GEO Petróleo 17

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ACGGP / Publicación No.17 / Octubre de 2012

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Structural Linking of the Recetor and Piedemonte Areas Eastern Cordillera, Colombia XI Simposio Bolivariano Exploración Petrolera en las Cuencas Subandinas Fondo Corrigan - ACGGP - ARES CONVOCATORIA 2013 (XI edición)

jUNTA DIRECTIVA ACGGP 2012 Presidente Cesar Mora GEMS S.A.

Octubre de 2012

Vicepresidente Técnico Diógenes Rovira Cepcolsa

EDITORIAL

Vicepresidente Administrativo Juan Carlos Pineda CGL SAS.

Editor Roberto Linares - Equion Energía editor@acggp.org ACGGP Directora Administrativa Cristina Martínez acggp@acggp.org Diseño y producción

ideko SAS Calle 85 No. 22 - 73 PBX: 482 95 95

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PORTADA

Secretaria Marcela Mayorga OGX

EVENTOS

Tesorero Ivan Leyva Pacific Rubiales Energy

corrección de estilo Enrique Castañeda R. Impresión Intergráficas S.A.

Asociación Colombiana de Geólogos y Geofísicos del Petróleo Calle 72 No. 5 - 83 oficina 902 Tels. 2558777 / 2558966 Fax. 3454361 acggp@acggp.org

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ESTUDIANTIL

fotografía Bigstockphotos ACGGP

SUCESOS

diagramación Laura Torres William Velásquez

Intensa Actividad

Técnica

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Conferencia Técnicas

preciados colegas, pasados ya seis meses desde que asumí como vicepresidente técnico de la ACGGP, me encuentro gratamente sorprendido por toda la actividad al interior de nuestra Asociación, las excelentes relaciones que esta sostiene con diversas entidades nacionales e internacionales y el alto nivel técnico de los eventos en los cuales se ha venido participando

Structural Linking of the Recetor and Piedemonte Areas, and Implications for Hydrocarbon Accumulations, Eastern Cordillera, Colombia

Entre las actividades técnicas y científicas más relevantes de este corto periodo podemos mencionar: La presentación de siete conferencias en nuestro espacio charlas técnicas de la ACGGP, destacando la participación de varios “SEG Distinguished Lectures” y la proyección la película realizada por el Smithsonian “Titanoboa, monster snake”. Nuestra partición como Asociación en la “Exhibition 2012” – Copenhagen, de la EAGE, tuvo uno de los stand más visitados. Nuestro evento magno, el Simposio Bolivariano de Exploración Petrolera en las Cuencas Subandinas con sede en Cartagena de Indias, superó todos los pronósticos de participación, por lo cual su comité organizador merece todo nuestro aplauso y reconocimiento.

XI Simposio bolivariano

Fondo Corrigan - ACGGP - ARES CONVOCATORIA 2013 (XI edición)

Foto Portada Vista aérea anticlinal del Morro, Fotografía tomada por Hector Aguirre.

Diógenes Rovira González

Ya estamos listos para la participación en el “Anual Meeting de la SEG” – Las Vegas y se está trabajando a nivel de Latinoamérica brindando todo el apoyo de la parte técnica al evento de la AAGP, “ICE -2013” – Cartagena. Así mismo, continuamos apoyando a nuestros capítulos estudiantiles con la actividad del Geólogo visitante y a través del fondo Corrigan brindamos patrocinio a las tesis de pregrado, maestría y doctorado de los estudiantes inscritos en los departamentos de Ciencias Geológicas de Colombia y a geólogos colombianos inscritos en universidades en el exterior cuyo trabajos estén relacionados con la Geología de Colombia.

En nombre de toda la Junta Directiva quiero agradecer a las compañías que por intermedio de sus planes corporativos apoyan nuestros eventos, a todos los asociados por su activa participación en las conferencias técnicas y a los capítulos estudiantiles por la difusión de nuestra Asociación en sus universidades.

Por último, para cerrar con broche de oro la intensa actividad técnica llevada a cabo por la Asociación durante el año 2012, quiero invitarlos a que nos acompañen a pasar una exquisita velada en la GRAN FIESTA DE FIN DE AÑO de LA ASOCIACIÓN COLOMBIANA DE GEÓLOGOS Y GEOFÍSICOS DEL PETRÓLEO, el día 24 de Noviembre en el Carmel Club.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Octubre de 2012

Comunicado de Prensa Organismo sin ánimo de lucro que agrupa a los profesionales del área de la geología vinculados a la industria del petróleo, y que promueve el conocimiento técnico, así como la investigación científica dentro de esta área, se permite comunicar al público en general la gran preocupación del gremio por la “Reforma Migratoria” anunciada por el gobierno.

BITACORA EVENTOS

La reforma planteada al Decreto 4000 de 2004 busca eliminar varios requisitos que en la actualidad son exigidos a los profesionales que buscan ingresar al país con fines laborales, y la cual va en contravía de la defensa del empleo nacional. Con estos cambios el gobierno busca facilitar el ingreso de profesionales foráneos y como gremio consideramos importante que los requisitos exigidos a la fecha continúen vigentes, tales como la Licencia Especial Temporal o Permiso Temporal, así como también los contemplados para la obtención de la visa por parte de los geólogos extranjeros.

