Geomechanics (from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''γεός'', i.e. prefix ''geo-'' meaning "

earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

"; and "

mechanics Mechanics () is the area of physics concerned with the relationships between force, matter, and motion among Physical object, physical objects. Forces applied to objects may result in Displacement (vector), displacements, which are changes of ...

") is the study of the mechanical state of the Earth's crust and the processes occurring in it under the influence of natural physical factors. It involves the study of the mechanics of soil and rock.

Background

The two main disciplines of geomechanics are

soil mechanics Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and ...

and

rock mechanics Rock mechanics is a theoretical and applied science of the mechanical behavior of rocks and rock masses. Compared to geology, it is the branch of mechanics concerned with the response of rock and rock masses to the force fields of their physical ...

. Former deals with the soil behaviour from a small scale to a

landslide Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...

scale. The latter deals with issues in geosciences related to rock mass characterization and rock mass mechanics, such as applied to petroleum, mining and civil engineering problems, such as

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petr ...

stability, tunnel design, rock breakage, slope stability, foundations, and rock drilling. Many aspects of geomechanics overlap with parts of

geotechnical engineering Geotechnical engineering, also known as geotechnics, is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics to solve its engineering problems. I ...

engineering geology Engineering geology is the application of geology to engineering study for the purpose of assuring that the geological factors regarding the location, design, construction, operation and maintenance of engineering works are recognized and accou ...

, and geological engineering. Modern developments relate to

seismology Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes (or generally, quakes) and the generation and propagation of elastic ...

continuum mechanics Continuum mechanics is a branch of mechanics that deals with the deformation of and transmission of forces through materials modeled as a ''continuous medium'' (also called a ''continuum'') rather than as discrete particles. Continuum mec ...

, discontinuum mechanics, transport phenomena,

numerical methods Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods t ...

etc.

Reservoir Geomechanics

In the petroleum industry geomechanics is used to: * predict pore pressure * establish the integrity of the cap rock * evaluate reservoir properties * determine in-situ rock stress * evaluate the wellbore stability * calculate the optimal trajectory of the borehole * predict and control sand occurrence in the well * analyze the validity of drilling on depression * characterize fractured reservoirs * increase the efficiency of the development of fractured reservoirs * evaluate hydraulic fractures stability * study the reactivation of natural fractures and structural faults * evaluate the effect of liquid and steam injection into the reservoir * analyze surface subsidence * determine the degree of the reservoir compaction * quantify production loss due to the reservoir rock deformation * evaluate shear deformation and casing collapse To put into practice the geomechanics capabilities mentioned above, it is necessary to create a Geomechanical Model of the Earth (GEM) which consists of six key components that can be both calculated and estimated using field data: * Vertical stress, δv (often called geostatic pressure or overburden stress) * Maximum horizontal stress, δHmax * Minimum horizontal stress, δHmin * Stress orientation * Pore pressure, Pp * Elastic properties and rock strength: Young's modulus, Poisson's ratio, friction angle, UCS (unconfined compressive strength) and TSTR (tensile strength) Geotechnical engineers rely on various techniques to obtain reliable data for geomechanical models. These techniques include coring and core testing, seismic data and log analysis, well testing methods such as transient pressure analysis and

hydraulic fracturing Fracking (also known as hydraulic fracturing, fracing, hydrofracturing, or hydrofracking) is a well stimulation technique involving the fracturing of Formation (geology), formations in bedrock by a pressurized liquid. The process involves the ...

stress testing, and geophysical methods such as acoustic emission.

References

Additional sources

* * Mechanics Earth sciences Geotechnical engineering {{Civil-engineering-stub

Background

Reservoir Geomechanics

See also

References

Additional sources