UNIVERSIDAD MAYOR DE SAN ANDRS FACULTAD DE INGENIERA INGENIERA PETROLERA

PRACTICA N 4

MATERIA: PET-103

DOCENTE: ING. RODOLFO AYALA

UNIV.: PATRICIO QUISPE TARQUI

FECHA: 12 de junio, 2012

La Paz Bolivia

PRACTICA PROSPECCIN GEOFSICA

EJERCICIO 1: PERFILES GEOELECTRICOSSe han realizado 6 perfiles en el Valle de un rio de acuerdo al corte geolgico mostrado en la Figura 1. Tambin se perforo un pozo de sondeo que muestra que el primer estrato de 8 metros de espesor est compuesto de areniscas parduzcas; el segundo estrato de 41 m de espesor est formado de gravas finas a gruesas, y el tercer estrato de 7 m de espesor est formado areniscas finas y el basamento est compuesto de rocas granticas, con fines investigativos.

Figura 1. Perfil geolgico y posicin de los perfiles geoelctrico (nmeros) y del pozo perforado.

Los datos de cada perfil geoelctrico de la resistividad aparente versus AB/2 son mostrados en la Figura 2.

Figura 2. Curvas de la resistividad aparente (CRA) y la resistividad verdadera (CRV) de loa 6 perfiles.

Utilizando el programa VES modelizar cada una de las curvas y verificar la interpretacin del perfil geolgico mostrado en la Figura 1 es la correcta.

REALIZACIN DE LOS PERFILES POR ELPROGRAMA VES.-Utilizacin del programa ANGOSTO DE ANDALUCA SEV-3a) Datos Inicialesb)Datos FinalesLayerThicknessResistivity

12341.855.2045.00infinite242.8010.060.00400.00

LayerThicknessResistivity

11.40250.00

20.9090.00

36.5012.00

410.0095.00

530.0045.00

6infinite800.00

AB/2 Observed Resistivity Calculated Resistivity------------------------------------------- 2.00 200.0 197.2 3.00 150.0 143.5 4.00 90.0 95.4 5.00 55.0 61.0 6.00 40.0 40.2 8.00 22.0 21.9 10.00 19.0 18.2 13.00 21.0 19.2 15.00 23.0 20.9 20.00 28.0 25.2 24.00 30.0 28.4 32.00 37.0 34.2 38.00 40.0 38.0 50.00 44.0 45.2 65.00 54.0 53.7 80.00 64.0 62.1 100.00 75.0 73.2 130.00 87.0 89.5 AB/2 Observed Resistivity Calculated Resistivity----------------------------------------------2.00 200.0 195.03.00 150.0 138.24.00 90.0 91.55.00 55.0 59.66.00 40.0 40.48.00 22.0 23.410.00 19.0 19.813.00 21.0 20.615.00 23.0 22.320.00 28.0 26.824.00 30.0 30.132.00 37.0 35.938.00 40.0 39.750.00 44.0 46.365.00 54.0 54.080.00 64.0 61.8100.00 75.0 72.7130.00 87.0 89.5 GRAFICA INICIAL

GRAFICA MADIFICADA

ANGOSTO DE ANDALUCA SEV-4

a) Datos Inicialesb)Datos Finales

LayerThicknessResistivity

1

2

3

41.70

16.50

20.00

infinite520.00

25.00

56.00

87.00

LayerThicknessResistivity

10.70600.00

21.30390.00

31.0037.50

42.1015.00

511.0025.00

622.0060.00

732.0027.00

8infinite1000.00

AB/2 Observed Resistivity Calculated Resistivity----------------------------------------- 2.00 400.0 407.6 3.00 300.0 286.3 3.90 190.0 192.8 4.90 120.0 119.5 5.90 75.0 76.4 8.00 40.0 37.8 10.00 30.0 28.9 13.00 26.0 25.9 16.00 27.0 26.1 20.00 28.0 27.1 24.00 30.0 28.6 32.00 32.0 32.0 40.00 35.0 35.5 50.00 40.0 39.7 65.00 45.0 45.1 80.00 48.0 49.6 100.00 55.0 54.7 150.00 64.0 63.5