La ACGGP apoya el desarrollo de la industria de hidrocarburos en Colombia, y con ella la inversión extranjera que tanto beneficio le trae al país y a las diversas regiones donde lleva a cabo operaciones, pero igualmente considera que en Colombia existen profesionales altamente capacitados para afrontar los retos actuales, con un alto desempeño y excelente preparación académica, razón por la cual el Gobierno debe velar por la prevalencia de los profesionales nacionales frente a los extranjeros.

Teniendo en cuenta que el derecho al trabajo de los colombianos se encuentra consagrado en el artículo 25 de la Constitución Política , hacemos un llamado al Gobierno Colombiano para que cualquier modificación al actual Estatuto Migratorio, propenda por la defensa del derecho al trabajo de los nacionales y de los intereses de los colombianos.

Conferencias técnicas

miércoles 18 de Julio de 2012

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Data Analytics and Multivariate Statistics: Robust Methods for True Integration of Exploration and Production Data

ver-growing amounts of data and information, and the need to identify patterns, establish relationships, and to rapidly and robustly predict future outcomes from these data have caused tremendous interest in analytical tools in many industries. Increased computational power and modern robust statistical methods together create the potential to make these tools available to non-statisticians. Fit-for-purpose analytics are becoming commonplace in the financial sector and are beginning to emerge in the upstream oil and gas industry. Universities now offer specialized master’s degrees in data analytics, and oil companies are adding statisticians to exploration and development asset teams.

Histograms are commonly used to understand the data quality, distribution and outliers for a single variable. Similarly, cross-plots are useful for understanding relationships between pairs of variables. These familiar tools are useful for finding simple relationships between small numbers of variables; more powerful tools are necessary for investigating systems with tens, if not hundreds, of vari-

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ables – multivariate statistical techniques are such tools. These techniques include classification and regression to understand how the data cluster into natural patterns (e.g. facies, reservoir quality, completion practices) and for prediction of variables of interest (e.g. porosity, permeability, estimated ultimate recovery). To glean maximum information from potentially hundreds of attributes (e.g. seismic attributes, well logs and production data) requires tools for analyzing data redundancy and for meaningfully reducing the number of variables.

To promote wide usage of analytics in exploration and production, analytical tools must be integrated into a comprehensive E&P workstation and must be simple and natural for non-specialist geoscientists and engineers to use and understand. I will show examples of data quality control, outlier identification, multi-collinearity analysis for data reduction, unsupervised and supervised classification and non-linear regression for well log, well zone, seismic and production data. Practical knowledge and integrated tools for data analytics and multivariate statistical applications are becoming required parts of the exploration and development toolkit.

miércoles 19 de septiembre de 2012: “El control de los regímenes tectónicos en Los Andes y en sus cuencas subandinas” CONFERENCISTA: Dr. Víctor A. Ramos

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esde hace varios años sabemos que la subducción de corteza oceánica por debajo de la litosfera continental no siempre está asociada a un régimen compresivo. Hay numerosos ejemplos que muestran una alternancia entre contracción y extensión en diversos sectores del sistema de subducción. Se analizan los controles principales controlados por la cinemática de la placa cabalgante, por el sistema climático imperante en el antearco y por la flotabilidad de la losa oceánica. Este análisis permite una mejor comprensión de la evolución tectónica de las cuencas subandinas y permite entender su evolución temporal a través de toda la cordillera andina.

William M. Bashore* Transform Software and Services, Inc Littleton, Colorado, USA * William M. Bashore has been associated with the oil and gas industry for 33 years. After receiving baccalaureate degrees in Geophysics and in Geology and a master’s degree in Geophysics from the University of Utah, Mr. Bashore spent 12 years with Chevron Corporation in both operations and research. He resigned from Chevron to co-found Reservoir Characterization Research and Consulting, Inc. (RC Squared), which specialized in stochastic reservoir modeling and other geostatistical applications.

He has given many talks and seminars and numerous publications on multidisciplinary data integration, stochastic seismic inversion, and reservoir modeling. In 2005, he joined Transform Software and Services, Inc., where he is a lead software developer in the areas of multivariate statistics, seismic inversion and other seismic processing techniques. Mr. Bashore also holds a Master’s in Business Administration from California State University, Fullerton.

Patrocinada por Beicipfranlab Imágenes integradas 2

jueves 27 de septiembre de 2012: Image Ray Time-to-Depth Conversion and Model Ray Applications Presented by Eduardo Filpo, Petrobras

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lthough the use of prestack depth migration (PSDM) images has become a standard procedure recently, the imaging in time, associated with timeto-depth conversion, is still largely used for two reasons: lower cost in computational terms and it does not need an extremely accurate velocity field. Time-to-depth conversion using Dix inversion and vertical-stretching algorithms have restricted applicability because they are based on the assumption of one-dimensional seismic models.

In this lecture, I explore the concept of image rays to present techniques that assume threedimensional, smoothed seismic models, which are much more geological. The key is to apply an image-wavefront construction algorithm that uses the velocity field in time. This algorithm is used not only to trace rays and wavefronts, but also to convert the time velocity field to depth.

The set of image rays and its corresponding wavefronts establish a curvilinear coordinate system that can be applied to solve problems associated with conversion from time-to-depth and vice versa. In this perspective, the time-to-depth conversion of seismic attributes can be performed as a simple coordinate transformation in which a vertical grid line of the Cartesian system (seismic trace) is mapped into an image ray and a horizontal line (time slice) into an image wavefront.

