwaite et al.
patent: 6467542 (2002-10-01), Kostrov et al.
patent: 6499536 (2002-12-01), Ellingsen
Anonymous, “Seismic Source Technologies Developed for Deep Ocean Exploration”, ON&T, pp 22, May/Jun. 2001.
Butler, R.M. and Stephens, D.J., “The Gravity Drainage of Steam-Heated oil to Parallel Horizaontal Wells”, J. Canadian Petrol. Tech., 90-96, Apr.-Jun. 1981.
Butler, R.M., “Application of SAGD, Related Processes Growing in Canada”, Oil and Gas Journal, pp 74-78, May 14, 2001.
Butler, R.M., “Steam and Gas Push (SAGP)”, The Petroleum Society, Paper No. 97-137, pp 1-15, Jun. 8-11, 1997.
Butler, R.M., and Mokrys, I.J., “A New Process (VAPEX) for Recovering Heavy Oil Using Hot Water and Hydrocarbon Vapor”, J. Canadian Petrol. Tech, 30 (1), 97-106, (1991).
Butler, R.M., Thermal Recovery of Oil and Bitumen, GravDrain, Inc., Calgary, Canada (1997).
Holzhausen, G.R. and Gooch, R.P., “Impedance of Hydraulic Fractures: Its Measurement and Use for Estimating Fracture Closure Pressure and Dimensions”, SPE/DOE 13892 for SPE/DOE Low Permeability Gas Reservoirs Symposium, Denver CO., May 19-22, (1985).
Morse, P.M., Vibration and Sound, McGraw-Hill, New York (1948).
Shaaban Ashour, A.I., “A Study of the Fracture Impedance Method”, Ph.D. Thesis, University of Texas at Austin, May (1994).
Sneddon, I.N., Chapters 9 and 10 in “Fourier Transforms”, McGraw-Hill, (1951).
Tang, G.Q. and Morrow, N.R., “Influence of Brine Composition and Fines Migration on Curde Oil/Brine/Rock Interactions and Oil Recovery”, Journal of Petroleum Science and Engineering, vol. 24, pp 99-111 (1999).
White, J.E. Underground Sound—Application of Seismic Waves, Elsevier, Amsterdam (1983).
Bailey Jeffrey R.
Huh Chun
Shyeh Jung-gi Jane
Wylie, Jr. Philip Lee
Bomar T. Shane
ExxonMobil Upstream Research Company
Katz Gary P.
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