Prediction of fractured zones in the rocks based on calculation of deformations

UDK: УДК 551.252:622.276.1/.4
DOI: DOI: 10.24887/0028-2448-2021-11-98-102
Key words: rock formation, oil and gas, fractures, structure, tectonophysics, strain field
Authors: T.R. Yalaev1, R.D. Kanevskaya1,2, Yu.L. Rebetsky3, V.A. Kiryachek1, V.V. Volianskaia4 1IGiRGI JSC, RF, Moscow 2Gubkin University, RF, Moscow 3Sсhmidt Institute of Physics of the Earth of the RAS, RF, Moscow 4Rosneft Oil Company, RF, Moscow

The problem of localization of fractured zones is one of the most important for the development of fractured reservoirs. Its relevance is determined by the fact that in most cases these zones are located unevenly in area, and at the same time it is hard to identify them by direct methods. The paper proposes a method for localizing zones with a high content of fractures associated with tectonic mechanisms of how it is forming. It is based on the assumption that the strain field determines the zones of fracture propagation using a design characteristic called the fracture intensity, which is expressed through the invariants of volumetric strain and the intensity of shear strain. The method allows to build a map of fracture intensity, as well as to determine the preferred direction of fractures. The method has been successfully tested at one of the oilfields in Russia. Two approaches to assessing the strain field are considered. Taking into account the applied relationships, they are called "geomechanical" and "tectonophysical". So, for the tectonophysical approach, structural data are required (the position of horizons, faults, which can be distinguished from seismic data, as well as, if available, information on the kinematics of these faults). The geomechanical approach additionally requires formation mechanical properties (Young's modulus and Poisson's ratio), Biot's ratio, rock density, and pore pressure.

References

1. Biot M.A., General theory of three dimensional consolidation, Journal of Applied Physics, 1941, V. 12, no. 2, pp. 155–164.

2. Gallagher R.H., Finite element analysis: Fundamentals, Pearson College Div., 1975, 420 p.

3. Zienkiewicz O., The finite element method in engineering science, London; New York: McGraw-Hill, 1971, 521 p.

4. Fadeev A.B., Metod konechnykh elementov v geomekhanike (Finite element method in geomechanics), Moscow: Nedra Publ., 1987, 221 p.

5. Skvortsov A.V., Triangulyatsiya Delone i ee primenenie (Delaunay triangulation and its application), Tomsk: Publ. of Tomsk University, 2002, 128 p.

6. Kudinov V.A., Tekhnicheskaya termodinamika i teploperedacha (Technical thermodynamics and heat transfer), Moscow: Yurayt Publ., 2019, 454 p.

7. Papadopoulos P., Introduction to the finite element method, Department of Mechanical Engineering, University of California, Berkeley, 2010, 204 p.

8. Antonov A.S., Parallel'noe programmirovanie s ispol'zovaniem tekhnologii OpenMP (Parallel programming using OpenMP technology), Moscow: Publ. of MSU,  2009, 77 p.

9. Balandin M.Yu., Shurina E.P., Metody resheniya SLAU bol'shoy razmernosti (Methods for solving large-dimensional simultaneous linear algebraic equations), Novosibirsk: Publ. of NSTU, 2000, 70 p.

The problem of localization of fractured zones is one of the most important for the development of fractured reservoirs. Its relevance is determined by the fact that in most cases these zones are located unevenly in area, and at the same time it is hard to identify them by direct methods. The paper proposes a method for localizing zones with a high content of fractures associated with tectonic mechanisms of how it is forming. It is based on the assumption that the strain field determines the zones of fracture propagation using a design characteristic called the fracture intensity, which is expressed through the invariants of volumetric strain and the intensity of shear strain. The method allows to build a map of fracture intensity, as well as to determine the preferred direction of fractures. The method has been successfully tested at one of the oilfields in Russia. Two approaches to assessing the strain field are considered. Taking into account the applied relationships, they are called "geomechanical" and "tectonophysical". So, for the tectonophysical approach, structural data are required (the position of horizons, faults, which can be distinguished from seismic data, as well as, if available, information on the kinematics of these faults). The geomechanical approach additionally requires formation mechanical properties (Young's modulus and Poisson's ratio), Biot's ratio, rock density, and pore pressure.

References

1. Biot M.A., General theory of three dimensional consolidation, Journal of Applied Physics, 1941, V. 12, no. 2, pp. 155–164.

2. Gallagher R.H., Finite element analysis: Fundamentals, Pearson College Div., 1975, 420 p.

3. Zienkiewicz O., The finite element method in engineering science, London; New York: McGraw-Hill, 1971, 521 p.

4. Fadeev A.B., Metod konechnykh elementov v geomekhanike (Finite element method in geomechanics), Moscow: Nedra Publ., 1987, 221 p.

5. Skvortsov A.V., Triangulyatsiya Delone i ee primenenie (Delaunay triangulation and its application), Tomsk: Publ. of Tomsk University, 2002, 128 p.

6. Kudinov V.A., Tekhnicheskaya termodinamika i teploperedacha (Technical thermodynamics and heat transfer), Moscow: Yurayt Publ., 2019, 454 p.

7. Papadopoulos P., Introduction to the finite element method, Department of Mechanical Engineering, University of California, Berkeley, 2010, 204 p.

8. Antonov A.S., Parallel'noe programmirovanie s ispol'zovaniem tekhnologii OpenMP (Parallel programming using OpenMP technology), Moscow: Publ. of MSU,  2009, 77 p.

9. Balandin M.Yu., Shurina E.P., Metody resheniya SLAU bol'shoy razmernosti (Methods for solving large-dimensional simultaneous linear algebraic equations), Novosibirsk: Publ. of NSTU, 2000, 70 p.



Attention!
To buy the complete text of article (a format - PDF) or to read the material which is in open access only the authorized visitors of the website can. .

Mobile applications

Read our magazine on mobile devices

Загрузить в Google play

Press Releases

18.05.2022
11.05.2022
28.04.2022