In the inverse problem (i.e., the depth-totime conversion), vertical grid lines in depth are mapped into curves in the time domain. These curves are determined by a differential equation that is very similar to the eikonal equation.

Because of this similarity, I suggest denominating them model rays. Model ray tracing can be applied to solve several problems related to depthto-time conversion, such as building synthetic seismograms, time conversion of PSDM images, well calibration, and construction of hybrid migration algorithms.

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PORTADA

Asociaci贸n Colombiana de Ge贸logos y Geof铆sicos del Petr贸leo

Octubre de 2012

Structural Linking of the Recetor and Piedemonte Areas, and Implications for Hydrocarbon Accumulations, Eastern Cordillera, Colombia

in northeastern Recetor and Piedemonte (to the northeast of Cupiagua) is often at high rates and indicates substantial reserves in this area with limited development to date. The producing formations are typically at depths of 14000 to 18000 feet.

The high production rates (and high cumulative production) are possible due to the combination of thick, clean, quartzose sandstones retaining matrix permeability at low porosities (3-6%), and the presence of several pervasive intersecting sets of natural fractures, displayed in image logs and cores (Figure 2).

Copyright 2012, ACGGP This paper was selected for presentation by an ACGGP Technical Committee following review of information contained in an abstract submitted by the author(s).

Introduction The frontal zone of the Eastern Cordillera fold and thrust belt hosts the large fields of Cusiana and Cupiagua that have a long history of production, and as well, there is newer production from thrust sheets to the northeast, in the Recetor, Piedemonte and Niscota blocks (1, 2, 3). The area is structurally complicated and good seismic imaging has proven difficult to obtain in the areas northeast of the Cupiagua-main Recetor structural complex.

Effective exploration and development rely on a detailed structural modeling workflow of 2D and 3D balancing, based heavily on well data, in order to achieve a structurally valid 3D seismic interpretation. Drilling based on the resulting 3D structural model has proven successful.

The focus of this paper is the structural transition from the main Recetor area to the Piedemonte area. The structural style and trend of the productive and prospective thrust sheets change from the Recetor area to the Piedemonte area. In the main Recetor area, there is one primary producing thrust sheet with limited stacking of the Mirador and other reservoir units. In contrast, from northern Recetor through the Piedemonte area and continuing into the Niscota area there are stacked sheets of the producing reservoirs, with the sheets increasing in number to the northeast, corresponding to increased shortening in the northeastern

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part of the area in discussion. The overlying Nunchia syncline reflects the change in style and aids in interpretation of the deeper structure. The change in trend and slip direction relates to an area with slight along-strike shortening, and this component of shortening contributes to development of culminations along strike. The structural modeling has resulted in identification of several opportunities in the area, as well as providing a guide to well planning and reserve estimations.

Location and Setting

The Recetor-Piedemonte-Niscota area is located in the Llanos foothills, on the eastern edge of the Eastern Cordillera and it is the frontal deformed zone adjacent to the Llanos foreland basin (Figure 1). The Cupiagua and Cusiana fields are immediately southwest of this area, in the same frontal thrust zone of the Eastern Cordillera fold and thrust belt. All the fields produce from naturally fractured, generally low porosity sandstone reservoirs of the Paleogene Mirador, Barco and Upper Cretaceous Guadalupe Formations.

The production from the Cusiana and Cupiagua fields has been substantial, with more than 600 MMBO produced from Cusiana and more than 350 MMBC produced from Cupiagua (which includes production from part of the Recetor anticline). The production from better wells

Figura 1 Oblique aerial view (to north) of Google 3D terrain model, showing location of the Recetor-Piedemonte complex (yellow area) in The Llanos foothills, along the southeastern limit of the Eastern Cordillera.

Structurally, the producing zones are from reservoirs in an antiformal duplex stack of thrust sheets.

In the Recetor area nearest to Cupiagua anticline, there is one main thrust sheet, but this changes, progressively adding more sheets to the antiformal stack to the northeast. The multiple thrust sheets reflect the progressive increase in shortening in the frontal zone to the northeast. Wells typically encounter reservoir section in more than one thrust sheet. The thrust sheets are laterally extensive, ranging from ten to tens of kilometers in strike length.

Each thrust sheet typically has an anticline formed parallel to the thrust, and a longer backlimb, which is a common geometry in fold and thrust belts in general. The production typically indicates good hydraulic connectivity along strike.

Figura 2 Top image: sample of image log, showing fractures at several distinct orientations. Bottom image: view of core, showing pervasive fractures approximately perpendicular to core axis on left side, and other fractures at low angles to core axis on right side.

Data and Seismic Data Quality 3D seismic surveys as well as an older network of 2D seismic lines cover the area. Ten Liria wells are distributed along the main Recetor anticline and some (7) Cupiagua wells also aid in defining the Recetor structure at its SE end. To the northeast, 14-15 wells control the structures of the Piedemonte area, with a couple more wells in Niscota block. The Recetor and Piedemonte wells range over a distance of approximately 50 km along the trend of the foothills zone. Several wells have cores and there is structural data from image logs, typically over very limited intervals, in a number of the Liria and Piedemonte wells. Surface geology provides an additional important constraint in this area, as this is the youngest and currently active part of the deformation in the Eastern Cordillera.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Well production, pressure and tracer data also aid in understanding the hydraulically connected extent of the thrust sheets.