AB/2 Observed Resistivity Calculated Resistivity-------------------------------------------------2.00 400.0 405.93.00 300.0 283.03.90 190.0 195.14.90 120.0 126.55.90 75.0 82.38.00 40.0 39.310.00 30.0 28.713.00 26.0 25.616.00 27.0 26.320.00 28.0 27.824.00 30.0 29.532.00 32.0 32.940.00 35.0 35.950.00 40.0 39.065.00 45.0 42.880.00 48.0 46.4100.00 55.0 51.6150.00 64.0 67.7

GRAFICA INICIAL

GRAFICA MADIFICADA

ANGOSTO DE ANDALUCA SEV-5

a) Datos Inicialesb) Datos Finales

LayerThicknessResistivity

123451.0019.0018.0045.00infinite500.0012.0055.0055.00205.00

LayerThicknessResistivity

10.90480.00

21.0070.00

35.009.50

46.0019.00

515.0037.00

640.0026.00

7infinite800.00

AB/2 Observed Resistivity Calculated Resistivity---------------------------------------------------- 2.00 220.0 224.93.00 93.0 92.6 4.00 48.0 37.8 5.00 23.0 22.6 6.00 18.0 15.9 8.10 12.5 12.5 10.00 12.7 13.2 12.50 14.0 13.3 14.00 16.0 13.3 20.00 18.0 14.7 23.00 20.0 15.7 32.00 22.0 18.6 40.00 23.0 21.3 50.00 24.0 24.6 65.00 30.0 29.1 83.00 31.0 34.1 100.00 38.0 38.5 120.00 43.0 43.6 140.00 53.0 48.4

AB/2 Observed Resistivity Calculated Resistivity----------------------------------------------------2.00 220.0 217.53.00 93.0 98.84.00 48.0 45.45.00 23.0 26.96.00 18.0 17.78.10 12.5 12.510.00 12.7 13.412.50 14.0 14.214.00 16.0 14.620.00 18.0 17.323.00 20.0 18.632.00 22.0 21.640.00 23.0 23.950.00 24.0 26.365.00 30.0 29.583.00 31.0 33.5100.00 38.0 37.6120.00 43.0 42.9140.00 53.0 48.6

GRAFICA INICIAL

GRAFICA MADIFICADA

ANGOSTO DE ANDALUCA SEV-6

a) Datos Inicialesb) Datos Finales

LayerThicknessResistivity

12341.002.5030.00infinite25.0023.5080.00140.00

LayerThicknessResistivity

11.7028.00

21.109.00

31.1044.00

411.0091.00

518.5074.00

649.00105.00

7infinite250.00

AB/2 Observed Resistivity Calculated Resistivity---------------------------------------------------- 2.00 24.5 25.1 3.00 25.0 25.9 3.90 27.0 27.3 5.00 29.0 29.7 6.00 30.0 32.1 8.40 38.0 38.0 10.00 42.0 41.7 12.50 49.0 46.7 15.00 52.0 50.9 20.00 60.0 57.6 24.00 63.0 61.7 32.50 69.0 68.6 40.00 74.0 73.4 50.00 80.0 78.9 64.00 82.5 85.6 82.00 90.0 93.1 100.00 100.0 99.5 120.00 105.0 105.3 140.00 110.0 110.0

AB/2 Observed Resistivity Calculated Resistivity-----------------------------------------2.00 24.5 25.73.00 25.0 23.83.90 27.0 23.15.00 29.0 23.86.00 30.0 25.48.40 38.0 30.710.00 42.0 34.312.50 49.0 39.515.00 52.0 43.920.00 60.0 51.124.00 63.0 55.632.50 69.0 62.940.00 74.0 67.750.00 80.0 72.864.00 82.5 78.782.00 90.0 85.8100.00 100.0 92.6120.00 105.0 100.0140.00 110.0 107.1

