In-Situ Stress State Eastern Cordillera (Colombia) M.E. Torres; M.E. Torres Colombia National University -Schlumberger DCS Bogota Search for other works by this author on: This Site Google Scholar A.J. Gonzalez; A.J. Gonzalez Colombia National University Search for other works by this author on: This Site Google Scholar N.C. Last N.C. Last BP Exploration Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Latin American and Caribbean Petroleum Engineering Conference, Port-of-Spain, Trinidad and Tobago, April 2003. Paper Number: SPE-81074-MS https://doi.org/10.2118/81074-MS Published: April 27 2003 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Torres, M.E., Gonzalez, A.J., and N.C. Last. "In-Situ Stress State Eastern Cordillera (Colombia)." Paper presented at the SPE Latin American and Caribbean Petroleum Engineering Conference, Port-of-Spain, Trinidad and Tobago, April 2003. doi: https://doi.org/10.2118/81074-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Latin America and Caribbean Petroleum Engineering Conference Search Advanced Search AbstractKnowledge of the regional state of in situ stress direction and magnitude is required to delineate stress provinces, to analyze intra plate earthquakes, to optimize petroleum recovery and for the development of civil projects in rock masses. This paper on rock mechanics and reservoir geomechanics studies the stress state including the pore pressure that operates in the rock mass and the mechanical behavior of the rock, to create an integrated model to study the in situ state of stress in the Eastern Cordillera, Colombia. Several measurement techniques were used, which include strain-relief overcoring, hydraulic fracturing techniques, shear fractures in the walls of the boreholes knows as breakouts, leak off test and induced drilling tensile fracture in the walls of the boreholes. Rock mechanics properties are required for the application of these methods and laboratory tests were carried out to find elastic constants. The orientation of the maximum horizontal principal stress sHmax is parallel to that of tensile failures (tensile wall fractures) and perpendicular to that of compressive failures (breakouts). The magnitude of the minimum principal horizontal stress shmin is determined from leak off tests (LOT) and hydraulic fracturing, while the magnitude of the vertical stress sV is simply calculated based on the density data collected in several representative wells in the Cusiana field. From recent tectonics results are clear that the region in the Eastern Cordillera is characterized by an active strike-slip / thrust faulting regimen. The actual regional state of stress found means that the minimum principal stress shmin (0.65 psi/ft to 0.77 psi/ft) oriented in a NE-SW direction, is less than the vertical stress (1.07 psi/ft), and the maximum principal stress sHmax (1.2 psi/ft to 1.7 psi/ft) in NW-SE compressional direction is significantly greater than the vertical stress, which therefore is the intermediate principal stress.IntroductionThe stress field in crustal rocks can be investigated by means of direct measurements methods, which include strain relief overcoring, and hydraulic fracturing techniques, or by using several techniques that describe the orientation and magnitude of the stress tensor. These include borehole breakouts, tensile fractures in the borehole walls and leak off tests. The knowledge of the in situ regional or local stress magnitudes and directions is essential to establish the tectonic stress regimen of the basin and the stress field changes induced for opened deep construction, excavation in the rock masses and drilling petroleum wells. The local stress field is disturbed, and new stress field is induced in the neighborhood of the excavation, therefore the stress tensor is relevant information for the design of the processes and construction of the subterranean projects. To study the in situ stress state of the Eastern Cordillera of Colombia is the subject of the present investigation. The geological settings and configuration of the Eastern Cordillera evidence an active compressive tectonic in the most recent geological times. Two special sites were selected in the foothills located in the Cusiana and Cupiagua fields and the Hydroelectric project in Sogamoso River, where important engineering projects have been carried out that involve excavations or deep drillings, Torres, M. E.(2001). The Overcoring technique was used inside an exploratory gallery built to 190 m of depth. The 4 remaining methods were used in depths between 13.000 and 16.000 feet (3.962 - 4.878 m), and distributed in tests carried out in the deposits of hydrocarbons at the Cusiana and Cupiagua fields of BP Exploration. Hydraulic fracturing was analyzed in two wells of the Cusiana field. Borehole breakouts were studied on one well in the Cusiana field and ten wells within the Cupiagua field. Hydraulic fracturing and induced tensile wall fractures were analyzed on two wells in the Cusiana field. The revision of leak off tests performed for fifty-two wells in both the Cusiana and Cupiagua fields. In order to use the knowledge of the stress induced around underground excavations, it is necessary to have intact rock samples laboratory tested to determine the rock mechanics parameters. A series of mechanical uniaxial and triaxial compression tests and Brazilian tests were conducted on reservoir rocks from Fm Mirador, Fm Barco and Fm Guadalupe. The final results presents the principal stress tensor s1, s2 y s3 and their direction, deduced by each one of the techniques employed. Stress direction inferred from the induced tensile fractures and breakouts elongation denoted these stress states according to the geological setting. Keywords: leak, eastern cordillera, fracture, stress direction, gradient, upstream oil & gas, hydraulic fracturing, magnitude, principal stress, cusiana field Subjects: Hydraulic Fracturing, Reservoir Characterization, Reservoir geomechanics This content is only available via PDF. 2003. 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