The area of Cupiagua to Niscota is covered by five separate 3D seismic surveys. These have been merged into different PSDM (pre-stack depth migrated) volumes and two of these merged volumes, covering Cupiagua-Recetor and Recetor-Piedemonte, are the basis for the work presented here. The area of Cupiagua and the main part of Recetor are well imaged. The area covered in the northern Recetor survey was narrow and thus this area is not well imaged. Due to the increasing structural complexity into northern Recetor and Piedemonte, the imaging is not good in this area (Figure 3). Reprocessing is in progress in an attempt to improve the seismic imaging in this area. The Niscota volume to the northeast shows somewhat better imaging than Piedemonte, but there is also much uncertainty in the seismic image in this area.

Octubre de 2012

Structural Modeling Applying a detailed structural modeling workflow yields a viable and tested fault network, and leads to a robust, structurally valid 3D model.

This process overcomes, to some degree, the limitations of the seismic imaging.

A network of sections that pass through all the wells insures that the well data is used to its maximum extent in constraining the balanced sections. Well tracks, formation tops and structural data are projected onto the sections, along with appropriate surface structural orientation data, with care taken to project structural orientation data correctly and to limit projection distance.

The sections must be extended beyond the limits of the 3D seismic data in order to constrain key aspects of the balancing. Surface data and 2D seismic data aid greatly in controlling the interpretation of the extended parts of the sections.

The sections are interpreted in detail, starting from the best-controlled areas. Through numerous iterations, the sections are tested for balance, adjusted, retested, through the iterations necessary until a valid, balanced section is achieved. The sections are of course oriented in or very near the transport direction, as this is a fundamental assumption for 2D section balancing. Forward modeling also contributes to achieving valid balanced sections as it further tests the kinematic sequence of deformation.

Faults, other structural elements and horizons are carried from section to section, adjusted progressively as the data indicates, in order to insure 3D consistency. This process is necessary because of the low quality of the seismic image.

Attempting to interpret directly in the 3D volume, without the validated sections, yields many structural inconsistencies and thus would yield a 3D model that is structurally invalid. The network of tested, balanced sections provides the template, most significantly of a valid fault network, which allows a structurally consistent 3D interpretation.

Applying this process, the uncertainty on the model has been reduced considerably.

Key Structural Elements and Balanced Sections. In the area there are several structural elements important to section balancing that are well constrained or at least better constrained than some other parts of the sections (Figure 4).

These elements include regional levels in the foreland, the Nunchia syncline, which is exposed on the surface and is well imaged, and known positions of Mirador (to Guadalupe) sections in thrust sheets, from well data.

Regionals of several key units are controlled by a few wells that pass into the foreland section, as well as by correlations on 2D seismic lines from wells in the foreland to the foreland immediately Figura 4 Balanced sections. Blue horizon is the Leon Fm. Yellow to green interval is the Mirador to Guadalupe section. Faults are red. Azimuth to right is 115 (southeast). Scale is 1:1. Top of each section shows horizontal scale in meters. Vertical white bar is 10,000 ft (3048 m). Blue (Leon) horizon shows shape of Nunchia syncline, which is detached from the deformation of the Mirador-Guadalupe section below. Leon, Mirador and Guadalupe Fms. foreland regionals are shown on right part of both sections. Upper section: main Recetor anticline and with one primary producing thrust sheet, thickened by backthrusts. Lower section: northern part of Recetor anticline. Note additional stacking and thickening of Mirador-Guadalupe section here.

in front of the thrust zone. These regional levels allow understanding of the amount of uplift of the corresponding units in the thrusted zone, either in the Nunchia syncline or in the thrust sheets.

The Nunchia syncline is exposed on the surface where it is defined by Guayabo, Leon and in part, Carbonera Formations. To the southwest in the area of the Cupiagua field, the syncline at the surface becomes a northwestward dipping monocline (the trough line disappears beneath the thrust bounding the syncline to the northwest).

The shape of the syncline provides clues as to the deformation beneath, and it also provides an estimate of frontal cutoffs that narrow the range on the total displacement of the younger units in the syncline on the basal Yopal fault.

The well intersections with Mirador, Barco and Guadalupe units, as well as thrust faults, provide anchor points from which one can begin to interpret the stacked thrust sheets and the faults that bound them. Most of the units increase in stratigraphic thickness to the west, as determined primarily from wells.

Figure 4 shows two examples from the network of balanced sections. The upper image is from the area to the southwest, over the main Recetor anticline where it is well imaged and well controlled by wells. The lower is from the northern Recetor area, where the complexity is increasing in the Mirador-Guadalupe section. Figure 5 shows the location of the two sections.

Figura 5 Map view of the various Mirador thrust sheets of the productive zone. The colors indicate different thrust sheets or segments of thrust sheets. The two white lines indicate the location of the sections in Figure 4. The blue oval highlights the structural transition zone that is the main focus of this paper.

Grid is 10 km x 10 km.

Figura 3 Upper image: detail of sample line from SW part of Recetor structure where image quality is very good. Recetor anticline and fold, backthrusts, syncline and foreland all very well imaged. Lower image: detail of sample line from NE part of Recetor area where image quality has degraded greatly. Recetor anticline is barely visible. The only part in this line that is still well imaged is the overlying syncline. The reservoir section is from the yellow marker (Mirador Fm.) to the green marker (Guadalupe Fm.) on the wells.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

The primary deformation type in this compressional thrust belt is flexural slip, especially for the more rigid units, and this is the primary type of restoration method applied.