GRAFICA INICIAL

GRAFICA MADIFICADA

ANGOSTO DE ANDALUCA SEV-7

a) Datos Inicialesb) Datos Finales

LayerThicknessResistivity

10.9036.00

20.5013.00

32.408.00

414.00180.00

514.5040.00

6infinite1000.00

LayerThicknessResistivity

12341.002.0027.00infinite30.008.00100.00250.00

AB/2 Observed Resistivity Calculated Resistivity---------------------------------------------------- 2.00 20.0 20.1 3.00 16.0 15.9 4.00 14.0 15.2 5.10 15.0 16.7 6.00 16.0 18.5 8.00 21.0 22.9 10.00 22.5 27.3 12.50 31.0 32.3 14.50 38.0 36.0 19.00 47.0 43.4 23.00 52.0 49.3 32.50 60.0 61.3 40.00 69.0 69.5 50.00 80.0 79.5 63.00 93.0 91.2 80.00 105.0 105.1

AB/2 Observed Resistivity Calculated Resistivity----------------------------------------------------2.00 20.0 22.33.00 16.0 16.24.00 14.0 14.35.10 15.0 14.96.00 16.0 16.18.00 21.0 19.910.00 22.5 24.112.50 31.0 29.114.50 38.0 32.819.00 47.0 40.523.00 52.0 46.532.50 60.0 58.540.00 69.0 66.450.00 80.0 75.763.00 93.0 86.780.00 105.0 101.0

GRAFICA INICIAL

GRAFICA MADIFICADA

ANGOSTO DE ANDALUCA SEV-8

a) Datos Inicialesb) Datos Finales

LayerThicknessResistivity

10.8018.00

20.4045.00

30.9012.00

43.0022.00

54.5077.00

612.00120.00

720.00105.00

8infinite550.00

LayerThicknessResistivity

12340.203.5027.00infinite20.0018.5070.00600.00

AB/2 Observed Resistivity Calculated Resistivity---------------------------------------------------- 2.00 21.0 19.0 3.00 22.0 19.8 4.00 22.0 21.1 5.00 21.0 22.9 6.00 23.0 24.8 8.00 28.0 28.9 10.00 29.0 32.9 13.00 35.0 38.3 17.00 41.0 44.3 20.00 48.0 48.2 25.00 53.0 54.2 33.00 65.0 63.1 41.00 81.0 71.8 50.00 90.0 81.9 65.00 105.0 99.2 82.00 115.0 118.8

AB/2 Observed Resistivity Calculated Resistivity----------------------------------------------

2.00 21.0 21.13.00 22.0 21.34.00 22.0 21.45.00 21.0 22.06.00 23.0 23.18.00 28.0 26.210.00 29.0 29.813.00 35.0 35.317.00 41.0 42.320.00 48.0 47.125.00 53.0 54.533.00 65.0 65.041.00 81.0 74.550.00 90.0 84.465.00 105.0 100.282.00 115.0 117.6

GRAFICA INICIAL

GRAFICA MADIFICADA

EJERCICIO 1: RESISTIVIDAD ELECTRICAProblema 1. MODELO DE CAPAS HORIZONTALES

Se realizo un SEV (Sondeo Elctrico Vertical), con un arreglo Schlumberger, que dio los resultados mostrados en el cuadro a continuacin. Usando tanto el Grafico 1 y el programa VES, calcular el modelo que ajusta los datos medidos.

Solucin:Introducimos los datos al programa VES, en modo interpretacin automtica.

Observando el grafico obtenido por el programa VES se tiene el siguiente modelo:

Capa Resistividad [ohm]Espesor [pies]

superior50.017.5

intermedia644.6505.3

inferior448.5Semi infinito