Change in Structural Style. The sections show a distinct change in structural style, with the most significant change occurring somewhat abruptly in the northern part of Recetor. The change in shape of the Nunchia syncline reflects changes in the deeper, reservoir-containing section. Figure 6 shows sections from southwest to northeast that illustrate the change in shape of the Nunchia syncline, along with changes in the deeper thrusted sections.

The blue horizon (Leon Fm.) shows the changes in the syncline shape well. The syncline is asymmetric, with a long dipping forelimb in section A. In section B, the base of the syncline has been uplifted considerably, and it has a somewhat more symmetric shape. Section C is similar to B in shape, but the syncline is uplifted even more.

Sections D and E are similar, except with the backlimb folded up and displaying a strong dip to the southeast. In sections D and E, the SE-tilted backlimb accounts for approximately half or more of the extent of the syncline. Note that sections C, D and E are quite close together, and this is the area of the rather abrupt structural transition to the long, folded and tilted backlimb of the Nunchia syncline, and accompanying development of the high amplitude, overturned, fault-propagation El Morro fold (the trailing thrust sheet beneath the syncline).

The change in shape of the syncline results from (or corresponds with) the change in stacking and shortening of the sub-syncline section of Carbonera C7 through Mirador to Guadalupe. Section A shows a long frontal thrust sheet of Mirador-Guadalupe, with minor backthrusting.

A second trailing sheet helps drive the displacement and limited uplift above regional of the base of the syncline. In section B, the Mirador-

Figura 6 Sections from SW part of Recetor to the structural transition zone in northern Recetor block, showing the change in shape of the Nunchia syncline and the changes in stacking of Mirador-Guadalupe thrust sheets below. Leon Fm. is blue horizon. MiradorGuadalupe section is the yellow to green horizon. Faults are red.

Azimuth to right is 115 (southeast). Scale is 1:1 vertical: horizontal. Approximate location of sections shown in Figure 7. Section E is only partially interpreted, as the transport direction has changed and a different orientation is required for a balanced section.

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Junio de 2012

Figura 7 Map view of Mirador thrust sheets from 3D model, color mapped for depth, and showing the location of the sections A-E in Figure 6.

Guadalupe sheets, which also include C7 and C8 members of the Carbonera Fm., are stacking and thickening much more, and this uplifts the base and back of the syncline. This thickening and stacking continues to develop in section C. Both sections B and C have more displacement on the backthrusts in the main Recetor thrust sheet, which also thickens the thrusted sequence. In section D, the El Morro fold begins to develop as a higher amplitude feature. It is the trailing thrust sheet beneath the syncline seen best in sections D and E. An additional thrust sheet between the main frontal sheet (of Recetor anticline) and El Morro fold begins to develop in section B, with increased displacement in sections C-E. This sheet is necessary for balance, in order to have sufficient shortening of the Mirador-Guadalupe section to achieve the uplift and shape of Nunchia syncline. Just northeast of section E, the high amplitude, overturned geometry of El Morro anticline is proven by a well, and two producing thrust sheets below are also proven. The backthrusting appears to end, in favor of the forethrusted duplexes, in the transition zone. The hinterland side of the seismic image (NW) is very poor, so there is uncertainty on exactly where the transition from backthrusting to forethrusted duplexes happens.

  Longitudinal Shortening. There is a distinct change in trend of the structures (fold axes, general strike of beds and faults) in the northern part of Recetor. This change is seen at the surface, but is more pronounced at the level of the frontal Mirador thrust sheet. At the level of the thrust sheets, this change in trend is in the same area where the change in style of thrusting occurs.

Figure 8 shows the change in trend of the Mirador thrust sheets, along with inferred slip directions. These inferred slip directions would suggest a small amount of along strike convergence in the frontal thrust sheets. In mapping out the 3D seismic, in a narrow zone where the image is still reasonably good and there is control from six wells, a longitudinal thrust structure is apparent in a strike view (Figure 9). This feature could be explained by an oblique ramp with displacement in the main dip slip direction causing a local repeat of the Mirador thrust section. However, mapping it out in 3D determines that it is not a result of an oblique fault segment and there actually is a small amount of shortening in the strike direction.

This thrust, along with the along strike folding in this area, suggests that there has been some minor along strike convergence in the frontal thrust zone in this area of transition. The drilled culminations that we interpret as resulting in part from

Figura 8 Map view of Mirador thrust sheets and segments of thrust sheets.

North is up, and the grid is 10 km x 10 km. Well tracks are shown in white. The transition zone is indicated by the blue oval. The strike / trend of the segments of the thrust belt are shown by the white lines, with the arrows indicating an inferred dip slip displacement in each segment.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Figura 9 Along-strike view of the northern part of Recetor anticline. Bright yellow is the interpreted Mirador horizon, controlled by most of the wells in this area. Blue lines are interpreted fault traces. Note apparent thrust overlap of the Mirador horizon in the middle of the view, as well as the folded nature of the Mirador in this strike view. The transition zone is in the area of the right third of this section.

this convergence have good production in a few wells. A second trailing thrust sheet may also have a similar folded geometry.

3D Model. The dense network of balanced sections served as a template for interpretation of the seismic data in 3D. Without this guide the uncertainty on interpreting a fault network would be very great, and as well the reservoir horizons could not be effectively interpreted. While there is some continuity of reflectors that appear to be horizons in the thrust sheets, determining extent and cutoffs is very uncertain. For faults, any direct picking is even more uncertain solely from the seismic image. Applying the sections as guides, which are based heavily on well and surface data, we can interpret a viable fault network that was tested in the sections. We can then also use the sections to guide the horizon interpretation.

The resulting 3D interpretation and model has a tested structural basis.

Figure 10 shows the frontal thrust sheets of Mirador, from Recetor through Piedemonte. The transport direction is to the right in the figure. The Liria wells in Recetor block (southern half of image) are mostly lined up along at or near the crest of the main Recetor anticline, while the Piedemonte wells (northern half of image) are more scattered in order to encounter the several thrust sheets in this area.

The next figure (Figure 11) shows only the Recetor part of the 3D model. The colored surfaces are the Mirador thrust sheets beneath the Nunchia syncline. Only two main bounding faults are displayed: the frontal fault at the base of the thrust sheets (in solid gray), and the fault that bounds the base of the Nunchia syncline (in gray

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Figura 10 Perspective view of 3D model of Recetor and Piedemonte areas. Only deeper, frontal thrust sheets are shown. Mirador horizon is color mapped for depth (blue=low, red=high). Well tracks are in white.

mesh). The change in space between these two faults goes along with the lateral change in style of the thrust sheets, with repeated sheets beginning in the transition zone on the left of the figure.

The two faults open to the left of the figure, and this is the additional space that has been filled by the stacked thrusts, including the El Morro overturned anticline on the far left of the figure (light

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

green mesh). The uplift of the Nunchia syncline is illustrated by the uplift of its basal fault progressively to the left in the figure.

Summary and Conclusions

The detailed structural modeling allows development of a constrained 3D interpretation and subsequent 3D model. This type of iterative structural balancing is essential in structurally complex areas. The surface and well data are critical in developing a tested, valid model. The structurally constrained 3D model greatly reduces uncertainty on trap extent and geometry, and it aids in understanding the range of uncertainty in reserve estimates. The model also provides a robust guide to exploration and development. The results achieved with this method show that there is substantial remaining potential in both producing and untested thrust sheets in this area.

The structural style changes from primarily one main thrust sheet with backthrusts in the Recetor area, to a forethrusted set of duplexes in the northern part of Recetor. This style continues northeastward through the Piedemonte area and into the Niscota area. The position and geometry of the overlying and detached Nunchia syncline, reflects the changes in shortening and stacking of thrust duplexes with the Mirador to Guadalupe section below. Along with the change in the style of the thrust sheets, there is a change in trend of the structures. This change in trend appears to cause, due to some component of convergence is slip directions, a slight amount of along-strike convergence, as evidenced by a minor mapped thrust in the strike direction. The transition in structural style changes

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Octubre de 2012

the geometry of the traps and understanding these changes leads to identifying new opportunites in the area, especially from northern Recetor up through the entire Piedemonte area.

References

1. Cazier, E. C., A.B. Hayward, G. Espinosa, J. Velandia, J.F. Mugniot, and W.G. Leel, 1995, “Petroleum geology of the Cusiana Field, Llanos Basin foothills, Colombia”, AAPG Bulletin, v. 79, No. 10, p. 1444-1463.

2. Cooper, M.A., F. T. Addison, R. Álvarez, M. Coral, R.H. Graham, A. B. Hayward, S. Howe, J. Martínez, J. Naar, R. Peñas, A. J. Pulham, and A. Taborda, 1995, “Basin Development and Tectonic History of the Llanos Basin, Eastern Cordillera, and Middle Magdalena Valley, Colombia”, AAPG Bulletin, v. 79, No. 10, p. 1421-1443.

3. Martínez, J., 2006, “Structural evolution of the Llanos foothills, Eastern Cordillera, Colombia”, Journal of South American Earth Sciences, v. 21, p 510-520.

Acknowledgements

We thank Ecopetrol S.A. for permission to publish these results. We also thank colleagues at Ecopetrol S.A., Equion Energy and FaultSeal for comments and discussion.

Figura 11 Perspective view of 3D model, looking to SE. Gray surface is the frontal (basal) thrust, and the gray mesh is the fault at base of the Nunchia syncline. Colors are Mirador horizon in various thrust sheets. This model is of only the Recetor part, up through the transition zone on the left (NE) side.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Octubre de 2012

SUCESOS

II TORNEO DE GOLF ACGGP

Sabía usted que…

Reconocimiento Víctor Vega En el mes de abril durante la reunión anual de la AAPG en Long Beach, el geólogo Victor Vega, Vicepresidente de Equion Energía, recibió por parte de los miembros de la AAPG un reconocimiento por la labor desarrollada en Latinoamérica con la organización de los Geoscience Technology Workshops en México, Argentina, Colombia y Brasil, así como el apoyo con el Imperial Barrel Award y los capítulos estudiantiles. Felicitaciones.

Preguntas

1. ¿Pueden crecer las rocas?

2. ¿A qué distancia puede arrastrar el viento al polvo común?

3. ¿Cuál fue el terremoto más devastador que se conoce?

4. ¿A qué velocidad puede fluir el lodo?

5. ¿Gira todo el planeta a la misma velocidad?

6. ¿Cuántos minerales se conocen?

Encuentre las respuestas al final de la revista

Con un rotundo éxito se celebro en el Karibana Beach Golf Condominium de Cartagena el II TORNEO DE GOLF ACGGP en el marco del XI Simposio Bolivariano de Cuencas Subandinas. Más de

cincuenta jugadores, vinculados a la industria del petróleo, disfrutaron de un excelente campo, enmarcado en un día fresco propicio para la practica del golf.

XI Simposio Bolivariano de Cuencas Subandinas “Integración del Conocimiento, clave del éxito”, fue el lema del “ XI Simposio Bolivariano de Exploración Petrolera en las Cuencas Subandinas”, ratificándose como el evento bandera organizado por la Asociación Colombiana de Geólogos y Geofísicos del Petróleo – ACGGP. El desarrollo de esta versión fue especial gracias a la celebración de los treinta años de existencia, razón por la cual se ofreció un merecido homenaje al creador del Simposio, el geólogo Roberto Leigh, quien manifestó su emoción al recibir la placa conmemorativa.

La Ceremonia de inauguración estuvo presidida por el geólogo Diógenes Rovira - Vicepresidente Técnico de la Junta de la ACGGP, los integrantes del Comité Ejecutivo y por el Coronel William Ruiz comandante de la policía metropolitana de Cartagena.

El XI Simposio Bolivariano ha sido el más grande hasta ahora realizado, con una nutrida asistencia de profesionales, con la mayor muestra tecnológica en su historia y el montaje de la zona ONE – Oportunidades de Negocios Exploratorios.

Se utilizó un sistema de votación interactiva que facilitó la selección de las mejores presentaciones y 30 pantallas de televisión que sirvieron para apoyar y dar realce a las presentaciones de cartelera, las cuales contaron un una nutrida asistencia.

Contamos con 115 estudiantes de 6 universidades nacionales y 1 universidad internacional, que tuvieron una importante presencia por medio de actividades técnicas y sociales diseñadas para ellos, que contribu-

18

yeron con el desarrollo profesional y social de nuestros futuros colegas.

La asistencia de altos representantes de la AAPG, SEG y EAGE es una evidencia de la integración que existe con nuestra comunidad geocientífica; estas asociaciones tienen programas educativos y de formación para profesionales y estudiantes esenciales para apalancar el fortalecimiento profesional y el éxito exploratorio en la región.

Durante la ceremonia de clausura, el Presidente de la Agencia Nacional de Hidrocarburos, Dr. Orlando Cabrales, invitó a los exploradores a generar nuevas ideas y a romper paradigmas. Finalmente, Jaime Checa – Director Técnico, resaltó la fuerza de los ideales, el motor que constituyen para el logro de los objetivos colectivos y la importancia que esto ha tenido dentro del crecimiento de la ACGGP y del Simposio.

Paralelamente al desarrollo de actividades técnicas, se contó con espacios deportivos y sociales de integración, el día domingo se llevó a cabo el II Torneo de golf ACGGP patrocinado por Pacific Rubiales, Geoespectro, ION y Mitcham.

Nuestros sinceros agradecimientos a todos los participantes, conferencistas y compañías patrocinadoras por depositar su confianza en este evento cuyas memorias son un valioso aporte de conocimientos geológicos y geofísicos, con información actual y fidedigna en exploración y explotación de hidrocarburos. A todos ellos se debe en gran parte, el éxito de estos eventos.

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VENTANA ESTUDIANTIL

Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Capítulo Estudiantil

Fondo Corrigan - ACGGP - ARES CONVOCATORIA 2013 (XI edición) Este programa, soportado por contribuciones de la ACGGP y ARES, está dirigido a apoyar: — Tesis de pregrado de los estudiantes inscritos en los departamentos de Ciencias Geológicas e Ingeniería Geológica de Colombia.

— Tesis de maestría y doctorado de los estudiantes inscritos en los departamentos de Ciencias Geológicas (Geología, Geofísica) de Colombia.

— A geólogos colombianos inscritos en universidades en el exterior cuyo trabajo de maestría o doctorado esté relacionado con la Geología de Colombia.

Sabía usted que…

La(s) propuesta(s) seleccionada(s) de maestría o doctorado recibirán un apoyo de hasta 6.000.000 de pesos m/cte (o equivalente de 3.000 dólares) y de pregrado hasta 3.000.000 de pesos m/cte. En esta convocatoria se seleccionarán: una propuesta de doctorado, dos de maestría y cuatro de pregrado. No se consideran proyectos de estudiantes que estén aplicando a universidades en el exterior o proyectos de maestría o doctorado que se en-

20

Junio de 2012

cuentren en la fase final (culminación en abril del 2013) o a candidatos que hayan recibido financiación para una propuesta del Fondo Corrigan en años anteriores.

Los estudiantes seleccionados para la financiación de tesis de pregrado deben entregarla como documento final a los seis meses y los de maestría deben hacerlo a los 12 meses. Los candidatos al título de doctorado deben presentar un informe del proyecto a los 12 meses, con la firma del director de la disertación y copia de esta cuando la culminen. Si publican los resultados de sus tesis, enviar documento final del artículo.

Para los candidatos a doctorado, el investigador debe entregar un informe a los 12 meses con visto bueno del director de proyecto. El financiamiento se otorga una sola vez por programa y al culminar el investigador debe enviar copia de su tesis de doctorado y copia de los artículos en los que se utilicen los datos adquiridos con la financiación de la convocatoria.

En las presentaciones en congresos, tesis y publicaciones los agradecimientos deben aparecer a nombre de Fondo CorriganACGGP-ARES.

2. En 1999 un estudio mostró que el polvo africano alcanza las costas de Florida, impulsado por los vientos del norte de África y transportado a una altitud de 6.100 metros, donde es capturado por los vientos transoceánicos. De igual forma el polvo de China encuentra también su camino a Norteamérica.

3. El terremoto más devastador hasta ahora registrado ocurrió en 1557 en la China central. Afectó una región donde la mayoría de los habitantes vivían en cuevas excavadas en roca blanda. Estas moradas colapsaron matando, según estimaciones, a 830.000 personas. En 1976 otro terrible temblor golpeó Tangshan, China, donde hubo más de 250.000 muertos.

Cursos ofrecidos por Norm Cooper y Yajaira Herrera Mustagh Resources regresa a Colombia en el 2013 con 5 cursos para prestar sus servicios de capacitación a su personal: Procesamiento de Datos Sísmicos Febrero 19-22, 2013 - US$ 3.250 Control de Calidad de las Fuentes, Receptoras, Patrones, Ruido y su Mitigación Julio 10-11, 2013 - US$ 1.650 Taller de Reubicación de Pozos Julio 12, 2013 -US$ 800

Respuestas 1.

Sí. Ciertas rocas, llamadas cortezas de ferromanganeso, se encuentran en montañas bajo el mar, se forman por la lenta precipitación de material en suspensión en el agua marina y crecen aproximadamente un milímetro cada millón de años.

CURSOS SÍSMICOS EN BOGOTÁ EN 2013

4. Los corrimientos de tierra y las riadas de lodo pueden moverse a velocidades superiores a los 160 km/h.

5. E l núcleo sólido interno gira más rápido que la parte externa del núcleo de hierro, el cual es líquido. Un estudio en 1996 mostró que a lo largo del siglo anterior esa velocidad extra hizo que el núcleo interior girase un cuarto de vuelta más respecto al resto del planeta. De esta forma el núcleo interno efectúa una revolución completa respecto al resto del planeta en aproximadamente 400 años. La inmensa presión hace que el núcleo se mantenga sólido.

6. S e conocen más o menos 4.000 minerales, aunque solamente unos 200 son de importancia capital. Se describen aproximadamente de 50 a 100 nuevos minerales cada año.

Norm y Yajaira han diseñado más de 3.000 levantamientos 3D en 52 países, siendo Colombia el de mayor actividad sísmica en la actualidad.

Nuestros cursos se pueden modificar para satisfacer las necesidades particulares de su compañía.

Diseño de Levantamientos 3D para Operaciones Sísmicas Terrestres Septiembre 18-20, 2013 - US$ 2.450 Geofísica para Geólogos e Ingenieros Noviembre 6-8, 2013 - US$ 2.450 Por favor contacte a Yajaira para preguntas o inscripciones: Teléfono: 1 (403) 265-5255, E-mail: yajaira@mustagh.com

Visite nuestra página web www.mustagh.com para inscripciones y temarios

Respuestas tomadas de 101 Amazing Earth Facts, por Robert Roy Britt.

21

UNITE

Asociación Colombiana de Geólogos y Geofísicos del Petróleo

Junio de 2012

Sistema Inalámbrico de Adquisición Sísmica

Becerrada de integración La Junta Directiva de la Asociación Colombiana de Geólogos y Geofísicos del Petróleo, desea expresar su más sincero agradecimiento a las diferentes compañías operadoras y de servicio por el apoyo brindado para la realización de nuestra Tradicional Becerrada de Integración, llevada a cabo el pasado 1o de Septiembre en el restaurante El Pórtico. Este apoyo es el que hace posible que cumplamos con los objetivos propuestos en pro de la comunidad Geológica y Geofísica vinculada a la industria del petróleo.

Para deleite de todos los asistentes en esta oportunidad contamos con la presencia de la orquesta La Solución, el tradicional derby asnal, y la monumental becerrada.

Las compañías que se vincularon a este evento son: VERITAS, SERCEL, DATALOG, DRILLTEK COLOMBIA SAS, GEOTRACE, CEPCOLSA, ENERGY GEOPHYSICAL, XILOPALOS, CGL, HOCOL, SATELITE SISMICA, PACIFIC, BIOSS, PETROSEIS, PETROSEISMIC, UNION TEMPORAL, MITCHAM, OGX, WEATHERFORD, INFORPETROL, CSI LTDA. y CGA LTDA.

22

UNITE está diseñado para proveer facilidad de tendido en cualquier ambiente, ya sea que se le utilice con su propio sistema de adquisición o en conjunto con el sistema 428, usando sensores analógicos o digitales.

UNITE ofrece un nivel sin precedentes de flexibilidad y control de calidad.

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Houston, USA sales.houston@sercel.com www.sercel.com

ANYWHERE. ANY TIME. EVERY TIME.

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Asociación Colombiana de Geólogos y Geofísicos del Petróleo La Asociación Colombiana de Geólogos y Geofísicos del Petróleo.

Invita a su

FIESTA

de fin de año

Sábado 24 de noviembre - 8:00 p.m.

CARMEL CLUB CAMPESTRE VALOR POR PERSONA $300.000 TRAJE DE COCTÉL

Con la presentación especial de: Wilfrido Vargas & Fruko y sus Tesos

24Informes: Tel: 2558777 – 2558966 Fax: 3454361

email: acggp@acggp.org